Method for generating predetermined light, method for utilizing predetermined light, method for providing services using predetermined light, measurement / imaging method, optical property conversion element, light source unit, measurement unit, measurement device, predetermined light utilization device, and service provision system

Abstract

This invention provides a method for generating a predetermined light with desirable or relatively appropriate characteristics for various application fields and service provision fields that utilize light. Alternatively, it may also provide application methods or service methods that utilize this predetermined light. [Solution] A first object to be measured, consisting of a first component and a second component, and a second object to be measured, consisting only of the second component, are prepared, a first light is shone onto the first object to be measured, and a first spectral characteristic signal relating to the first object to be measured is collected from the second light obtained from the first object to be measured, The first light is irradiated onto the second object to be measured, a second spectral characteristic signal relating to the second object to be measured is collected from the third light obtained from the second object to be measured, and the absorbance characteristics of only the first component are extracted using the first spectral characteristic signal and the second spectral characteristic signal.

Description

[Technical Field]

[0001] This embodiment relates to the technology field of controlling the properties of light itself, the application field of light, or the field of providing services using light. [Background technology]

[0002] Light itself is known to possess various attributes, including not only wavelength characteristics, intensity distribution characteristics, and phase distribution characteristics (including wavefront characteristics), but also directivity and coherence.

[0003] Furthermore, known applications of light include imaging techniques that involve placing an image sensor at the imaging position of the target object, and applications that utilize spectral characteristic measurement techniques for the object being measured. In addition, applications such as imaging spectroscopy, which combines the above imaging techniques and spectral characteristic measurement techniques, have recently been developing. Beyond these, there are other applications that utilize the measurement results of light reflection, transmission, absorption, and scattering, or their temporal changes.

[0004] Furthermore, as a field of service provision utilizing light, there is a known technological field that provides services to users by utilizing information obtained in the aforementioned light-based application fields. In addition, there are other service provision methods that utilize light as a means of providing services to users, such as visualization and laser processing. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] V. Torres-Company, G. Minguez-Vega, J. Lancis, and A. T. Friberg, “Controllable generation of partially coherent light pulse with direct space-to-time pulse shaper,” Optics Letters Volume 32 ( Number 12 ) p.1608 - p.1610 (2007).

Summary of the Invention

Problems to be Solved by the Invention

[0006] To provide a method for generating a predetermined light having desirable or relatively appropriate characteristics in various application fields and service provision fields using light. Alternatively, without being limited thereto, an application method or a service method using the predetermined light may be provided.

[0007] Furthermore, to provide an optical property conversion element used for generating light having desirable or relatively appropriate characteristics in various application fields using light, or a light source unit, a measurement unit, a measuring device, a predetermined light utilization device, or a service provision system may be provided.

[0008] Also, an imaging method, spectroscopic measurement, optical measurement / measurement method using the predetermined light, or a measuring device using these methods may be provided.

Means for Solving the Problems

[0009] A first object to be measured, consisting of a first component and a second component, and a second object to be measured, consisting only of the second component, are prepared. A first light is shone onto the first object to be measured, and a first spectral characteristic signal relating to the first object is collected from the second light obtained from the first object to be measured. Alternatively, the first light is shone onto the second object to be measured, and a second spectral characteristic signal relating to the second object is collected from the third light obtained from the second object to be measured. A predetermined light utilization method or measurement / imaging method may be provided, in which the absorbance characteristics of only the first component are extracted using the first and second spectral characteristic signals.

[0010] Alternatively, the device may include a light source unit, a measurement unit, and a signal processing unit, wherein the light source unit emits a first light to irradiate a first object to be measured, the measurement unit receives a second light obtained from the first object to be measured, and collects a first spectral characteristic signal relating to the received second light. On the other hand, the light source unit emits the first light to irradiate a second object to be measured consisting only of the second component, the measurement unit receives a third light obtained from the second object to be measured, collects a second spectral characteristic signal relating to the received third light, and the signal processing unit uses the first spectral characteristic signal and the second spectral characteristic signal to extract the absorbance characteristics of only the first component.

[0011] Furthermore, the above-mentioned method / device for utilizing light may be applied to imaging or measurement, or a service provision method / service provision system may be constructed using the information obtained therefrom.

[0012] Here, the predetermined light is irradiated onto the object to be measured, first information is obtained from the predetermined light or the detected light obtained from the object to be measured, and then second information is obtained from the detected light using the first information. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a configuration diagram showing an example of the overall system overview. [Figure 2]Figure 2 is an explanatory diagram illustrating the relationships between the optical properties required (desired) for various application fields. [Figure 3] Figure 3 is an explanatory diagram illustrating the basic principles of optical processing in this embodiment. [Figure 4] Figure 4 is an explanatory diagram showing the optical characteristics to be operated / controlled in this embodiment and the location of that operation / control. [Figure 5A] Figure 5A is an explanatory diagram of an example in which the light intensity distribution is manipulated / controlled at or near the light-gathering surface / imaging surface. [Figure 5B] Figure 5B is an explanatory diagram of an example in which the light intensity distribution is manipulated / controlled in a distant region. [Figure 6A] Figure 6A is an explanatory diagram of one embodiment in which phase characteristics are manipulated / controlled at or near the focusing plane / imaging plane. [Figure 6B] Figure 6B is an explanatory diagram of another embodiment in which the phase characteristics are manipulated / controlled at or near the focusing / imaging plane. [Figure 6C] Figure 6C is an explanatory diagram illustrating an example of a method for generating a phase difference by utilizing differences in light paths within a photosynthetic site. [Figure 6D] Figure 6D is an explanatory diagram of an embodiment in which aberrations are generated in the far region. [Figure 7A] Figure 7A is an explanatory diagram of an embodiment in which phase-locking characteristics are manipulated / controlled in the far region. [Figure 7B] Figure 7B illustrates another embodiment of the optical property conversion element that performs operation / control of phase-locked characteristics. [Figure 7C] Figure 7C illustrates an example of an application of an optical property conversion element that manipulates / controls phase-locked characteristics. [Figure 8] Figure 8 is an explanatory diagram illustrating the principle by which an optical path length conversion element manipulates / controls the phase-locking characteristics. [Figure 9] Figure 9 is an explanatory diagram illustrating the effect of the optical path length conversion element in reducing noise within the spectral characteristics. [Figure 10] Figure 10 is an explanatory diagram illustrating the generation principle of multiple wave streams with different phases as they pass through a diffuser plate. [Figure 11]Figure 11 is an explanatory diagram showing the effect of reducing coherence when phase-locking characteristics and phase characteristics are used in combination. [Figure 12] Figure 12 is an explanatory diagram showing the effect of reducing speckle noise in laser light when phase-locking characteristics and phase characteristics are used in combination. [Figure 13] Figure 13 is an example diagram illustrating an evaluation method when operating / controlling phase-locked characteristics or operating / controlling phase characteristics. [Figure 14] Figure 14 is an example diagram illustrating an evaluation method when the phase characteristics are manipulated / controlled. [Figure 15] Figure 15 is an explanatory diagram illustrating other evaluation methods when the phase characteristics are manipulated / controlled. [Figure 16] Figure 16 is an explanatory diagram illustrating a detailed example of the optical arrangement within the light source. [Figure 17A] Figure 17A is an explanatory diagram illustrating an example structure within an optical property conversion block that is placed in the middle of the optical path to transform its optical properties. [Figure 17B] Figure 17B is an explanatory diagram illustrating an application example of an internal structure of an optical property conversion block that is placed in the middle of an optical path to transform its optical properties. [Figure 18A] Figure 18A is an explanatory diagram showing the absorbance (linear absorption ratio) characteristics of glucose dissolved in water. [Figure 18B] Figure 18B is an explanatory diagram showing the absorbance characteristics of glucose alone. [Figure 19] Figure 19 is an explanatory diagram illustrating the relative absorbance characteristics of water, silk, and polyethylene. [Figure 20A] Figure 20A shows an example of a measurement setup for measuring the characteristics of the subject. [Figure 20B] Figure 20B shows an enlarged view of the measurement area when measuring subject characteristics. [Figure 20C] Figure 20C is an explanatory diagram showing the relationship between the measurement location within the measurement area and the spectral characteristics obtained from it. [Figure 20D] Figure 20D is an explanatory diagram of the measurement method for the entire two-dimensional region of the measurement target. [Figure 20E] Figure 20E is an explanatory diagram of the measurement method for a three-dimensional region of the object to be measured, including the depth direction. [Figure 20F] Figure 20F is an explanatory diagram showing the detection accuracy in the depth direction in a three-dimensional domain measurement method. [Figure 21A] Figure 21A illustrates the principle of a measurement method that combines spectroscopic measurement and imaging. [Figure 21B] Figure 21B is an explanatory diagram of the image formation direction in a measurement method that combines spectroscopic measurement and imaging. [Figure 22A] Figure 22A is an explanatory diagram of the higher-level hierarchical structure of a service delivery platform that combines spectroscopic measurements and imaging. [Figure 22B] Figure 22B is an explanatory diagram illustrating an example of the configuration within a data processing block located at a lower level of a service delivery platform that combines spectroscopic measurements and imaging. [Figure 23] Figure 23 is an explanatory diagram illustrating an example procedure from data cube signal collection to analysis and service provision. [Figure 24] Figure 24 is an explanatory diagram showing an application example of this embodiment. [Figure 25] Figure 25 is an explanatory diagram illustrating another application example of this embodiment. [Figure 26A] Figure 26A is an explanatory diagram showing the information extraction and flow in this embodiment. [Figure 26B] Figure 26B is a classification diagram illustrating the information content extracted in this embodiment. [Figure 26C] Figure 26C shows the methods for removing disturbance noise for each measurement location / content within the object being measured. [Figure 27A] Figure 27A shows experimental results of wave freight characteristics related to optical noise reduction. [Figure 27B] Figure 27B is an explanatory diagram of the expected mechanism by which wave chains are generated. [Figure 28A] Figure 28A shows a diagram illustrating the principle of the optical noise generation cause in this embodiment from a different perspective. [Figure 28B]Figure 28B is an explanatory diagram showing the relationship between the mode characteristics of a multimode fiber and optical noise reduction. [Figure 28C] Figure 28C is an explanatory diagram illustrating the relationship between an optical property conversion element and a multimode fiber. [Figure 28D] Figure 28D is an explanatory diagram of an embodiment of an optical noise reduction method. [Figure 28E] Figure 28E is an illustrative diagram of another embodiment of the optical noise reduction method. [Figure 28F] Figure 28F is an explanatory diagram illustrating an application example of an optical noise reduction method. [Figure 28G] Figure 28G is an explanatory diagram illustrating the experimental results showing the optical noise reduction effect in this embodiment. [Figure 29A] Figure 29A is an explanatory diagram of the structure of the container for holding the object to be measured. [Figure 29B] Figure 29B is an explanatory diagram showing an example of a method for placing the object to be measured inside the holding container. [Figure 29C] Figure 29C is an explanatory diagram of another embodiment of the container structure for holding the object to be measured. [Figure 30A] Figure 30A is an explanatory diagram of the measurement optical system used when measuring the overall characteristics of the object being measured. [Figure 30B] Figure 30B is an explanatory diagram of problems that occur when measuring a localized area within an object being measured. [Figure 30C] Figure 30C is an explanatory diagram of the measurement optical system for measuring a local area within an object to be measured in this embodiment. [Figure 31A] Figure 31A is an explanatory diagram illustrating the interaction between light and the object being measured. [Figure 31B] Figure 31B is an explanatory diagram of the absorption band wavelengths for each component that makes up a biological system. [Figure 31C] Figure 31C is an explanatory diagram summarizing the wavelength-dependent characteristics for each interaction with light within the object being measured. [Figure 31D] Figure 31D is an explanatory diagram of the baseline correction method for the light attenuation spectral characteristics obtained from the object being measured. [Figure 32A]Figure 32A shows the difference in absorbance characteristics before and after baseline correction obtained from a 100 μm thick silk scarf. [Figure 32B] Figure 32B shows the difference in absorbance characteristics before and after baseline correction obtained from a transparent polyethylene sheet with a thickness of 30 μm. [Figure 32C] Figure 32C is an explanatory diagram of the method for predicting the content ratio of constituent components from corrected absorbance characteristics. [Figure 33A] Figure 33A shows the basic processing method for extracting information about spectral data in this embodiment. [Figure 33B] Figure 33B shows another processing method for extracting information about spectral data in this embodiment. [Figure 33C] Figure 33C shows the sequence of processing flows in this embodiment, from the user's initial operation to measurement / analysis / notification of results. [Figure 34A] Figure 34A shows the basic data processing method in this embodiment for spectral characteristics and image signals that change over time. [Figure 34B] Figure 34B is an explanatory diagram of the method for generating a multiple parallel bandpass filter used for reference signal extraction. [Figure 34C] Figure 34C shows another embodiment of the data processing method for time-series changing spectral characteristics and image signals. [Figure 34D] Figure 34D shows an example of an application of a method for processing spectral characteristics and image signals using pulsed light emission exposure. [Figure 35] Figure 35 is a diagram illustrating the features of the charge storage type signal receiver. [Figure 36A] Figure 36A is an explanatory diagram of an example of signal processing (data processing) leading to the generation of a reference signal after the removal of the DC component. [Figure 36B] Figure 36B is an explanatory diagram illustrating an example of a second information extraction method, either wavelength-wise or pixel-wise. [Figure 37A] Figure 37A shows the changes in the spectral characteristics of nerve cells during and immediately after firing. [Figure 37B] Figure 37B shows a diagram illustrating the estimated mechanism of neuronal firing. [Figure 37C] Figure 37C shows a diagram illustrating the estimated mechanism of ATP hydrolysis during ion pump operation. [Figure 38] Figure 38 shows a method for synchronizing the phase of a reference signal with respect to a time-series changing measurement signal. [Figure 39A] Figure 39A shows an explanatory diagram of the internal structure of the light source unit, which is composed of a combination of a DC light-emitting unit and a modulation light-emitting unit. [Figure 39B] Figure 39B illustrates the difference in measurement content between the DC emission period and the modulation emission period in this embodiment. [Figure 39C] Figure 39C is an explanatory diagram illustrating an example of timing control during data processing of spectral characteristics and image signals using modulation emission. [Figure 40A] Figure 40A is a detailed procedure diagram illustrating the individual identification process using visible light. [Figure 40B] Figure 40B is a detailed diagram illustrating the procedure for extracting a predetermined region within an individual. [Figure 41A] Figure 41A is an explanatory diagram illustrating the method for outputting and transferring compressed data cube information after spectral characteristic analysis in this embodiment. [Figure 41B] Figure 41B is an explanatory diagram illustrating an example of the data cube information transfer format in this embodiment. [Modes for carrying out the invention]

[0014] Chapter 1 System Overview Used in This Embodiment Figure 1 shows the system used in this embodiment. Light emitted from the light source unit 2 is irradiated onto the object 20 via the light propagation path 6. The light obtained from the object 20 is then incident on the measurement unit 8 via the light propagation path 6 again. However, the light emitted from the light source unit 2 may also be incident directly on the measurement unit 8 via the light propagation path 6. In another embodiment, light emitted from the light source unit 2 may reach the display unit 18 via the light propagation path 6, and predetermined information may be displayed on this display unit 18.

[0015] In this embodiment, the measuring device 12 consists of a light source unit 2, a measurement unit 8, and a system control unit 50. An application field (various optical application fields) adaptation unit 60 exists outside the measuring device 12. Each of the parts 62-76 within this application field (various optical application fields) adaptation unit 60 is capable of individually exchanging information with the system control unit 50.

[0016] For example, the information obtained from the measurement results in the measurement unit 4 is used in conjunction with the various parts 62 to 76 within the application field (various optical application fields) adaptation unit 60 to provide services to the user.

[0017] In this embodiment, the service provision system 14 consists of the measuring device 12, the application field (various optical application fields) adapting unit 60, and the external system 16, and is designed to provide all kinds of services to the user. Here, the remaining part of the service provision system 14, excluding the external system 16, functions independently as the optical utilization device 10.

[0018] The optical application fields 100 to which this embodiment applies are diverse, as shown in Figure 2. However, they are not limited to these; all application fields 100 that involve light in some form (including displays using light) are subject to this embodiment.

[0019] Figure 2 shows a table listing the required (desired) optical properties 102 for each optical application field 100. In particular, this embodiment can conform to the required (desired) optical properties 102 enclosed in the square frame.

[0020] Chapter 2 Overview of the basic optical operations used in this embodiment Figure 3 illustrates the basic principle of optical operation in this embodiment. Specifically, a first light 202 having a first optical property is formed in the first optical path 222, and a second light 204 having a second optical property is formed in the second optical path 224. Subsequently, the first light 202 and the second light 204 are combined in the photosynthesis site 220 to form a predetermined light 230. Here, at least a portion of the space between the first optical path 222 and the second optical path 224 is located in a different spatial location. Furthermore, the first optical property of the first light 202 and the second optical property of the second light 204 are different from each other. Moreover, a third light 206 having a third optical property may be formed in the third optical path 226. In this case, at least a portion of the third optical path 226 may be located in a different spatial location from the first optical path 222 and the second optical path 224.

[0021] Here, as a method of arranging at least a portion of the space between the first optical path 222, the second optical path 224, and the third optical path 226 in different spatial locations, wavefront division may be performed on the initial light 200 to individually extract each light 202 to 206. That is, regions 212 to 216 are arranged in different locations on the optical cross-section of the incident initial light 200 (the plane obtained by cutting the light beam composed of the initial light 200 with a plane perpendicular to the direction of propagation of the initial light 200) or on the wavefront of the initial light 200, and each light 202 to 206 is individually extracted.

[0022] The above technical details will now be explained again from the perspective of the structure of the optical property conversion element 210 that realizes the optical effect. That is, the optical property conversion element 210 used in this embodiment includes a first region 212 and a second region 214 that are different from each other. The operation / control parameters 280 that describe the characteristics of each region 212 and 214 are different from each other. Therefore, the first light 202 after passing through the first region 212 and the second light 204 after passing through the second region 214 have different optical properties. Furthermore, the optical property conversion element 210 has a spatial structure that facilitates the synthesis of the first light 202 and the second light 204 at the photosynthesis site 220 to form a predetermined light 230.

[0023] As a concrete example of a spatial structure that facilitates the formation of a predetermined light 230 by combining the first light 202 and the second light 204, the incident initial light 200 may be wavefront-divided and separated into two lights 202 and 204. That is, a spatial structure may be adopted in which the first region 212 is arranged in a predetermined region within the cross-section of the light beam obtained by cutting the light beam with a plane perpendicular to the direction of propagation of the incident initial light 200. Then, a spatial structure may be adopted in which the second region 214 is arranged in another region within the above cross-section of the light beam. However, as an alternative method, the initial light 200 may be subjected to amplitude division or intensity division.

[0024] Another application example is to provide a third region 216 within the optical property conversion element 210, creating a structure that allows for the extraction of the third light 206 that has passed through this third region 216.

[0025] The optical operation area 240 in Figure 3 includes the object 20 in Figure 1, the display unit 18, the measurement unit 8, and the application field (various optical application fields) adaptation unit 60.

[0026] Figure 4 provides a table listing the optical characteristics 252 that are operated / controlled by the optical characteristic conversion element 210 described in Figure 3, and the locations 258 where the optical characteristic conversion element 210 is placed in this embodiment.

[0027] In the operation / control items 250 of Figure 4, we will first explain the optical characteristics 252 that are the target of operation / control by the optical characteristic conversion element 210. According to the classification 260 of these target optical characteristics 252, they can be classified into three categories: 'the light intensity distribution within the cross-section of the initial light beam 200', 'the phase characteristics or wavefront characteristics within the cross-section of the initial light beam 200', and 'the phase synchronization characteristics between the optical elements (wave elements) contained within the operated / controlled light beam'. Specific examples 270 of the optical characteristic conversion element 210 corresponding to each classification 260 and the operation / control parameters 280 for each specific example are described below.

[0028] In the optical property conversion element 210 described in this embodiment, the incident initial light 200 is wavefront-splitting or amplitude-splitting / light quantity-splitting, and the optical properties are manipulated or controlled by changing the value of the parameter 280 that is operated / controlled for each of the split light segments.

[0029] When using a slit or pinhole with discretely changing transmittance or reflectance as a specific optical property conversion element 210 to manipulate / control the light intensity distribution within the cross-section of the initial light beam 200, the optical properties are manipulated / controlled by changing the period (pitch), slit width, and pinhole size.

[0030] Furthermore, as a specific example (270), when using transmissive or reflective gradation elements (gradation providing optical components), the gradation characteristics of their transmittance and reflectance are manipulated / controlled. However, it is not limited to this; the light intensity distribution of light entering the waveguide is also manipulated / controlled to manipulate / control the modes of light propagating within the waveguide (this specific example will be described later using Figure 5B).

[0031] If the light intensity distribution within the luminous beam cross-section of the initial light 200 is to be manipulated / controlled by other means, the transmittance or the light intensity distribution control value after reflection may be manipulated / controlled.

[0032] When using a diffuser as a specific optical property conversion element 210 for manipulating / controlling the phase characteristics or wavefront characteristics within the initial light 200, it is not limited to the average roughness "Ra" of its surface or the average pitch "Pa" of its surface irregularities. In addition, the surface-direction period for each predetermined Fourier component obtained when the surface irregularities are Fourier transformed, or the ratio of vertical amplitude to period, may also be manipulated / controlled.

[0033] Furthermore, when using diffraction gratings or holograms, the period and the width ratio between the top and bottom surfaces may be manipulated / controlled. Diffraction gratings and holograms are often composed of two parallel planes forming the top and bottom surfaces (in blazed gratings, one plane has an inclination). However, this is not limited to this; the number of plane layers may also be changed. The theoretical analysis conducted in Chapter 3 suggests that increasing the number of plane layers tends to improve the reduction effect of at least one of optical noise and coherence.

[0034] When using various aberration generating components (wave aberration generating components), the optical design of the focusing lens or the bending direction of the focusing lens may be changed. It is also known that spherical aberration occurs when a thick parallel plate is placed in the path of the converging light, and coma aberration occurs when an inclined plate or non-parallel plate is placed. Therefore, the optical characteristics can be manipulated / controlled by changing the thickness of the parallel plate, the inclination angle, or the interplane angle within the non-parallel plate.

[0035] When a stepped plate with a step "t" is placed in the optical path within the cross-section of the initial light beam of 200, an optical path length difference of "(n-1)t" occurs. Here, "n" represents the refractive index of the stepped plate. A phase difference corresponding to this optical path length difference then occurs. In this case, the optical properties can be manipulated / controlled by changing the step on the surface of the stepped plate (the thickness step of the flat plate).

[0036] Furthermore, even if the wavefront characteristics after transmission or reflection are changed by any other method, it becomes possible to manipulate / control the phase characteristics (wavefront characteristics).

[0037] As will be described in detail in Chapter 3 using Figure 8, the phase-locking characteristics can be manipulated / controlled by using an optical path length changer as the optical characteristic conversion element 210. In this case, it is desirable that the optical path length generated within the optical path length changer is greater than the coherence length, which will be described later using Equation 1. In this embodiment, the optical characteristic conversion element 210 described above may be placed on the light converging plane, the image pattern forming plane, the aperture plane, or in the nearby field 170. In other embodiments, it may also be placed in the far field 180, which is located far from the light converging plane or the image pattern forming plane.

[0038] In this embodiment, the Fraunhofer diffraction area that is far away from the focusing plane, imaging plane, or aperture plane is called the far region 180. On the other hand, the region closer to the Fresnel diffraction area that is located nearby is called the nearby region.

[0039] To explain in more detail, let "D" be the diameter of the luminous beam cross-section of the initial light 200 or the length of one side of the square aperture, and let "z" be the direction of propagation of the initial light 200. Also, let "λ0" represent the specific wavelength contained within the initial light 200.

[0040] In this case, diffraction theory is “-D 2 / λ0 ≤ z ≤ +D 2 The range within / λ0” is said to be the Fresnel diffraction region. Therefore, in this embodiment as well, the above range is defined as the neighboring region 170. On the other hand, “ |z| > +D 2 The range / λ0” is known as the Fraunhofer diffraction region. Therefore, in this embodiment as well, the above range is defined as the far region 180.

[0041] By the way, when the initial light 200 is divergent light with a divergence angle “θ”, if it is far from the condenser surface or imaging surface or aperture surface, the beam cross-sectional size increases and measurement by the measurement unit 8 becomes impossible. In the present embodiment, it is premised on the measurability by the measurement unit 8. Therefore, in the present embodiment, the upper limit value of the far region 180 is also defined.

[0042] When the value of the beam cross-sectional size “D” on the condenser surface or imaging surface or aperture surface is relatively small, the beam cross-sectional size with respect to the distance “z” from the condenser surface or imaging surface or aperture surface is approximated by “2zNA”. By the way, in vacuum, “NA≡2sinθ” is defined. Therefore, the detected light amount at a position “z” away is “D 2 / 4NA 2 z 2 ” less than the detected light amount on the condenser surface or imaging surface or aperture surface. Therefore, in the present embodiment, considering the upper limit value of the distance “z” corresponding to the far region 180, “D 2 / λ0 < |z| < 1×10 8 D 2 / 4NA 2 ” is defined as the range of the far region 180. Further, considering ensuring the measurement accuracy by the measurement unit 8, the range of the far region 180 is preferably “D 2 / λ0 < |z| < 1×10 4 D 2 / 4NA 2 ”.

[0043] According to the diffraction theory of optics, when the condenser surface or imaging surface / aperture surface position coincides with the focal plane of the condenser lens, it is known that the vicinity of the pupil plane of this condenser lens or the vicinity of the aperture surface of the condenser lens corresponds to the far field 180 with respect to the condenser surface or imaging surface. Therefore, in the present embodiment, not limited to the above numerical range, the positions in the vicinity of the pupil plane of the condenser lens or the vicinity of the aperture surface of the condenser lens are also included in the “far region 180”.

[0044] Figure 4 outlines the embodiment. Next, specific embodiments will be described using Figures 5A to 7C. To clarify the correspondence between the contents of Figures 5A to 7C and the classification contents 260 and the placement locations 258 of the optical characteristic conversion elements 210 shown in Figure 4, symbols 290 are assigned to each specific example 270 and the placement location 258 of the optical characteristic conversion elements 210 in Figure 4.

[0045] Figure 5A shows a specific embodiment example corresponding to embodiment "N01" in the table in Figure 4. Specifically, in Figure 5A, a slit is used as the optical characteristic conversion element 210, which is placed on the light-collecting surface, the imaging surface / aperture surface, or its vicinity 170, to manipulate / control the light intensity distribution there.

[0046] The light-transmitting region within this slit corresponds to the first region 212. The light-shielding region within the slit corresponds to the second region 214. In Figure 5A, the light-transmitting region within the slit (the first region) is used to selectively extract the first light rays 202-1 to -3 heading towards the photosynthesis site 220 from the initial light 200. However, this is not the only method; selective extraction of light heading towards the photosynthesis site 220 may also be performed by utilizing partial reflection of light.

[0047] The first light rays 202-1 to -3 that have passed through each first region 212 become parallel light after passing through the collimating lens 318. The regions before and after passing through the collimating lens 318 are then used as photosynthesis sites 220. The first light rays 202-1 to -3 synthesized in these photosynthesis sites 220 form predetermined light 230.

[0048] As an example of the optical manipulation area 240, Figure 5A shows that the imaging unit of a hyperspectral camera used in the field of imaging spectroscopy is composed of a spectroscopic element (blazed grating) 320, a focusing lens 314, and an image sensor 300. To widen the imaging field of view, the imaging lens 310 or the optical characteristic conversion element 210 (slit) is configured to be movable in the X direction 322. The measurement technique using this imaging spectroscopy will be described in detail later using Figures 21A and 21B.

[0049] The embodiment of the optical operation location 240 when using a specific embodiment example corresponding to embodiment "N01" is not limited to Figure 5A, but an embodiment of the optical operation location 240 corresponding to any application set in the application field (various optical application fields) adapting section 60 in Figure 1 can be adopted.

[0050] Figure 5B shows a specific example of an embodiment corresponding to embodiment "F02" in the table in Figure 4. In other words, in Figure 5B, an optical property conversion element 210 is placed in the far region 180, and the intensity distribution (light quantity distribution) of the light beam cross-section obtained by cutting the initial light 200 with a plane perpendicular to the direction of propagation is manipulated / controlled.

[0051] In the first region 212 within the optical property conversion element 210, light is not blocked (it has a light transmittance of almost "100%)", so the initial light 200 passing through the first region 212 travels in a straight line. On the other hand, in the third region 216, the light transmittance is set to almost "0%", so the initial light 200 that reaches this region is blocked. Furthermore, in the second region 214, the light transmittance changes depending on the location through which the light passes.

[0052] The intensity distribution of the focused light 218 obtained after focusing with the focusing lens 314 can be changed from the intensity distribution in (a) to the intensity distribution in (b) by inserting the optical property conversion element 210 having the above characteristics.

[0053] By aligning the converged light position 218 of the focusing lens 314 with the entrance surface of the optical fiber (waveguide) 330, it becomes possible to optimize the mode control of light propagating within the optical fiber (waveguide) 330 by manipulating / controlling the light intensity distribution using the optical characteristic conversion element 210 described above.

[0054] As a specific embodiment of the optical operation location 240 in Figure 3, Figure 5B shows an embodiment of the optical propagation path 6 (Figure 1) combining an optical fiber (waveguide) 330 and a measurement unit 8. The embodiment of the optical operation location 240 when using the specific embodiment example corresponding to embodiment "F02" is not limited to Figure 5B, but an embodiment of the optical operation location 240 corresponding to any application set in the application field (various optical application fields) adaptation section 60 in Figure 1 can be adopted.

[0055] Figure 6A(a) shows a specific embodiment corresponding to embodiment “N11” in the table in Figure 4. Specifically, in Figure 6A(a), a diffuser plate is placed as an optical characteristic conversion element 210 at the position (on the focusing surface or on the imaging surface) of the converged light 218 of the initial light 200 focused by the focusing lens 314, and the phase characteristics (wavefront characteristics) of the converged light 218 are manipulated / controlled. The first / second light 202 and 204 that have passed through this diffuser plate enter the optical fiber (waveguide) 330. Therefore, in the specific embodiment shown in Figure 6A(a), the inside of the optical fiber (waveguide) 330 plays the role of a photosynthesis site 220. Furthermore, this optical fiber (waveguide) 330 also plays the role of an optical propagation path 6 that guides the predetermined light 230 to an arbitrary location.

[0056] As a specific embodiment of the optical operation location 240 in Figure 3, Figure 6A(a) shows a combination of a movable imaging lens 312 and an optical recording / playback medium 26, which serves as a storage device for collected information 74. However, it is not limited to this, and any embodiment of the optical operation location 240 corresponding to any application set out in the application field (various optical application fields) adaptation section 60 in Figure 1 can be adopted.

[0057] Here, the operation / control parameter 280 for the diffuser plate operates / controls the characteristics between the first region 212 and the second region 214 using the various setting values ​​listed in the table in Figure 4. For example, when changing the average roughness "Ra1" in the first region 212 and the average roughness "Ra2" in the second region 214, the condition "Ra2 / Ra1 > 1" must be satisfied in order to achieve the effect described later in Chapter 3. According to actual experimental results, the effect improves further when the condition "Ra2 / Ra1 ≥ 1.5" is also satisfied. And it is desirable to satisfy the condition "Ra2 / Ra1 ≥ 3".

[0058] Figure 6A(b) shows the characteristics of the maximum incident angle "θ" of light that can propagate within the core region 332 of the optical fiber (waveguide) 330. When the maximum incident angle of light that can propagate within the core region 332 is expressed as "θ", the value of "NA = sinθ" is determined for each optical fiber (waveguide) 330. Therefore, it is necessary to set the incident angle of light entering the optical fiber (waveguide) 330 so that it is less than or equal to the "NA value" specified for each optical fiber (waveguide) 330.

[0059] Therefore, when an optical characteristic conversion element 210 that manipulates / controls the phase characteristics (wavefront characteristics) is placed near the incident surface of the optical fiber (waveguide) 330, it is necessary to consider the incident angle range to the optical fiber (waveguide) 330 as described above.

[0060] When a diffuser plate is used as the optical property conversion element 210 for manipulating / controlling the phase characteristics (wavefront characteristics), the average period "Pa" of its surface roughness must satisfy the condition "Pa ≥ λ / NA". Here, "λ" represents the wavelength of light propagating within the optical fiber (waveguide) 330. Similarly, when a diffraction grating or hologram is used, the pitch "Pa" of the diffraction grating or hologram must also satisfy "Pa ≥ λ / NA". Furthermore, satisfying the condition "Pa ≥ λ / (4NA)" further stabilizes the performance.

[0061] In Figure 6A(a), when changing the average period of surface roughness "Pa1" and "Pa2" between the first region 212 and the second region 214 in order to achieve the effects described later in Chapter 3, the condition "Pa2 / Pa1" must be satisfied. Also, for the reasons mentioned above, it is necessary to set "Pa1 ≥ λ / NA" and "Pa2 ≥ λ / NA". Furthermore, if the conditions "Pa1 ≥ λ / (4NA)" and "Pa2 ≥ λ / (4NA)" are satisfied, the performance will be even more stable.

[0062] In the embodiment shown in Figure 6A(a), the optical property conversion element 210 (diffuser plate) is divided into two regions: a first region 212 and a second region 214. However, the optical property conversion element 210 (diffuser plate) is not limited to this and may be divided into three or more regions, or even four or more regions.

[0063] Furthermore, in the optical property conversion element 210 shown in the embodiment example in Figure 6A(a), the first region 212 and the second region 214 are composed of diffusers with different operation / control parameters 280. However, it is not necessarily required that the first region 212 and the second region 214 be composed of the same diffuser. In other words, they may be combined with other specific examples 270 that perform operation / control of phase characteristics (wavefront characteristics) within the same optical property conversion element 210. For example, the first region 212 within the same optical property conversion element 210 may be composed of a diffuser, and the second region 214 may be composed of a diffraction grating / hologram.

[0064] Figure 6B shows a specific embodiment corresponding to embodiment "N12" in the table in Figure 4. Specifically, in Figure 6B, a diffraction grating or hologram is placed as an optical property conversion element 210 at the position (on the focusing surface or on the imaging surface) of the converged light 218 of the initial light 200 focused by the focusing lens 314, and the phase characteristics (wavefront characteristics) of the converged light 218 are manipulated / controlled.

[0065] In the optical property conversion element 210 shown in Figure 6B, the number of steps in the plane, the pitch (period) of the steps, and the plane width ratio (Duty) between the top and bottom surfaces are changed between the first region 212 and the second region 214. If a diffraction grating or hologram is used as the optical property conversion element 210, the diffraction angle may exceed the "NA value" of the optical fiber (waveguide) 330 mentioned above. To address this, Figure 6B uses an optical guide (waveguide) 340 that can obtain a large "NA value".

[0066] As a specific example of the optical manipulation location 240 in Figure 3, Figure 6B shows an illumination system in which predetermined light 230 emitted from an optical guide (waveguide) 340 is irradiated onto an object 28 to be illuminated. However, the system is not limited to this, and any embodiment of the optical manipulation location 240 corresponding to any application set out in the application field (various optical application fields) adaptation section 60 in Figure 1 can be adopted.

[0067] As shown in Figures 6A(b) and 6B, when a diffuser plate or diffraction grating / hologram is used as a specific example 270 of the optical property conversion element 210 that manipulates / controls the phase characteristics (wavefront characteristics), diffracted light is generated according to the periodicity along the surface direction of the optical property conversion element 210 (for example, the average period of surface roughness "Pa"). In this embodiment, the generation of this diffracted light is used to manipulate / control the phase characteristics (wavefront characteristics) with respect to the initial light 200.

[0068] Figure 6C illustrates an example of a method for generating a phase difference by utilizing the difference in optical paths within the optical guide 340 or the core region 332 of the optical fiber 330, which are used as the photosynthesis site 220. The zero-order diffracted light 232 and 234 with respect to the surface of the optical property conversion element 210 travels in a straight line along the direction of propagation of the initial light 200. On the other hand, the first-order diffracted light 236 and 238 generated by the periodic uneven shape of the surface of the optical property conversion element 210 travels in directions of angles "θ1" and "θ2" within the optical guide 340 or the core region 332 of the optical fiber 330.

[0069] Incidentally, the propagation angles "θ1" and "θ2" of the first-order diffracted lights 236 and 238 change according to the period or average period "Pa1" in the first region 212 and the period / average period "Pa2" in the second region 214 in the optical property conversion element 210. Therefore, as shown in FIG. 6C, when the periods or average periods "Pa1" and "Pa2" are changed between the first region 212 and the second region 214, the optical path lengths of the first-order diffracted lights 236 and 238 when passing through the optical guide 340 or the core region 332 of the optical fiber 330 change. Therefore, in the present embodiment, it is necessary that the value of "Pa2 / Pa1" exceeds "1" (1 < Pa2 / Pa1), and it is desirable to have a relationship of "1.2 ≦ Pa2 / Pa1".

[0070] As described using FIG. 6A(b), there is a relationship of "Pa1 = λ / nsinθ1" and "Pa2 = λ / nsinθ2" between the propagation angles "θ1", "θ2" of the first-order diffracted lights 236, 238 and "Pa1", "Pa2". Here, "n" represents the refractive index in the optical guide 340 or the core region 332 of the optical fiber 330. Therefore, if "Pa2" is too large, "θ2 ≒ 0", and no optical path length difference occurs between the zero-order diffracted light 234 and the first-order diffracted light 238.

[0071] On the other hand, as a condition for the first-order diffracted light 236 to stay in the core region 332 of the optical fiber 330, it is necessary to ensure "Pa1 ≧ λ / NA" (preferably "Pa1 ≧ λ / (4NA)"). (From the above condition of "1 < Pa2 / Pa1", it is necessarily necessary to satisfy the conditions of "Pa2 ≧ λ / NA" and "Pa2 ≧ λ / (4NA)".) For the above reasons, it is necessary to set an upper limit for the value of "Pa2 / Pa1".

[0072] Summarizing the above, in the present embodiment, as a condition for the value of "Pa2 / Pa1", "1 < Pa2 / Pa1 < 10000" (preferably "1.2 ≦ Pa2 / Pa1 ≦ 1000") is set.

[0073] FIG. 6D shows a specific embodiment example corresponding to the embodiment "F13" in the list of FIG. 4. We have already explained that spherical aberration occurs when a thick parallel plate is placed in the path of a light-gathering lens 314, and coma aberration occurs when an inclined plate is placed in the same path. Therefore, in the specific example shown in Figure 6D, an optical characteristic conversion element 210 is placed in the far-field region 180 to generate various aberrations. Specifically, a spherical aberration generating element 352 using a parallel plate is placed as the first region 212 within the optical characteristic conversion element 210. A coma aberration generating element 354 using an inclined plate is placed in the second region 214. In Figure 6D, the spherical aberration generating element 352 using a parallel plate and the coma aberration generating element 354 using an inclined plate are integrally formed. However, the spherical aberration generating element 352 and the coma aberration generating element 354 using an inclined plate may be separated.

[0074] When aberrations are generated using this method, if the amount of aberration is small, the effect of manipulating / controlling the phase characteristics (wavefront characteristics) will not be apparent. Conversely, if the amount of aberration is too large, the light will not be focused, and therefore light will not enter the optical fiber (waveguide) 330. Accordingly, in this embodiment, the range of the RMS (root mean square) value of the generated wavefront aberration is set to 0.5λ or more and 100λ or less (preferably 0.3λ or more and 1000λ or less).

[0075] As a specific embodiment of the optical operation location 240 in Figure 3, Figure 6D shows a rotatable 324 rotating mirror 316 placed in the optical path where a predetermined light 230 is focused onto the screen 326 by the imaging lens 312, enabling the operation 324 of the focused spot on the screen 326. In this way, the function of the display unit 18 (Figure 1) is achieved. However, it is not limited to this, and any embodiment of the optical operation location 240 corresponding to any application set in the application field (various optical application fields) adaptation section 60 in Figure 1 can be adopted.

[0076] Figure 7A shows a specific embodiment corresponding to embodiment "F21" in the table in Figure 4. Specifically, an optical path length conversion element is placed in the far region 180 of the initial light 200 (for example, midway along the path of the parallel light beam), and the phase-locked characteristics are operated / controlled as an optical characteristic conversion element 210. The optical characteristic conversion element 210 (optical path length conversion element) is formed of a transparent medium having a refractive index "n".

[0077] In the optical property conversion element 210, the first region 212 and the second region 214 have a difference in thickness "t" with respect to the direction of propagation of the initial light 200. As a result, a difference in optical path length of "t(n-1)" occurs between the first region 212 and the second region 214. The thickness "t" is adjusted so that this value is greater than or equal to the coherence length "ΔL0" described later in Equation 1. Furthermore, setting the above numerical setting to "t(n-1) ≥ 2ΔL0" further improves the effect.

[0078] In Figure 7A, the optical path of the first light 202 that passes through the first region 212 to the focusing lens 314 corresponds to the first optical path 222. Similarly, the optical path of the second light 204 that passes through the second region 214 to the focusing lens 314 corresponds to the second optical path 224. The focusing lens 314 then focuses both the first light 202 and the second light 204 toward the entrance surface of the optical fiber (waveguide) 330.

[0079] When the first light 202 and the second light 204 pass together through the optical fiber (waveguide) 330, they are synthesized or combined to form a predetermined light 230. Therefore, the inside of this optical fiber (waveguide) 330 acts as a photosynthesis site 220.

[0080] Figure 7A shows an example where an optical fiber (waveguide) 330 is used as the photosynthesis site 220. However, the photosynthesis site 220 is not limited to this; an optical guide (waveguide) 340 may also be used. Furthermore, as shown in Figure 5A, the region where the first optical path 222 and the second optical path 224 spatially overlap may also be used as the photosynthesis site 220.

[0081] The inlet and outlet surfaces of the optical fiber (waveguide) 330 and optical guide (waveguide) 340 generally have an optically planar shape. In this embodiment, instead of an optically planar shape, the inlet or outlet surface of the optical fiber (waveguide) 330 and optical guide (waveguide) 340 may have a fine uneven shape (optical diffusion surface structure or diffraction grating structure). In this case, the inlet or outlet surface of the optical fiber (waveguide) 330 and optical guide (waveguide) 340 will have the function of a diffusion plate or diffraction grating / hologram as described as specific example 270 in Figure 4. As a result, the inlet or outlet surface of the optical fiber (waveguide) 330 and optical guide (waveguide) 340 can also perform the function of manipulating / controlling the phase characteristics (wavefront characteristics) without adding a new optical characteristic conversion element 210. In this case, both the phase-locking characteristics and the phase characteristics (wavefront characteristics) with respect to the initial light 200 can be manipulated / controlled simultaneously, further improving the optical noise reduction effect and coherence reduction effect. Furthermore, this allows for a simplification of the internal structure of the light source unit 2 and a reduction in cost.

[0082] The following describes effective uneven shapes when fine irregularities are provided on the entrance or exit surface of the optical fiber (waveguide) 330 or optical guide (waveguide) 340. First, we will explain the case where fine irregularities are formed in the structure of a diffraction grating or hologram. Let "t" represent the amount of mechanical step difference between the top and bottom surfaces of the diffraction grating or hologram structure, and let "n" represent the refractive index inside the optical guide (waveguide) 340 or the core region 332 of the optical fiber (waveguide) 330. Then, the above mechanical step difference creates an optical path length difference of "t(n-1)". In this embodiment, the effect becomes apparent when this optical path length difference is "λ / 16" or greater. If we set the wavelength "λ" to "400nm" and "n≈1.5", then "t ≧ λ / 16(n-1) ≈ 50nm" is obtained. Therefore, if the amplitude value of the fine irregular shape is greater than "50 nm", the effect described in Chapter 3 will occur.

[0083] On the other hand, if the amplitude of the fine irregularities is too large, the stability of operation / control will be compromised. Specifically, if the optical path length difference exceeds "10000λ ≈ 4mm", the stability of operation / control will be compromised. Also, since the optical path length difference is given by "t(n-1)", it is desirable that the maximum allowable mechanical amplitude of the fine irregularities be "8mm" or less.

[0084] When the fine uneven surface is formed on the surface of the diffuser plate, it is expressed by the average roughness value "Ra" instead of the maximum amplitude. Considering the above considerations, if the range of "Ra value" for the fine uneven surface formed on the inlet or outlet surface of the optical fiber (waveguide) 330 or optical guide (waveguide) 340 can be set to "50nm ≤ Ra ≤ 8mm" (preferably "13nm ≤ Ra ≤ 2mm"), the effects described in Chapter 3 can be achieved.

[0085] As a specific embodiment of the optical operation location 240 in Figure 3, Figure 7A describes an example of an optical system that performs hologram recording on a measurement target 22 using an optical recording / reproduction medium 26. Specifically, predetermined light 230 exiting the optical fiber (waveguide) 330 is converted into parallel light by a collimating lens 318, and the reference light reflected by the mirror 376 and the light reflected from the measurement target 22 are combined by a half mirror 370. The resulting combined light is then irradiated onto the optical recording / reproduction medium 26 to perform hologram recording. However, the system is not limited to this, and embodiments of the optical operation location 240 corresponding to any application set out in the application field (various optical application fields) adaptation section 60 in Figure 1 can be adopted.

[0086] Figure 7B shows an example of an embodiment of the structure of an optical path length conversion element (optical characteristic conversion element 210 that manipulates / controls phase-locking characteristics). Figure 7B(a) shows a view from a direction along the propagation direction 348 of the initial light 200. Figure 7B(b) shows a view from the opposite direction of the propagation direction 348 of the initial light 200.

[0087] Figure 7B(c) shows a view of the initial light 200 from a cross-sectional direction perpendicular to the propagation direction 348. As shown in Figure 7B(c), the structure divides the initial light 200 into 48 regions (12 regions × 4 regions). In other words, it combines a division method in which the cross-section of the initial light 200 beam is divided into 12 in the angular direction and 4 in the radial direction.

[0088] As a method for dividing the material into 12 sections in the angular direction, 11 semi-circular transparent plates with a thickness of "1 mm" are bonded together while being rotated sequentially by "30 degrees" each. For the 4 sections in the radial direction, cylinders with different radii and a thickness of "12 mm" are bonded together while aligning their centers. As a result, the total thickness of each region changes by "1 mm" in each section. In this embodiment, the change in the total thickness of each region is set to "1 mm". However, the change in the total thickness of each region is not limited to this value and may be set to other values.

[0089] Figure 7C shows an application example of the structure of an optical path length conversion element (optical characteristic conversion element 210 that manipulates / controls phase-locking characteristics). In Figure 7C, as in Figure 7B, the optical path length conversion element is formed from a transparent material, and the initial light 200 passes through it. The structure is divided into 12 segments in the angular direction relative to the cross-section of the light beam of the passing initial light 200. When viewed in the optical propagation direction 348 of the initial light 200, the thickness of each segment changes from "1 mm" to "12 mm" in "1 mm increments".

[0090] In the structure shown in Figure 7C, the number of interface surfaces arranged along the optical propagation direction 348 of the initial light 200 passing through is designed to be the minimum number of "two surfaces each". If the planar accuracy of the interface surfaces at the interface between the transparent medium region and the air region constituting the optical path length conversion element is low, the wavefront accuracy of the light after passing through it deteriorates. Therefore, by setting the number of interface surfaces to the minimum number, the deterioration of the wavefront accuracy of the light after passing through the optical path length conversion element can be reduced.

[0091] Furthermore, in the structure shown in Figure 7C, the side surfaces 380 of the step differences between each region within the optical path length conversion element (i.e., the side surfaces of the boundary lines where the thickness changes within the optical path length conversion element) are all visible from a specific direction (a direction perpendicular to surface B). This structure improves the manufacturability of the optical path length conversion element and enables a reduction in the cost of the optical path length conversion element.

[0092] Figure 7C shows the structure of an optical path length conversion element (optical characteristic conversion element 210 that manipulates / controls phase-lock characteristics), but it may also have the function of manipulating / controlling phase characteristics (wavefront characteristics) at the same time. That is, at least one surface of the interface arranged perpendicular to the optical propagation direction 348 of the initial light 200 is not made an optical plane but has a fine uneven structure. Examples of this fine uneven structure 270 include a diffuser plate structure or a diffraction grating / hologram structure. As a result, this interface has the function of manipulating / controlling phase characteristics (wavefront characteristics). This allows for the simultaneous manipulation / control of both phase-lock characteristics and phase characteristics (wavefront characteristics) with a single optical element, improving the optical noise reduction effect and coherence reduction effect. Furthermore, the overall optical system can be simplified and the cost reduced.

[0093] Passing parallel light traveling in the same direction through the optical path length conversion element allows for more efficient manipulation / control of phase-locking characteristics. On the other hand, the direction of light traveling through an interface with a fine uneven structure is easily altered depending on the optical path (i.e., parallel light is easily converted into divergent light when it passes through an interface with a fine uneven structure). Therefore, it is desirable to provide a fine uneven structure to the interface surface located behind the optical propagation direction 348 among the two interface surfaces within the optical path length conversion element.

[0094] The same principles explained using Figure 7A apply to the effective range of dimensions for creating a fine uneven structure on the interface surface. Specifically, the effective range of dimensions for the uneven structure in this case can be defined as "50 nm or more and 8 mm or less" for the maximum amplitude of the step. On the other hand, when expressing the surface roughness using the average value "Ra", achieving "50 nm ≤ Ra ≤ 8 mm" (preferably "13 nm ≤ Ra ≤ 2 mm") will produce the effects described later in Chapter 3.

[0095] Chapter 3: Overview of the Basic Concept of This Embodiment and Explanation of the Results of the Experimental Verification and Theoretical Analysis When manipulating / controlling the phase-locking characteristic among the optical characteristics 252 of the light to be manipulated / controlled, an optical path length converter is used as the optical characteristic conversion element 210, as shown in Figure 4. This generates an optical path length difference between the first optical path 222 (see Figure 3) when the first light 202 passes through the first region 212 of the optical characteristic conversion element 210, and the second optical path 224 when the second light 204 passes through the second region 212. Alternatively, the optical cross-section of the initial light 200 may be wavefront-divided into the first light 202 and the second light 204 by wavefront division in the first region 212 and the second region 212. Furthermore, the light may be divided into the first light 202 and the second light 204 using, for example, amplitude division or intensity division, rather than being limited to wavefront division.

[0096] Furthermore, the optical path length difference may be generated between the third optical path 226 when the third light 206 passes through the third region 216 of the optical property conversion element 210 and the first optical path 222 mentioned above. An optical path length difference may also be generated between the third optical path 226 and the second optical path 224. As an application example, the optical path length difference may be generated for every four or more regions, not just three. In this embodiment, optical noise is significantly reduced by technically devising a way to make the above optical path length difference greater than the coherence length described later in Equation 1. The basic concept of this technical devising is as follows: By combining the first light 202 and the second light 204 at the photosynthesis site 220, an ensemble averaging effect is generated between the optical noise generated in the first light 202 and the optical noise generated in the second light 204. Furthermore, combining the third light 206 and other lights further improves the averaging effect. Figure 9 shows experimental results demonstrating that optical noise decreases with increasing wavefront division number (domain division number or optical path division number) (details will be provided later).

[0097] Figure 8 is a schematic diagram illustrating this basic concept. Generally, laser light is thought to have a "single wavelength," and it is easy to assume that the "envelope of the electric field amplitude is uniform everywhere" along the direction of laser light propagation. However, there are few lasers with a wavelength width of exactly "0." For example, many laser light sources with a wavelength width of "Δλ" of about "2 nm" are commercially available. When the central wavelength of this light source is taken as "λ0," all types of light undergo spatial propagation.

[0098]

number

[0099] The initial light 200, which is incident in the form of a continuous initial wave chain 400 as shown in Figure 8(a), is wavefront-divided when it passes through the optical property conversion element 210, which operates / controls the phase-locked characteristics. Figure 8(b) shows the spatial propagation state (wave chain state 406) of the first light 202 after passing through the first region 212 within the optical property conversion element 210 shown in Figure 3. Since the first light 202 is extracted as a result of wavefront division of the initial light 200, the amplitude in Figure 8(b) is smaller than the amplitude in Figure 8(a).

[0100] Figure 8(c) shows the spatial propagation state (wave-coupled state 408) of the second light 204 extracted after passing through the second region 214. The amplitude in Figure 8(c) is almost the same as that in Figure 8(b), but there is a difference in optical path length between the two. As a result, a shift in the central positions of wave-coupled states 406 and 408 occurs between Figure 8(b) and Figure 8(c).

[0101] Figure 8(d) shows the situation in which both wave strings 406 and 408 are synthesized or combined 410 at the photosynthesis site 220 to form a predetermined light 230. If the difference in optical path length between the two is greater than the coherence distance shown in Equation 1, the wave strings 406 and 408, which are in a phase-asynchronous relationship 402 with respect to each other, are combined and an ensemble average effect of intensities 420 occurs. Consequently, an averaging effect occurs between the optical noise generated in the first light 202 and the optical noise generated in the second light 204.

[0102] Light with a wide wavelength range (wavelength width "Δλ") propagating through space is called panchromatic light. Conversely, light with a narrow wavelength range is called monochromatic light. Although there are differences in the magnitude of the wavelength width "Δλ", both types of light have a specific wavelength width "Δλ", so the coherence distance "ΔL0" expressed by Equation 1 can be defined. Therefore, the above-mentioned optical noise averaging effect can be obtained with both panchromatic light and monochromatic light.

[0103] As a result of this averaging effect, among the optical characteristics 102 required (desired) for each optical application field shown in Figure 2, not only "improvement in detection accuracy (optical S / N ratio)" and "improvement in measurement accuracy (optical S / N ratio)" but also "improvement in resistance to optical disturbances" can be achieved.

[0104] As explained above, manipulating / controlling the phase-locking characteristics can reduce optical noise. However, in this embodiment, as shown in Figure 4, it is possible to provide the optical characteristics (Figure 2) required (desired) for each optical application field by manipulating / controlling the light intensity distribution and phase characteristics (wavefront characteristics). Furthermore, in this embodiment, the "manipulation / control of phase-locking characteristics" and the "manipulation / control of phase characteristics (wavefront characteristics)" may be combined.

[0105] As shown in Figure 4, a diffuser plate is one of the 270 specific examples of optical property conversion elements that can realize the manipulation / control of phase characteristics (wavefront characteristics). Figure 9 shows experimental results regarding the optical noise reduction effect when using a diffuser plate 488. In the experiment to obtain Figure 9, an optical noise was artificially generated by placing a diffuser plate with an average roughness "Ra" of 2.08 μm in the optical path. The spectral characteristics were measured using a spectrometer placed in the measurement unit 8, and the relative standard deviation value (value normalized by the average value of spectral detection) of the amount of optical noise generated in the measurement wavelength range of 1.45 μm to 1.65 μm was calculated. The vertical axis of Figure 9 represents the relative standard deviation value corresponding to the amount of optical noise.

[0106] Figure 9(a) shows the optical noise characteristics when no diffuser plate is placed. Figure 9(b) shows the optical noise characteristics when a diffuser plate 488 with an average roughness "Ra" of 1.51 μm is placed inside the light source unit 2 (for example, at the placement position of the diffuser plate 488 in Figure 16). As shown in the "Conventional Technology" column on the left end of Figures 9(a) and 9(b), simply inserting the diffuser plate 488 alone (Figure 9(b)) reduces optical noise compared to the conventional method (Figure 9(a)).

[0107] In Figure 9, the region where the number of optical path divisions (value of PuwS_M) is 2 or more shows the effect of using a combination of operation / control of phase-locking characteristics and operation / control of phase characteristics (wavefront characteristics). Figure 9(a) in this region shows the reduction of optical noise when only operation / control of phase-locking characteristics is performed without using the diffuser plate 488 (i.e., when only an optical path length conversion element is placed in the optical path). In Figure 9(a) in this region, it can be seen that the amount of optical noise decreases as the number of region divisions (number of wavefront divisions or number of optical path divisions, value of PuwS_M) that cause optical path length differences increases. Furthermore, in Figure 9(b), obtained by using the diffuser plate 488 which performs operation / control of phase characteristics (wavefront characteristics), the amount of optical noise is reduced even more than in Figure 9(a).

[0108] Figure 10 shows an example of an expansion plate, illustrating how optical noise is reduced by manipulating / controlling the phase characteristics (wavefront characteristics). When one initial wave stream 400 passes through the diffuser plate 488, it is split into multiple wave streams 430-0, -1, and -2 with different phases (the detailed principle will be described later). Furthermore, the optical noise generated by wave link 430-0 as it passes through the optical path interferes with the optical noise generated by wave link 430-1 and wave link 430-2 as they pass through the optical path. As a result, the amount of optical noise is expected to be reduced.

[0109] As shown in Figure 4, specific examples of optical property conversion elements that manipulate / control phase characteristics (wavefront characteristics) include, in addition to diffusers, diffraction gratings / holograms, various aberration generating elements, and stepped plates. These optical property conversion elements, other than diffusers, also cause the aforementioned wave splitting and reduce the amount of optical noise.

[0110] Various optical characteristic conversion elements that manipulate / control the phase characteristics (wavefront characteristics) set the wave splitting of the initial wave stream 400 and the phase shift amounts between the divided wave streams 430-0, -1, and -2. Various operation / control parameters 280 that control the optical characteristics of the resulting predetermined light 230 are described together in Figure 4.

[0111] However, simply controlling the value of the operation / control parameter 280 shown in Figure 4 limits the range of optical characteristics of the predetermined light 230 that can be controlled. Therefore, in this embodiment, as shown in Figure 3, the optical characteristic conversion element 210 is divided into multiple regions 212 to 216, and different values ​​of the operation / control parameter 280 can be set for each region 212 to 216. As a result, the range of optical characteristics of the predetermined light 230 that can be controlled by a single optical characteristic conversion element 210 is greatly expanded. Consequently, using an optical characteristic conversion element 210 with a structure divided into multiple regions 212 to 216 greatly improves the ease of realizing the required (desired) optical characteristics for each optical application field shown in Figure 2.

[0112] Using an example in Figure 10, we will explain a specific example of the effect of an optical property conversion element 210 having a structure divided into multiple regions 212 to 216. In the first light 202 that has passed through the first region 212 within the optical property conversion element 210, we consider that three wave chains 430-0, -1, and -2 with different phases, as shown in Figures 10(d), 10(f), and 10(h), are generated. Furthermore, the value of the operation / control parameter 280 is changed between the first region 212 and the second region 214. Therefore, the phases of the three wave chains with different phases that are separated and generated in the second light 204 that has passed through the second region 214 are different from the phases of the wave chains 430-0, -1, and -2 in the first light 202. As a result of synthesizing all the wave chains at the photosynthesis site 220, the predetermined light 230 contains six wave chains with different phases from each other (a total of nine wave chains if we consider up to the third light 206 that has passed through the third region 216). As the number of wave chains with different phases within the predetermined light 230 increases, the effect of reducing optical noise is further enhanced.

[0113] As shown in the experimental results in Figure 9, combining the manipulation / control of phase characteristics (wavefront characteristics) with the manipulation / control of phase synchronization characteristics increases the averaging effect between optical noises. Furthermore, this combination also makes it possible to reduce the coherence of the predetermined light 230. The basic concepts of this technical ingenuity are explained below.

[0114] For example, if an interference path exists in the optical path of a single-wavelength, same-phase beam, interference fringes with periodically changing intensity will appear in the cross-section image and spectral characteristics of that beam. Incidentally, if the above interference path is properly set, interference fringes can be observed not only in the far region 180 but also in the focusing / imaging plane and its vicinity 170.

[0115] In the world of optics, visibility (SV) is defined as the difference between the maximum and minimum intensity within an interference fringe divided by the average intensity. Specifically, it is defined in the middle part of equation 13. This visibility (SV) value is often used to evaluate the degree of coherence of light.

[0116] If "operation / control of phase characteristics (wavefront characteristics)" is performed along the optical path before the interference generation path described above, a phenomenon of mixing of light of the same wavelength but with different phases occurs within the predetermined light 230. Then, as shown in equation 22 described later, the position of light intensity within the interference fringes shifts in accordance with this change in phase amount. Furthermore, by adding "operation / control of phase synchronization characteristics," the amount of mixing of light with different phases increases (i.e., the number of different phase light elements mixed within the predetermined light 230 increases).

[0117] When multiple interference fringes that are offset from each other overlap, the light intensity differences between the individual interference fringes cancel each other out, and the overall visibility value decreases. This decrease in visibility value is evaluated as a decrease in the coherence of the predetermined light 230.

[0118] In particular, if the "operation / control of phase synchronization characteristics" is performed first according to the direction of light propagation 348, followed by the "operation / control of phase characteristics (wavefront characteristics)," and then the photosynthesis site 220 is positioned, the effects of the aforementioned optical action are improved (specific examples of this positioning will be described later in Figures 16 and 17A / B). In some cases, the light 202-206 whose "phase characteristics (wavefront characteristics) have been operated / controlled" may have some divergence (the directivity in which all light propagation directions coincide is slightly reduced). Therefore, performing the "operation / control of phase synchronization characteristics followed by the operation / control of phase characteristics (wavefront characteristics)" while the directivity of the light is high improves the optical noise reduction effect and coherence reduction effect.

[0119] As described above, reducing coherence leads to the achievement of several desirable optical properties for each optical application field, as shown in Figure 2, including "reduction of speckle noise," "reduction of laser mode hopping noise," "improvement of uniformity of irradiated light intensity," "improvement of luminescence stability," and "improvement of illuminance uniformity." This effect is common to both all-color and single-wavelength light.

[0120] Even when reducing the coherence of a predetermined light 230 by combining the manipulation / control of phase characteristics (wavefront characteristics) and the manipulation / control of phase synchronization characteristics, the coherence reduction effect is further improved if the optical characteristic conversion element 210 that performs the manipulation / control of phase characteristics (wavefront characteristics) is composed of multiple regions 212 to 216 in which the values ​​of the manipulation / control parameters 280 are set to be different from each other. In other words, the individual manipulation / control parameters 280 within the multiple regions 212 to 216 can be flexibly set to best suit the required (desired) optical characteristics content 102 for each optical application field shown in Figure 2.

[0121] The basic concepts of the technical innovations in this embodiment described above will be explained theoretically and concretely below. For the sake of simplicity, the explanation below will be given as an example of single-wavelength light with a central wavelength of "λ0" and a wavelength range of "Δλ". However, it is not limited to this, and the following explanation can also be applied to, for example, all-color light or white light. Here, the individual wavelength characteristics obtained after spectrally separating all-color light or white light with a spectrometer correspond to the explanation below. Specifically, the detection wavelength of each detection cell in the spectrometer corresponds to "λ0", and the wavelength resolution of the spectrometer corresponds to "Δλ".

[0122] As mentioned earlier, we will theoretically analyze the interference generation path, specifically using "interference between straight-traveling light and reflected light from the front and back surfaces of parallel transparent plates or sheets" as a concrete example. Next, we will generalize the form of this interference generation path and quantitatively explain the optical noise reduction phenomenon when "operation / control of phase synchronization characteristics" is performed when optical noise is generated.

[0123] Next, the "phase separation model" of light passing through the diffuser plate will be explained, and the phenomenon of decreased visibility value when "operation / control of phase-locking characteristics" and "operation / control of phase characteristics (wavefront characteristics)" are combined will be explained quantitatively.

[0124] Let "n" represent the refractive index of a transparent plate or sheet with parallel front and back surfaces, and "d" represent the thickness of the front and back surfaces. "d0 + δd" represents the thickness of the front and back surfaces. The difference in arrival time between in-phase locations between the straight-traveling light (j=0) and the light reflected once from each surface (j=1) is "τ". j "teeth,

[0125]

number

[0126] Between the wavelength width "Δλ" of the central wavelength "λ0" and the corresponding frequency width "Δν",

[0127]

number

[0128]

number

[0129]

number

[0130] The amplitude characteristics of the composite light (predetermined light 230) obtained when initial light 200 having a central frequency "ν0" and frequency width "Δν" passes through a transparent plate or transparent sheet with a thickness range "Δd" are as follows:

[0131]

number

[0132]

number

[0133]

number

[0134]

number

[0135]

number

[0136]

number

[0137] The cosine function shown in the third term on the right-hand side of Equation 11 exhibits a "periodic change in light intensity" corresponding to the change in wavelength "λ0". Therefore, this cosine function contributes to the generation of interference fringe patterns in the spectral characteristics.

[0138] And in response to the above-mentioned "periodic change in light intensity," the visibility "SV" mentioned earlier is

[0139]

number

[0140]

number

[0141] Up to this point, we have analyzed the phenomenon of interference fringe generation when parallel transparent plates or sheets are placed as interference paths. Next, we will extend the concept of this analysis result to set up an optical noise generation model. That is, we will assume that some kind of interference path occurs in the optical path of a single-wavelength light beam whose phases are synchronized (matched). We will then consider the superposition of multiple types of interference fringes that appear in the cross-sectional image or spectral characteristics of the light beam due to the optical interference that occurs here as the cause of optical noise, and construct an analytical model.

[0142] In this case, instead of a transparent plate or sheet with a predetermined thickness range "Δd", we assume a minute optical path length difference change range "(n-1)Δd" that occurs within a specific interference generation path. Therefore, as the mathematical model of the source of optical noise generation, instead of Equation 10

[0143]

number

[0144] In the optical noise generation model assumed here, A) An initial light 200 with an amplitude value of "1" is incident into the interference generation path. B) At the j-th optical noise generation location, the amplitude "E j "Optical noise generation light is generated C) As a result of the initial light 200 traveling through the interference path, the amplitude is “E0 = 1 - SUM(E j )” D) Light with amplitude attenuated to "E0" and amplitude "E jOptical noise is generated by interference between each optical noise-generating light. Let us assume the above [C],

[0145]

number

[0146] The intensity of light that has passed through the m-th region within the optical path length conversion element (optical characteristic conversion element 210 that performs operation / control of phase-locking characteristics) is “ Rm It is represented as ">". This “ Rm The characteristic formula for ">" is, In equation 11, replace “Dp0” with “E0D0”, and further replace “R 2 Dp1" to "E j D j Replace with " and "2d0" with "χ mj It is given by the equation obtained by substituting "".

[0147] Since the wave strings 406 and 408 that have individually passed through each region within the optical path length conversion element are in a phase-asynchronous relationship 402 with respect to each other, the characteristic expression of the predetermined light 230 after synthesis at the photosynthesis site 220 is given by the simple sum of each intensity characteristic. If "M" is the number of regions divided within the optical path length conversion element (wavefront division number or optical path division number, value of PuwS_M), then the characteristic expression of the predetermined light 230 is

[0148]

number

[0149] In equation 16, as the number of regions "M" increases, in the limit state

[0150]

number

[0151]

number

[0152] Building upon the findings above, we will now analyze the operation of the optical property conversion element 210, which manipulates / controls the phase characteristics (wavefront characteristics) of the diffuser plate. Figure 10(b) shows the surface roughness distribution characteristics of the diffuser plate. According to statistical theory, this surface roughness distribution characteristic is known to be similar to a "Gaussian distribution". Figure 10(b) can be approximated as a combination of three stacked rectangular distributions, Figures 10(c), (e), and (g). What is important here is that, unlike a perfectly symmetrical Gaussian distribution, the actual surface roughness distribution characteristics of the diffuser plate deviate from perfect symmetry. Taking the center position of the top rectangular distribution shown in Figure 10(c) as a reference, the amount of deviation of the center position of the middle rectangular distribution shown in Figure 10(e) is expressed as "χ1". Similarly, the amount of deviation of the center position of the bottom rectangular distribution shown in Figure 10(g) is expressed as "χ2". Then, the initial wave string 400 with an amplitude value of "1" in Figure 10(a) passes through the "lth stage" (l≧0) rectangular distribution from the top and its amplitude value is "E l D l It approximates ".

[0153] In other words, within the first light 202 that has passed through the first region 212 in the optical characteristic conversion element 210 that manipulates / controls the phase characteristics (wavefront characteristics), there is an amplitude value "E l D l "and phase value "χ l This includes multiple wave strings 430-0 to -2 that have the same properties. Furthermore, if the optical property conversion element 210 in Figure 3 has a structure divided into multiple regions 212 to 216, then the predetermined light 230 generated and synthesized in the photosynthesis site 220 contains even more wave strings.

[0154] The intensity characteristics of this predetermined light 230 are given by “(E0D0)” in equation 16. 2 " to "SUM{(E l D l ) 2 This can be expressed using a formula that has been changed to}. However, in this case, the subscript "m" represents the region number within the optical characteristic conversion element 210 that performs the operation / control of the phase characteristics (wavefront characteristics). Also, the variable "M" represents the total number of areas within the optical characteristic conversion element 210 that performs the operation / control of the phase characteristics (wavefront characteristics).

[0155] In this case as well, the same 'averaging effect' as in equation 17 comes into play, and in extreme conditions...

[0156]

number

[0157] Next, we will explain the operating principle of reducing coherence by combining an optical property conversion element 270 that manipulates / controls the phase characteristics (wavefront characteristics) including a diffuser plate and an optical path length conversion element (optical property conversion element 210 that manipulates / controls the phase synchronization characteristics). For the sake of simplicity, we will explain the case where only the first region 212 is included within the optical property conversion element 210 that manipulates / controls the phase characteristics (wavefront characteristics) of the diffuser plate, etc. However, although we will omit the detailed explanation, if the optical property conversion element 210 that manipulates / controls the phase characteristics (wavefront characteristics) is composed of multiple regions 212 to 216 as shown in Figure 3, the effect of reducing coherence will be further increased.

[0158] Here, we consider the case where light passing through the mth region of an optical path length conversion element divided into "M" regions passes through a diffuser plate (optical characteristic conversion element 210 that manipulates / controls the phase characteristics (wavefront characteristics)) which is uniquely composed of the first region 212. In this case, as shown in Figure 10, after passing through the "lth stage" (l≧0) rectangular distribution from the top, "χ ml A phase difference of "χ" occurs. Even with the same diffuser plate (optical characteristic conversion element 210 that manipulates / controls phase characteristics (wavefront characteristics)), a phase difference "χ" occurs depending on slight changes in each optical path passing through it. ml This changes. Thus, the phase characteristics change sensitively depending on the difference in the optical path.

[0159] In contrast, the amplitude change due to differences in the optical path is considered to be very small. In other words, the amplitude value of the initial wave frenzy 400 with an amplitude value of "1 / √M" in Figure 10(a) after passing through the rectangular distribution of the "lth stage" does not depend on the number of the passing region within the optical path length conversion element and is "E l D l It can be approximated as / √M''.

[0160] The amplitude characteristics of each individual light beam that has passed through the diffuser plate described above, after passing through the 'transparent plate or sheet with parallel front and back surfaces' described by equation 8, are:

[0161]

number

[0162] Next, the spectral characteristics of the individual light particles represented by equation 20 after they have been synthesized into a predetermined light 230 at the photosynthesis site 220 are calculated. Spectral characteristics are generally expressed as the ratio of the detected spectral intensity characteristics to the spectral intensity characteristics of a reference light. Here, the spectral intensity characteristics of the predetermined light 230, after passing through the optical path length conversion element, diffuser, and photosynthesis site 220, are treated as the spectral intensity characteristics of the reference light. The spectral intensity characteristics of the reference light in this case can be approximated by equation 19.

[0163] The spectral intensity characteristics obtained when a transparent plate or sheet with parallel front and back surfaces is inserted in the optical path of this reference light are treated as the "detected spectral intensity characteristics." The spectral characteristics calculated here are:

[0164]

number

[0165]

number

[0166] Then, the interference fringe characteristics (the original visibility "SVorg(λ0)" represented by Equation 13) obtained by the interference of directional light traveling through parallel transparent plates or sheets and reflected light from the front and back surfaces overlap with the second term group on the right-hand side of Equation 22. In particular, when the value of Equation 19 is small, the value of the second term group on the right-hand side of Equation 22 increases overall. As a result, an "averaging effect" comes into play, and the overall visibility value "SVdiff(λ0)" decreases.

[0167] The relative coherence "SVR(λ0)" is defined below as the ratio of the visibility "SVdiff(λ0)" obtained when using the optical property conversion element 210 to the original visibility "SVorg(λ0)" represented by equation 13.

[0168]

number

[0169] Figure 11 shows the results of an experimental demonstration regarding the effect of reducing the coherence of a predetermined light 230 when using the optical property conversion element 210 used in this embodiment. Figure 11(a) shows the change in relative coherence when only diffusers 488 with different average roughness "Ra" are placed inside the light source unit 2 (the position where the diffuser plate 488 is placed in Figure 16). As the average roughness of the diffuser plate 488 increases, the relative coherence decreases, demonstrating the effect of the optical property conversion element 210, which manipulates / controls the phase characteristics (wavefront characteristics).

[0170] Figure 11(b) shows the change in relative coherence when an optical characteristic conversion element 210 that manipulates / controls phase-locking characteristics is added (at the same position as the wavefront multi-segment optical path length conversion element 360 in Figure 16). It can be seen that when an optical characteristic conversion element 210 that manipulates / controls phase-locking characteristics is used in combination with an optical characteristic conversion element 210 that manipulates / controls phase characteristics (wavefront characteristics), the effect of reducing the coherence of the predetermined light 230 increases.

[0171] The theoretical analysis and experimental demonstration of the effects described above use the characteristics when the diffuser plate 488 is used as an example. However, similar effects can be obtained not only with the diffuser plate 488, but also with other optical property conversion elements 210 that manipulate / control phase characteristics (wavefront characteristics).

[0172] Chapter 4 Characterization Method in This Embodiment Chapter 3 explained that the predetermined light 230 formed in this embodiment exhibits reduced optical noise or coherence compared to the initial light 200. As a result, the predetermined light 230 has the optical characteristics required (desired) for each optical application field shown in Figure 2, compared to the conventional initial light 200.

[0173] This chapter describes a characteristic evaluation method for determining whether the predetermined light 230 formed in this embodiment has the optical properties required (desired) for each optical application field shown in Figure 2. That is, if at least one of the methods of this embodiment is implemented (adopted) and the evaluation result using the characteristic evaluation method described below satisfies the predetermined determination conditions, it can be evaluated as "conforming to this embodiment."

[0174] The predetermined light 230 formed in this embodiment is basically, A) Spectroscopic characteristics or B) Captured Image Characteristics The evaluation is performed using the following method. Furthermore, the light obtained when at least one of the methods of this embodiment is not performed is defined as "initial light 200," and the light obtained by performing at least one of the methods of this embodiment is defined as "predetermined light 230." The optical properties of "initial light 200" and "predetermined light 230" are measured using the same characteristic evaluation method, and the measurement results are compared to evaluate whether there are any differences between the two.

[0175] The evaluation method for reducing the amount of optical noise is the method shown in Figure 9. That is, an optical system consisting of a light source unit 2 and a measurement unit 8 as shown in Figure 1 may be constructed, and the amount of optical noise generated within that optical system may be evaluated. Here, the 'initial light 200' and the 'predetermined light 230' are switched depending on whether or not at least one of the techniques described in this embodiment is adopted within the light source unit 2 (including the optical characteristic conversion block 390 placed in the light propagation path 6). Alternatively, as performed during the data measurement in Figure 9, the optical characteristics when 'intentionally generating optical noise' is introduced by inserting a phase characteristic (wavefront characteristic) manipulation / control element such as a diffuser plate 488 or a diffraction grating / hologram into a part of the optical system (for example, within the light propagation path 6) may be compared.

[0176] As an evaluation value for optical properties, the "relative standard deviation" can be used, as in Figure 9. The procedure for calculating this "relative standard deviation" is explained below. 1. The data obtained from either "A) Spectral Characteristics" or "B) Imaging Image Characteristics" above is averaged to calculate the "Average Value Characteristics". 2. The difference between the above "A) Spectral characteristics" or "B) Image characteristics" and the above "Average value characteristics" is calculated as the "Individual displacement amount". 3. The ratio of the above-mentioned "individual displacement amounts" to the above-mentioned "average value characteristics" (i.e., the value obtained by dividing the "individual displacement amounts" by the "average value characteristics") is defined as the "relative displacement amount." 4. The distribution of 'relative displacement' is statistically analyzed (by performing 'normalization' to approximate a normal distribution), The standard deviation (of that approximated normal distribution) is calculated and referred to as the 'relative standard deviation'.

[0177] The "Prior Art" in FIG. 9(a) shows the characteristics of the "Initial Light 200". And the other data shows the optical characteristics obtained from the "Predetermined Light 230" obtained by adopting the individual technologies described in this embodiment. Comparing FIG. 9(a) and FIG. 9(b) in the "Prior Art", the "Relative Standard Deviation Value" obtained from the "Predetermined Light 230" is reduced by about 20% compared to the "Relative Standard Deviation Value" obtained from the "Initial Light 200". Therefore, by comparing the "Relative Standard Deviation Value" obtained from the "Initial Light 200" with the "Relative Standard Deviation Value" obtained from the "Predetermined Light 230", it is regarded as having an effect in a state where it has decreased by 20% or more (when this embodiment is implemented).

[0178] On the other hand, in the case where the "Prior Art" in FIG. 9(a) and the number of optical path divisions is "2", it only decreases by about 5%. Therefore, when judged strictly, it may also be regarded as having an effect in a state where it has decreased by 5% or more (when this embodiment is implemented).

[0179] FIG. 9 shows the comparison data of "A) Spectral Characteristics". However, it is not limited to this, and it may also be evaluated using the "B) Imaging Image Characteristics" caused by the optical noise appearing in the captured image detected by the imaging device 300. In this case as well, the "Relative Standard Deviation Value" is calculated by the same method as above, it is regarded as having an effect in a state where it has decreased by 20% or more (when this embodiment is implemented), or judged strictly it may also be regarded as having an effect in a state where it has decreased by 5% or more (when this embodiment is implemented).

[0180] Calculating and comparing the above "Relative Standard Deviation Value" can improve the evaluation accuracy the most. However, doing statistical analysis (normalization of the "Relative Displacement Amount Distribution") for this purpose is burdensome. Therefore, instead of calculating the exact "Relative Standard Deviation Value", examine the "Amplitude Value of the Noise Component" that is considered to be caused by optical noise in either "A) Spectral Characteristics" or "B) Imaging Image Characteristics", compare the data obtained from the "Initial Light 200" with the data obtained from the "Predetermined Light 230", and evaluate the effect. In this case, compare the "Amplitude Value" within either "A) Spectral Characteristics" or "B) Imaging Image Characteristics", "The effect is observed when the reduction is 20% or more (by implementing this embodiment)," or, strictly speaking, It may be considered that "the effect is present (the embodiment has been implemented) when the reduction is 5% or more."

[0181] Figure 12 shows comparative data of speckle noise generated based on coherence. Figure 12(a) shows the intensity distribution of a cross-section of an image obtained from a non-mirror surface (a general light-scattering surface) when "initial light 200" in a parallel light beam state is shone onto that non-mirror surface. Here, any surface that scatters light, such as ordinary paper, a wall, or skin, can be used as the non-mirror surface. Similarly, Figure 12(b) shows the intensity distribution of a cross-section of an image obtained from a non-mirror surface when "predetermined light 230" is shone onto that non-mirror surface.

[0182] In the world of laser interferometry, an index called speckle contrast is used to evaluate this coherence. Here, the same definition formula as the "relative standard deviation" mentioned above is used for speckle contrast. That is, "Ia(x)" in Figure 12 represents the "mean value characteristic" mentioned above, and "dI(x)" in Figure 12 corresponds to the "individual displacement amount" mentioned above.

[0183] When using "Initial Light 200," the speckle contrast value obtained in Figure 12(a) was "9.85%." On the other hand, when using "Prescribed Light 230," the speckle contrast value obtained in Figure 12(b) was "6.39%." Therefore, it can be seen that using "Prescribed Light 230" reduces the speckle contrast value by approximately 40%. After considering the above data in addition to the optical noise reduction results mentioned above, we will set the criteria for judging the effect with a small margin. That is, by comparing the speckle contrast values, "The effect is observed when the reduction is 20% or more (by implementing this embodiment)," or, strictly speaking, "An effect is considered to have been achieved (implemented in this embodiment) when the reduction is 5% or more."

[0184] The measurement data shown in Figure 12 is data measured as “B] Image Characteristics”. However, optical characteristics may also be measured in the form of “A] Spectral Characteristics”. In this case, “Initial Light 200” or “Determined Light 230” in a parallel light beam state may be irradiated onto a non-mirrored surface (a general light scattering surface), and the speckle contrast value may be calculated in a similar manner from the distribution of “A] Spectral Characteristics” obtained from the non-mirrored surface.

[0185] Furthermore, regarding the evaluation of coherence, calculating and comparing the speckle contrast as described above yields the highest evaluation accuracy. However, performing statistical analysis (normalization of the "relative displacement distribution") for this purpose is burdensome. Therefore, instead of calculating the exact speckle contrast, one can examine the "amplitude value of the noise component" that is thought to be caused by speckle noise within "A) Spectral characteristics" or "B) Image characteristics," and evaluate the effect by comparing the data obtained from "initial light 200" with the data obtained from "predetermined light 230." In this case, the "amplitude value" within "A) Spectral characteristics" or "B) Image characteristics" is compared, "The effect is observed when the reduction is 20% or more (by implementing this embodiment)," or, strictly speaking, It may be considered that "the effect is present (the embodiment has been implemented) when the reduction is 5% or more."

[0186] Up to this point, the method for evaluating / determining the optical properties of the "predetermined light 230" has been explained. Next, the method for evaluating and determining the optical properties of each optical property conversion element 210 will be explained. That is, an optical system incorporating an optical property conversion element 210 whose measurement results using the evaluation method shown below satisfy the following determination conditions is considered to be using at least a part of this embodiment.

[0187] Figure 13 shows an example of the RMS value of wavefront aberration obtained from the measurement results. Figure 13 shows the RMS value of wavefront aberration of light that has passed through a wavefront multi-segment optical path length conversion element 360 (see Figure 16) which is divided into eight segments in the angular direction (without radial division). As a specific evaluation / measurement method, the wavefront characteristics of light transmitted or reflected by the optical characteristic conversion element 210 are measured using a transmission or reflection type interferometer, and its RMS value is calculated.

[0188] As explained using Figure 6D, the wavefront accuracy value of the light transmitted or reflected by the optical property conversion element 210 is "This embodiment is implemented when the value is 0.5λ or more and 100λ or less," or more precisely, This embodiment is considered to be implemented when the value is 0.3λ or greater and 1000λ or less. Here, we set the wavelength "λ" to "400nm".

[0189] As already explained using Figures 6A to 6C, when using the optical property conversion element 210 that manipulates / controls the phase characteristics (wavefront characteristics), the divergence angle of the light passing through it becomes important. Figure 14 shows the measurement / evaluation method and judgment criteria for the optical property conversion element 210 with respect to the divergence angle of light. When the initial light 200 passes through the first region 212, it has a divergence angle of "θ1" in the first optical path 222. On the other hand, when the initial light 200 passes through the second region 214, it has a divergence angle of "θ2" in the second optical path 222. The divergence angle "θ" is determined from the full width at half maximum (FWHM) 198 of the light intensity distribution projected onto the screen 326, which is positioned at a predetermined distance from the optical property conversion element 210. Here, a mask pack 328 that partially blocks light is placed directly in front of the optical property conversion element 210, and by comparing the FWHM 198 when no light is blocked with the FWHM 198 when only the first region 212 is blocked and the FWHM 198 when only the second region 214 is blocked, the respective divergence angles "θ1" and "θ2" can be determined. In this embodiment, the relationship between the above divergence angles "θ1" and "θ2" is as follows: "This embodiment is implemented when 1.2 ≤ θ1 / θ2 ≤ 1000," or more precisely, This embodiment is considered to be implemented when 1.5 ≤ θ1 / θ2 ≤ 100.

[0190] Figure 15 shows an example of spectral characteristic measurement results for light transmitted through an optical property conversion element 210 that manipulates / controls phase characteristics (wavefront characteristics). Figure 15(a) shows the spectral characteristic measurement results for an optical property conversion element 210 composed only of the first region 212. As the measurement wavelength increases, the light transmission intensity increases rapidly. On the other hand, Figure 15(b) shows the spectral characteristic measurement results for an optical property conversion element 210 composed of a combination of the first region 212 and the second region 214, which have different average roughness values ​​"Ra". A significant difference in spectral characteristics is observed compared to Figure 15(a).

[0191] Here, the data in Figure 15(a) is considered to be the data obtained from "initial light 200". Then, the data in Figure 15(b) is considered to be the data obtained from "predetermined light 230", and the characteristics of the two are compared. The difference in the effects of the two is evaluated by the relative change in light transmission intensity "Δ(λ)" at an arbitrary wavelength, with the data in Figure 15(a) as the reference. Following the evaluation method described above, the value obtained by dividing the "absolute change in light transmission intensity" by the "light transmission intensity obtained from initial light 200" at the same wavelength is defined as the "relative change in light transmission intensity "Δ(λ)". And in this relative change in light transmission intensity "Δ(λ)", "The effect is observed when there is a change of 20% or more (by implementing this embodiment)," or strictly judged to be effective. "An effect is considered to have been achieved (implemented by this embodiment) when the change is 5% or more."

[0192] Chapter 5 Specific Examples of Light Sources and Optical Characteristic Conversion Blocks Chapter 2 outlined the basic optical operations in this embodiment. Chapter 2 describes specific examples within the optical characteristic conversion block 390, which is included in the light source unit 2 or, more broadly, in a part of the light source unit 2, by combining the individual elemental technologies described in Chapter 2.

[0193] Figure 16 shows a specific embodiment of the light source unit 2 when an incandescent light source is used as the light source. For example, the surface of a heat-generating lamp 472 such as a halogen lamp or a mercury lamp becomes hot. On the other hand, the optical system that produces the effects described in Chapter 3 is sensitive to the ingress of dust, dirt, and other contaminants in the optical path. In the structural overview shown in Figure 16(b), the light-emitting unit 470 housing the incandescent lamp 472 and the optical characteristics control unit 480 are mechanically separated. An optical fiber 330 is connected to the outlet of this optical characteristics control unit 480. By using the optical fiber 330, which has excellent mechanical flexibility, the light output from the optical characteristics control unit 480 can be guided to any desired location. Furthermore, as shown in Figures 16(a) and 16(c), an insulating plate 476 is placed between the light-emitting unit 470 and the optical characteristics control unit 480 to block heat conduction between them. In addition, the area around the optical characteristics control unit 480 is covered to block the flow of air from the outside. By adopting this structure, dust, dirt, and other contaminants can be prevented from entering the optical properties control unit 480. Furthermore, the heat conduction blockage by the heat insulating plate 476 reduces thermal deformation inside the optical properties control unit 480 caused by temperature changes.

[0194] Incidentally, the light emitted from the incandescent lamp 472 passes through the optical properties control unit 480. For this reason, a light-transmitting medium is placed in a part of the heat-insulating plate 476. The light emitted from the incandescent lamp 472 passes through this light-transmitting medium. On the other hand, this light-transmitting medium placed in the heat-insulating plate 476 blocks the flow of air and heat from inside the light-emitting unit 470 to inside the optical properties control unit 480. A transparent resin (plastic) may be used as the material for this light-transmitting medium. However, transparent resins have a high light absorption rate in the near-infrared region (for example, wavelengths of 1.6 μm or more). Therefore, when using the near-infrared light obtained from this light source unit 2, it is desirable to use transparent glass or quartz glass as the material for the light-transmitting medium.

[0195] A parallel plate can be used as the shape of this light-transmitting medium. In Figure 16, an imaging lens 312 is used in the light-transmitting medium, which also serves to block airflow and heat flow, as well as to concentrate the light emitted from the lamp 472. By combining various functions in this way with the imaging lens 312, it is possible to simplify and reduce the cost of the light source unit 2 itself.

[0196] Furthermore, an imaging lens 312 is disposed at a position deeper with respect to the surrounding heat insulating plate 476. This prevents an operator from accidentally contacting the imaging lens 312 when replacing the lamp 472.

[0197] In FIG. 16, as light transmissive media disposed at the boundary between the light emitting unit 470 and the optical characteristic control unit 480, ND filters (neutral density filters) 492, 494, band-pass filters or high-pass filters 496, and band-pass filters or low-pass filters 498 are disposed.

[0198] The amount of light and the spectral characteristics of the radiation light from the incandescent lamp 472 change with the filament temperature in the lamp 472. Therefore, from immediately after the start of lighting of this incandescent lamp 472 until the filament temperature stabilizes, the amount of light and the spectral characteristics of the radiation light change with the passage of time. To stabilize the light emission amount of this radiation light, the light emission amounts are detected by the photodetectors 482-1 and 482-2, and the current value supplied to the incandescent lamp 472 is controlled.

[0199] Particularly in the case of the incandescent lamp 472, it has spectral characteristics in which the long wavelength intensity increases as the filament temperature rises. Therefore, for example, when measuring using both visible light and near infrared light emitted from this light source unit 2, it is desirable to simultaneously detect the light emission amounts in both the wavelength range of visible light and the wavelength range of near infrared light and perform light amount control. Therefore, a photodetector 482-1 that detects only the near infrared light that has passed through the band-pass filter or high-pass filter 496 and a photodetector 482-2 that detects only the visible light that has passed through the band-pass filter or low-pass filter 498 are disposed. Also, the detection sensitivities of the photodetector 482-1 for near infrared light and the photodetector 482-2 for visible light are different from each other. For correcting this detection sensitivity, ND filters 492, 494 are individually disposed.

[0200] Within the light-emitting section 470, a concave mirror 474 is installed on the back of the lamp 472. The light emitted towards the back of the lamp 472 is reflected by the concave mirror 474, passes through the gap between the filaments inside the lamp 472, and then heads towards the imaging lens 312. In this way, the light emitted towards the back of the lamp 472 is also effectively utilized, improving the efficiency of light utilization from the light source section 2.

[0201] Inside the light-emitting section 470, two fans 478-1 and 478-2 are positioned to create an artificial airflow 442. Specifically, the upper fan 478-1 draws in outside air, and the rear fan 478-2 expels the air inside the light-emitting section 470 to the outside. In particular, a portion of the airflow 442 directly hits the lamp 472, improving the heat dissipation effect of the lamp 472. On the other hand, the airflow 442 is positioned so that it does not directly hit the imaging lens 312 or the ND filters 402 and 494. This prevents dust and debris trapped inside the airflow 442 from adhering to the imaging lens 312 or the ND filters 402 and 494.

[0202] Furthermore, louver windows 440-1 and 440-2 are installed on the outside of each fan 478-1 and 478-2 to prevent radiant light from leaking out through the intake of the upper fan 478-1 and the exhaust of the rear fan 478-2.

[0203] Because the area around the incandescent lamp 472 becomes extremely hot when it is lit, technical ingenuity is required for a stable method of fixing the lamp 472. The lamp fixing part 446, made of a material with excellent heat insulation properties and a low coefficient of thermal expansion, supports the lamp base 473 and fixes the position of the incandescent lamp 472. In particular, the large temperature change between turning the incandescent lamp 472 on and off causes repeated large thermal expansion and contraction of the lamp base 473. To prevent the lamp 472 from shifting due to this repeated thermal expansion and contraction of the lamp base 473, the lamp fixing part 446 itself is given shape elasticity, and a structure is made that allows sliding between the lamp fixing part 446 and the lamp base 473. The lamp fixing part 446 can be finely adjusted by the lamp's fine adjustment mechanism 448 to fine-tune the position of the lamp 472 within the light-emitting part 470.

[0204] The optical characteristics control unit 480 is equipped with an aperture control unit 484, which has a small aperture. The imaging lens 312 projects (images) the imaging pattern of the filament inside the lamp 472 onto the surface of the aperture control unit 484. Only the central part of this imaging pattern passes through the aperture in the aperture control unit 484. In this way, the aperture control unit 484 is provided within the optical characteristics control unit 480 to define the ideal optical path (optical axis) of the light emitted from the lamp 472. That is, light emitted from a path that deviates significantly from the ideal optical path (optical axis) is blocked by the aperture control unit 484. This function of the aperture control unit 484 prevents unnecessary wavefront aberration that occurs along the optical path. As a result, the optical characteristics described in Chapter 3 can be effectively exhibited.

[0205] For example, if the position of the lamp 472 is significantly off from the center position within the light-emitting section 470 without the aperture control unit 484, a large coma aberration will occur as the light emitted from the lamp 472 passes through the imaging lens 312, collimating lens 318, and condensing lens 314. Unnecessary wavefront aberrations such as coma aberration that occur here will cause large variations in the characteristics of the light source section 2 during mass production.

[0206] The filament inside the incandescent lamp 472 is relatively large. Therefore, even if the lamp 472 is positioned near the center of the light-emitting section 470, the light emission position around the filament will be slightly off the ideal optical axis. As a result, the light emitted from around the filament will produce some coma aberration when passing through the imaging lens 312 and the collimating lens 318. Therefore, the aperture control unit 484 blocks the light emitted from around the filament, utilizing only the light with minimal wavefront aberration.

[0207] The synchrotron radiation passing through the aperture control unit 484 is converted into a nearly parallel beam of light after passing through the collimating lens 318. A wavefront multi-segment optical path length conversion element 360, which operates / controls the phase-locking characteristics, is placed in the optical path of this parallel beam. Figure 16(d) shows the wavefront multi-segment optical path length conversion element 360 as viewed from the direction of light propagation. As shown in Figure 16(d), the wavefront multi-segment optical path length conversion element 360 is divided into 12 segments in the angular direction and 4 segments in the radial direction, resulting in 48 segments as already explained in Figure 7B. Two of the 12 boundary lines in the angular direction are set at angles parallel to the horizontal axis 450 and the vertical axis 460, respectively. However, the specific shape of the wavefront multi-segment optical path length conversion element 360 is not limited to this; a 12-segment element as explained in Figure 7C or a 2-segment element as shown in Figure 7A may also be used. Light passing through the wavefront multi-section optical path length conversion element 360 is focused by the focusing lens 314 and enters the optical fiber 330. A diffuser plate 488 is placed along the optical path. Therefore, in the optical characteristic control unit 480 in Figure 16(c), both the wavefront multi-section optical path length conversion element 360 and the diffuser plate 488 are used in combination, so both the phase-locking characteristics and the phase characteristics (wavefront characteristics) are operated / controlled simultaneously.

[0208] Figure 16(e) shows the surface state of the diffuser plate 488. The first light diffusion region 489-1, which has a relatively small average surface roughness "Ra1" and average period "Pa1", constitutes the first region 212. In contrast, the second light diffusion region 489-2, which has a relatively large average surface roughness "Ra2" and average period "Pa2" (satisfying the relationship "Ra2 / Ra1 > 1" and "Pa2 / Pa1 > 1"), constitutes the second region 214. The first light diffusion region 489-1 and the second light diffusion region 489-2 each form a sector with a "central angle of 30 degrees" and are arranged alternately as shown in Figure 16(e).

[0209] In particular, the boundary line between the first light diffusion region 489-1 and the second light diffusion region 489-2 is inclined with respect to the boundary lines that are angularly divided within the multi-segment optical path length conversion element 360. That is, two of the angularly divided boundary lines within the multi-segment optical path length conversion element 360 are parallel to the horizontal axis 450 and the vertical axis 460. In contrast, all the boundary lines between the first light diffusion region 489-1 and the second light diffusion region 489-2 are inclined with respect to the horizontal axis 450 and the vertical axis 460. In other words, the boundary lines between the first light diffusion region 489-1 and the second light diffusion region 489-2 exist within any region within the 48-segmented wavefront multi-segment optical path length conversion element 360.

[0210] Therefore, with respect to light passing through any region within the 48-segmented wavefront multi-segment optical path length conversion element 360, a portion of it will always pass through the first optical diffusion region 489-1, and the remaining portion will pass through the second optical diffusion region 489-2. As a result, the effects described in Chapter 3 are efficiently achieved.

[0211] In particular, the effect described in Chapter 3 is greatly (maximally) exerted when the area of ​​the first light diffusion region 489-1 and the area of ​​the second light diffusion region 489-2 are approximately equal within any region within the 48-divided wavefront multi-segment optical path length conversion element 360. Specifically, the effect is greatest when the angle between the boundary line between the first light diffusion region 489-1 and the second light diffusion region 489-2 with respect to the boundary line that divides the angle within the multi-segment optical path length conversion element 360 is half the angle that divides the angle within the multi-segment optical path length conversion element 360. That is, in Figure 16(e), the angle that divides the angle within the multi-segment optical path length conversion element 360 is 30 degrees, so a great effect can be obtained by arranging the boundary line between the first light diffusion region 489-1 and the second light diffusion region 489-2 so that it is tilted by 15 degrees with respect to the horizontal axis 450 and the vertical axis 460.

[0212] Figures 17A and 17B show an example of the structure within the optical property conversion block 390. Here, instead of configuring the light source 2 independently, the optical property conversion block 390 can be placed in the optical path of the initial light 200 to manipulate / control the optical properties of the initial light 200.

[0213] In the optical property conversion block 390 shown in Figure 17A, the block is placed in the far region 180 of the initial light 200 (for example, in the middle of the optical path of a parallel beam) to generate a predetermined light 230 whose optical properties have been manipulated / controlled. In this optical property conversion block 390, both the phase-locked properties and the phase properties (wavefront properties) are manipulated / controlled simultaneously.

[0214] In other words, the wavefront multi-segment optical path length conversion element 360 is first placed along the direction of propagation of the initial light 200, and the phase-locking characteristics are initially manipulated / controlled. After that, the diffuser plate 488 or diffraction grating or hologram is placed, and the phase characteristics (wavefront characteristics) are manipulated / controlled. Nearly parallel light beams pass through the wavefront multi-segment optical path length conversion element 360. Since the light that has passed through the diffuser plate 488 or diffraction grating or hologram has various propagation directions, photosynthesis takes place in the space immediately after passing through the diffuser plate 488 or diffraction grating or hologram. That is, the space immediately after passing through the diffuser plate 488 or diffraction grating or hologram becomes the photosynthesis site 220. As a result, the predetermined light 230 is obtained. Manipulating / controlling in the above order along the light propagation direction 348 within the optical characteristic conversion block 390 yields the most efficient and significant effect.

[0215] Furthermore, since the optical elements constituting the optical property conversion block 390 shown in Figure 17A consist only of a wavefront multi-section optical path length conversion element 360 and a diffuser plate 488 (or diffraction grating or hologram), there is an advantage in that it is easy to make it thinner and lower in cost.

[0216] With the recent advancements in optical communication technology, all types of light, including not only single-wavelength light such as laser light but also white light and all-color light, are being propagated and utilized via optical fibers (waveguides) 330. The optical property conversion block 390 shown in Figure 17B illustrates a method for manipulating / controlling the optical properties of a predetermined light 230 in a manner that conforms to these technological trends. Specifically, the optical property conversion block 390 shown in Figure 17B is placed in the middle of the optical propagation path 6 via the optical fiber (waveguide) 330.

[0217] The inlet of the optical characteristic conversion block 390 in Figure 17B is connected to the input optical fiber 392, and the outlet of the optical characteristic conversion block 390 is connected to the output optical fiber 398. The initial light 200 that exits from the input optical fiber 392 is converted into a nearly parallel beam by the collimating lens 318. Then, in this far region 180, the nearly parallel beam first passes through the wavefront multi-section optical path length conversion element 360 along the optical propagation direction 348. After passing through this wavefront multi-section optical path length conversion element 360, the phase-locking characteristics are manipulated / controlled.

[0218] The wavefront multi-segment optical path length conversion element 360 may be placed in the nearby region 170, close to the exit surface of the input optical fiber 392. However, considering the slight decrease in light intensity at the interface within the wavefront multi-segment optical path length conversion element 360 (for example, the side of the step in Figure 7C), it is desirable to place the wavefront multi-segment optical path length conversion element 360 in the far region 180. The shape of the wavefront multi-segment optical path length conversion element 360 in Figure 17B is a 48-segment element as already explained in Figure 7B. However, the specific shape of the wavefront multi-segment optical path length conversion element 360 is not limited to this, and a 12-segment element as explained in Figure 7C or a 2-segment element as shown in Figure 7A may also be used. As the light passes through the wavefront multi-division optical path length conversion element 360 along the optical propagation direction 348, it is focused toward the output optical fiber 398 by the focusing lens 314. A diffuser plate 488 is positioned just before the entrance of this output optical fiber 398. A first optical diffusion region 489-1 and a second optical diffusion region 489-2 are formed on the surface of this diffuser plate 488 that faces the entrance of the output optical fiber 398 (the surface closest to the entrance of the output optical fiber 398).

[0219] Then, the first light diffusion region 489-1, in which the average surface roughness "Ra1" and its average period "Pa1" are relatively small, constitutes the first region 212. In contrast, the second light diffusion region 489-2, in which the average surface roughness "Ra2" and its average period "Pa2" are relatively large (satisfying the relationships "Ra2 / Ra1 > 1" and "Pa2 / Pa1 > 1"), constitutes the second region 214.

[0220] In particular, as shown in Figure 16, with respect to light passing through at least one region within the 48-segmented wavefront multi-segment optical path length conversion element 360, a portion of it always passes through the first optical diffusion region 489-1, and the remaining portion passes through the second optical diffusion region 489-2. By arranging the first optical diffusion region 489-1 and the second optical diffusion region 489-2 in this way, the significant effects described in Chapter 3 can be obtained.

[0221] The first light 202, which has passed through the first light diffusion region 489-1 individually, and the second light 204, which has passed through the second light diffusion region 489-2, both propagate within the output optical fiber 398. During the process of light propagation within the output optical fiber 398, the first light 202 and the second light 204 are combined. Therefore, the output optical fiber 398 functions as a photosynthesis site 220. Thus, the phase-locking characteristics and phase characteristics (wavefront characteristics) are sequentially manipulated / controlled and photosynthesized along the optical propagation direction 348 (i.e., after passing through the optical path length conversion element 360 along the optical propagation direction 348, the optical characteristic control element that manipulates / controls the phase characteristics (wavefront characteristics) is passed through the photosynthesis site 220), which allows the effects of Chapter 3 to be achieved most efficiently.

[0222] Alternatively, instead of the diffuser plate 488 in Figure 17B, a diffraction grating or hologram with a fine surface uneven structure may be placed. Furthermore, instead of the diffuser plate 488 in Figure 17B, an uneven structure may be provided on the entrance end face of the output optical fiber. In this case, a first region 212 and a second region 214 may be formed within the entrance end face of the output optical fiber, each having a different average surface roughness value "Ra" and average period "Pa". By providing an uneven structure on the entrance end face of the output optical fiber 298 instead of the diffuser plate 488 in Figure 17B, the number of optical element components can be reduced. As a result, simplification, miniaturization, and cost reduction of the optical system can be achieved.

[0223] Chapter 6: Examples of Unique Imaging Spectroscopy Measurement Combining Imaging and Spectroscopic Characterization Techniques The following describes measurement and service provision examples utilizing the predetermined light 230 generated in the light source unit 2 or the optical property conversion block 390 as explained in the previous chapters. In this embodiment, as already explained in Figure 1, the predetermined light 230 obtained in the light source unit 2 (in a broad sense, including light passing through the optical property conversion block 390) is transmitted via the optical transmission path 6, and this predetermined light 230 is irradiated onto the target object 20 or measurements are performed in the measurement unit 4. The information obtained as a result is then used in conjunction with the various parts 62 to 76 within the application field (various optical application fields) adaptation unit 60. As a result, services are provided to the user.

[0224] As an example of measurement and service provision using the specified light 230, the following will explain a measurement method and service provision method using imaging spectroscopy, which combines imaging technology and spectral characteristic measurement technology. However, it may be applied not only to imaging spectroscopic measurements but also to any measurement or service provision using the specified light 230 as described in the previous chapters.

[0225] Figure 18A shows the spectral characteristics of the absorbance obtained experimentally from glucose dissolved in pure water. The vertical axis of Figure 18A represents the absorbance on a linear scale. The aforementioned predetermined light 230 was used for the measurement in Figure 18A. The majority of the volume of the glucose aqueous solution is occupied by pure water. Therefore, the majority of the spectral characteristics obtained from the glucose aqueous solution consist of the "spectral characteristics of pure water only". For this reason, the data for the "spectral characteristics of pure water only" was measured in advance, and the spectral characteristics of the absorbance of pure glucose dissolved in pure water were extracted by subtracting the "spectral characteristics of pure water only" from the spectral characteristics obtained from the glucose aqueous solution.

[0226] The measurement data in Figure 18A(a) shows that glucose dissolved in pure water exhibits significant light absorption around a wavelength of 1.6 μm. This absorption band is presumed to be due to the vibrational modes of hydrogen atoms individually bonded to carbon atoms within the five-membered ring that constitutes glucose. Although the amount of light absorption is small, a light absorption band corresponding to glucose also appears to exist around a wavelength of 1.24 μm, as shown in Figure 18A(d).

[0227] Note that the measurement data in the wavelength ranges of Figures 18A(b), (c), and (e) are interpreted as measurement errors. Glucose is highly soluble in water. Generally, substances that are highly soluble in water often have local polarity. When such polar substances dissolve in pure water, hydrogen bonding chains are easily generated in the pure water, centered around these polar regions. When these hydrogen bonding chains occur in pure water, the maximum light absorption wavelength value in the "spectral characteristics of pure water only" shifts to the longer wavelength side. As a result, we hypothesize that the absorption changes in Figures 18A(b) and (c) were observed.

[0228] To verify the reliability of the measurement data in Figure 18A, a literature search was conducted on the absorbance characteristics of pure glucose (before dissolution in water). Figure 18B shows the absorbance characteristics of pure glucose. Here, the vertical axis in Figure 18B is displayed on a logarithmic scale as "absorbance". Although there is a difference in the scale display, in both Figure 18A and Figure 18B, the higher the vertical axis, the greater the light absorption. Note that Figure 18B is... From Yukihiro Ozaki and Satoshi Kawada (eds.): Near-Infrared Spectroscopy (2005, Academic Publishing Center), p. 211. I have transcribed the data. In Figure 18B(b), absorption bands can also be observed at wavelengths of 1.6 μm and 1.26 μm. Therefore, by comparing Figure 18A and Figure 18B, the reliability of the measurement data in Figure 18A was confirmed.

[0229] Figures 19(a), 19(b), and 19(c) show comparative measurement data of the relative absorbance of pure water, polyethylene sheet, and silk scarf, respectively. All of these data were measured using the predetermined light 230 described in the previous chapters. There are significant differences in absorbance between pure water, polyethylene sheet, and silk obtained from the actual measurements. In Figure 19, the change in absorbance has been corrected for easier comparison.

[0230] While the majority of living organisms are composed of water, the volume ratio of water in blood vessels is particularly large. Living organisms are primarily composed of three major components: carbohydrates, fats, and proteins. Here, carbohydrates include glucose and its relatives, existing in either single (monosaccharide) or linked (polysaccharide) forms. Furthermore, the atomic arrangement of many atoms within fats is structurally similar to that of polyethylene. In addition, silk is made from proteins. Therefore, broadly speaking, the light absorption properties of the four major components that make up living organisms, including water, are thought to be similar to either Figure 18A or Figure 19.

[0231] Figure 20A shows an example of a measurement environment using imaging spectroscopy. The light source unit 2 emits predetermined light 230 as described in the previous chapter. The predetermined light 230 emitted from the light source unit 2 is reflected by the palm 23 inside the object to be measured 22 and enters the measurement unit 8. Figure 20B shows an example of an image taken inside the measurement unit 8. As shown in Figure 20B, a vascular region 500 exists at a predetermined position inside the palm 23.

[0232] Figure 20C shows an example of a magnified image of the area around the vascular region 500. In this embodiment, the spectral characteristics of each pixel in a one-dimensionally arranged image are measured. The region where these pixels are connected and spectral characteristics can be measured simultaneously is called the simultaneous measurement range 510.

[0233] From the fat-rich region 504 within the simultaneously measurable range 510 in Figure 20C, the spectral characteristics (absorption characteristics) shown in Figure 20C(b) are obtained. Furthermore, from the vascular region 500 and the muscle-rich region 502 within the simultaneously measurable range 510, the spectral characteristics (absorption characteristics) shown in Figures 20C(a) and 20C(c) are obtained. Therefore, from the spectral characteristics (absorption characteristics) obtained for each pixel within the simultaneously measurable range 510, information about the arrangement of, for example, the vascular region 500 can be predicted.

[0234] As shown in Figure 20D compared to Figure 20C, the number of pixels whose spectral characteristics can be measured increases simultaneously, as multiple locations in the simultaneously measurable ranges 510-1 and -2 can be measured at the same time. As a result, the number of pixels for imaging spectroscopy that can be measured at once increases dramatically. Furthermore, if the simultaneously measurable ranges 510-1 and -2 can be moved simultaneously 520, the spectral characteristics of all pixels in the two dimensions can be collected in a very short time. That is, by moving the position of the simultaneously measurable range 510-1 to the position of the simultaneously measurable range 510-2 before the simultaneous movement 520, the spectral characteristics of all pixels can be collected in a short time. In order to enable this measurement, in this embodiment, the optical characteristic conversion element 210, which has already been explained using Figure 5A, is placed inside the measurement unit 4. The spectral characteristic information of all pixels in the two dimensions is called a data cube. In the explanation using up to Figure 20D, spectral characteristic information (data cube) for all pixels in the two dimensions can be measured.

[0235] Figures 20E and 20F illustrate a method for obtaining spectral characteristic information for each pixel in three dimensions, including the depth direction (z-axis direction). As shown in Figure 20E, by arranging two sets of the measurement optical system described in Figure 5A and utilizing the convergence angle between the two 2D images detected between them, it becomes possible to collect data cubes that depend on the depth direction distance "Z0". Here, controlling (changing) the distance between the two slits 350-1 and 350-2, or controlling (changing) the distance between the two imaging lenses 310-1 and 310-2, changes the convergence angle. As a result, the measured front-to-back (depth or length) position "Z0" changes.

[0236] Figure 20F shows a method for improving the resolution in the front-to-back (depth or length) direction by controlling (changing) the distance between the imaging lenses 310-1 and 310-2 and the slits 350-1 and 350-2. Furthermore, narrowing the slit width (the width of the area through which the detection light passes) within slits 350-1 and 350-2 further improves the resolution in the front-to-back (depth or length) direction.

[0237] In other words, Figure 20E shows the case where data cubes can be collected from the optimal measurement position within the object 24 being measured. In comparison, the detection light from Figures 20F(a) and 20F(b) extends beyond the slit width within slits 350-1 and 350-2. Since it is blocked by slits 350-1 and 350-2, the detection light from Figures 20F(a) and 20F(b) does not reach the image sensors 300-1 and -2. As a result, the resolution in the front-to-back (depth or length) direction is improved.

[0238] Chapter 7: Examples of the Detection Unit Figure 5A primarily explains the operating principle of the optical property conversion element 210. Now, using Figures 21A and 21B, we will explain a method for accurate and high-speed imaging spectroscopic measurements.

[0239] Figure 21A shows a cross-sectional view (XZ cross-section) of the slit 350 (optical characteristic conversion element 210) in the plane direction including the X axis. The predetermined light 230 traveling along the "XZ plane" on the slit 350 (optical characteristic conversion element 210) moves in the "Xd" direction on the image sensor 300. Figure 21B shows a cross-sectional view (YZ cross-section) of the slit 350 (optical characteristic conversion element 210) in the plane direction including the Y axis. Different points "σ" and "ξ" on the slit 350 along the Y axis are imaged onto different points "ν" and "μ" along the Yd direction on the image sensor 300.

[0240] The image formed on the slit 350 (optical property conversion element 210) in Figures 21A and 21B is an image of the area to be measured using imaging spectroscopic measurement within the object 22 shown in Figure 20A (for example, the vicinity of the vascular region 500 in the palm 23). Then, only the image region corresponding to the simultaneously measurable range 510 within the object 22 (Figures 20C and 20D) passes through the light transmission regions "α" and "β" within the slit.

[0241] The predetermined light 230 that passes through the α region in Figure 21A is converted into a parallel beam "α0" by the collimating lens 318, and then spectrally separated on the surface of the spectroscopic element (blazed grating) 320. For simplicity of explanation, consider the case where, among the light reflected from the surface of the spectroscopic element (blazed grating) 320, the long-wavelength light remains parallel and travels in the "α2" direction, while the short-wavelength light remains parallel and travels in the "α1" direction. This parallel light then passes through the focusing lens 314 and is focused on the surface of the image sensor 300. At this time, the short-wavelength light that traveled in the "α1" direction is focused on the "γ point" within the spectral characteristic detection region 302 of the light that passed through the α region. On the other hand, the long-wavelength light that traveled in the "α2" direction is focused on the "δ point" within the spectral characteristic detection region 302 of the light that passed through the α region. In this way, each spectrally separated wavelength is focused at different positions in the "Xd" direction within the spectral characteristic detection region 302 of the light that passed through the α region. Therefore, by measuring the detection intensity distribution along the "Xd" direction within the detection region 302 for spectral characteristics of light passing through the α region, the spectral characteristics of a predetermined light 230 that has passed through the α region can be measured.

[0242] Next, the predetermined light 230 that has passed through the β region in Figure 21A is converted into a parallel beam "β0" by the collimating lens 318, and then spectrally separated on the surface of the spectroscopic element (blazed grating) 320. Of the light reflected from the surface of the spectroscopic element (blazed grating) 320, the long-wavelength light continues to travel in the "β2" direction as parallel light, and the short-wavelength light continues to travel in the "β1" direction as parallel light. This parallel light then passes through the focusing lens 314 and is focused on the surface of the image sensor 300. At this time, the short-wavelength light that traveled in the "β1" direction is focused on the "ε point" in the spectral characteristic detection region 304 of the light that has passed through the β region. On the other hand, the long-wavelength light that traveled in the "β2" direction is focused on the "ζ point" in the spectral characteristic detection region 304 of the light that has passed through the β region. In this way, each spectrally separated wavelength is focused at different positions in the "Xd" direction within the spectral characteristic detection region 304 of the light that has passed through the β region. Therefore, by measuring the detection intensity distribution along the "Xd" direction within the β-region passing light detection region 304, the spectral characteristics of a predetermined light 230 that has passed through the β region can be measured.

[0243] As explained in Figure 20D, a method for simultaneously moving multiple simultaneously measurable ranges 510-1 and -2 520 is to operate the movement mechanism 444 of the imaging lens 310 or the movement mechanism 444 of the slit 350 (optical characteristic conversion element 210) shown in Figure 21A to move the imaging lens 310 or the slit 350 (optical characteristic conversion element 210). When only the imaging lens 310 is moved, the position of the slit 350 (optical characteristic conversion element 210) is fixed. Therefore, the positions of the spectral characteristic detection region 302 of the α-region passing light and the spectral characteristic detection region 304 of the β-region passing light within the image sensor 300 are fixed. Since signal processing can be simplified, it is desirable to fix the position of the slit 350 (optical characteristic conversion element 210) and move only the imaging lens 310 when used in application fields where slow data cube acquisition is acceptable.

[0244] The weight (mass) of the imaging lens 310 is overwhelmingly larger than the weight (mass) of the slit 350 (optical characteristic conversion element 210). Therefore, in application fields where it is desired to move the simultaneously measurable ranges 510-1 and -2 at high speed 520, it is desirable to fix the position of the imaging lens 310 and move only the slit 350 (optical characteristic conversion element 210). In this case, as the slit 350 (optical characteristic conversion element 210) moves, the positions of the spectral characteristic detection region 302 for light passing through the α region and the spectral characteristic detection region 304 for light passing through the β region within the image sensor 300 shift. Therefore, for high-speed operation, it is necessary to monitor the movement position of the slit 350 (optical characteristic conversion element 210) by some means and correct the corresponding detection wavelength value for each pixel on the image sensor 300. In this way, spectral characteristic information for each light transmission region "α" and "β" of the slit 350 (optical characteristic conversion element 210) can be obtained in the "Xd direction" on the image sensor 300.

[0245] In the "YZ cross-section" direction shown in Figure 21B, the spectroscopic element 320 acts as a simple planar mirror. Therefore, the image formed on the slit 350 (optical property conversion element 210) appears directly on the image sensor 300 in the "Yd direction". That is, the predetermined light 230 emitted from the "σ point" on the slit 350 (optical property conversion element 210) is focused at the "μ point" on the image sensor 300. Similarly, the predetermined light 230 emitted from the "ξ point" on the slit 350 (optical property conversion element 210) is focused at the "ν point" on the image sensor 300. Thus, in imaging spectroscopy in this embodiment, the image formed appears in the "Yd direction" on the image sensor 300, and the spectral characteristics appear in the "Xd direction" on the image sensor 300.

[0246] Chapter 8: Service Delivery System (Platform Hierarchical Structure) In the service provision system 14 shown in Figure 1, the data cube extracted by the measurement unit 8 is passed through the system control unit 50 to the application field (various optical application fields) adaptation unit 60. Figure 22A shows the hierarchical structure of the platform controlled within the application field (various optical application fields) adaptation unit 60. Each block in Figure 22A may be composed of hardware. Alternatively, a software module may be formed for each block. If a software module is formed, it may receive command control from a higher layer via an API (application interface).

[0247] Within the top-level service integration layer 600, an integrated management control block 602 is located, which performs overall control, including the provision of services to users. Below that, within the execution control layer 610 for various processes, there are data cube collection control blocks 612 and collected data management blocks 614, billing / maintenance control blocks 616 and various service provision blocks 618.

[0248] The data cube's data acquisition control block 612 is structured to allow individual control of the depth direction measurement control unit 622, the measurement unit control block 620, the data recording unit 626, the time-varying data cube recording unit 628, and the data processing block 630. Furthermore, the measurement unit control block 620 is structured to allow individual integrated control of the temperature (far-infrared light) measurement control unit (thermography) 660, the visible light measurement control unit 650, and the near-infrared light measurement control unit 640.

[0249] The near-infrared light measurement control unit 640 then properly operates the dark current measurement control unit 642, the reference signal measurement control unit 646, and the measurement signal measurement control unit 648 to acquire highly accurate data cubes.

[0250] Figure 22B shows the control system structure within the data processing block 630 described in Figure 22A. Specifically, the data processing block 630 includes a screen region identification / separation processing unit 670, a predetermined signal (spectrum) extraction unit 680, a time-varying component extraction processing unit 700, a summation processing unit 710 for each signal extracted within a common predetermined region, and a component-specific quantification prediction processing unit (absorbance correction) 720.

[0251] The region identification / separation processing unit 670 on the screen then operates the individual identification processing unit (using visible light images) 672, the intra-individual identification processing unit (using near-infrared light images) 676, and the intra-individual predetermined region extraction unit 678, which are located at the bottom, to extract the area for which spectral characteristics to be measured.

[0252] Once the area whose spectral characteristics are to be measured is extracted in this way, the predetermined signal (spectrum) extraction unit 680 operates the comparison signal (spectrum) generation unit 682 located below it and the comparison signal (spectrum) subtraction processing unit 684 from the measurement signal to measure highly accurate spectral characteristic information of the component to be measured. At this point, the comparison signal (spectrum) generation unit 682 operates the predetermined area temperature prediction unit 692 located below it, the comparison signal temperature correction processing unit 696, and the comparison signal database 698 to correct the measurement results.

[0253] Figure 23 illustrates a series of processing steps, from data cube extraction to data processing and service provision to the user, utilizing the platform described in Figure 22A. For ease of explanation, the processing steps are explained using an "automatic blood glucose data collection method" as an example. However, the procedure described in Figure 23 is not limited to this example and can be applied to a wide range of processing procedures.

[0254] When data collection / analysis / service provision as described in Step 1 begins, the first step is the collection of data cube signals (SZT2) by the measurement unit 8. All data cube signals collected here are temporarily stored in the collected data management block 614, and the data processing described later is performed.

[0255] As the first step in data processing, the areas to be measured are extracted from all the collected data cubes. First, in step 3 of the individual identification processing (using visible light images), the individual identification processing unit (using visible light images) 672 uses the visible light image information obtained from the visible light measurement control unit 650 to extract only the human area from all the data cubes. Next, in the intra-individual identification processing (ST4) using near-infrared light images, the intra-individual identification processing unit (using near-infrared light images) 676 performs identification processing for each region. Specifically, as shown in Figure 20C, the near-infrared spectral characteristics are used to identify regions such as the vascular region 500, the fat-rich region 504, and the muscle-rich region 502. After that, the intra-individual predetermined region extraction unit 678 performs intra-individual predetermined region extraction (ST5).

[0256] Because living organisms contain many components and have complex structures, high measurement accuracy cannot be obtained by simply analyzing the spectral characteristics of a predetermined region within the organism. Therefore, the following data processing operations are performed to obtain high measurement accuracy. For example, when measuring blood glucose levels, it is necessary to extract only the spectral characteristics of glucose components contained in the blood by removing unnecessary water components from the spectral characteristics obtained from the vascular region 500. However, even if one attempts to remove the signal component from water within the vascular region 500, the spectral characteristics of water change significantly with temperature. As a result, error signals shown in Figures 18A(b) and 18A(c) are introduced. Therefore, in this embodiment, temperature correction for the spectral characteristics of water is performed in the comparison signal temperature correction processing unit 696. Specifically, the solid predetermined region temperature prediction unit 692 controls the thermography-based temperature (far-infrared light) measurement control unit 660 to measure the vascular temperature. Next, the comparison signal temperature correction processing unit 696 uses the measured vascular temperature result to read the spectral characteristics information of water for each measurement temperature that has been pre-recorded in the comparison signal database 698 and determines the spectral characteristics of water corresponding to the measured vascular temperature. Then, the comparison signal (spectrum) generation unit 682 generates spectral characteristic information of water corresponding to the blood vessel temperature determined above. Then, in the subtraction processing unit 684 of the comparison signal (spectrum) from the measurement signal, the spectral component of water is subtracted from the spectral characteristic information obtained from the blood vessel region 500 to extract the spectral characteristics of glucose. This series of processes corresponds to the predetermined signal (spectrum) extraction step (ST6).

[0257] Because cholesterol is present inside blood vessels, it is necessary to separate the glucose component from the cholesterol component in the blood vessels. Blood flow has pulsations, and the amount of the detection signal for the glucose component in the blood vessels changes accordingly. Therefore, in the time-varying component extraction process (ST7), the time-varying pulsating component is extracted within the time-varying component extraction unit 700, and the signal is separated from the cholesterol inside the blood vessels.

[0258] To further improve measurement accuracy, in step ST8, which involves summing the extracted signals, the summing processing unit 710, which processes the extracted signals within a common predetermined region, sums the signals obtained from, for example, all vascular regions 500.

[0259] In near-infrared spectroscopy, the light absorption efficiency differs for each absorption band being measured. Therefore, simply calculating the absorbance of an absorption band does not reveal the absolute amount of, for example, glucose. For this reason, in step ST9 of the component-specific quantification and prediction processing, the component-specific quantification and prediction processing unit 720 performs absorbance correction to predict the absolute value of the content of each component.

[0260] In step ST11 of the service provision process, the service is provided to the user based on the data processing results. For example, if a risk of diabetes is detected in the blood glucose measurement results, the user and their doctor may be notified via email. The service may also be provided to the user through other appropriate methods, not limited to such notifications. Once the appropriate service provision is complete, data collection / analysis / service provision is terminated (ST12).

[0261] In step ST11 of the service provision described above, various application field adaptation units 60 within the service provision system 14 are operated individually. In particular, in the service provision in this embodiment, information transmission with an external system 16 via the information transmission path 4 may be used.

[0262] For example, the distance to the object to be measured 22 may be measured (length measurement) by irradiating the object to be measured 22 with short-duration pulsed light from a light source unit 2 located at a distance, and measuring the time it takes for the pulsed light to return to the measurement unit 8. In this case, the duration of the pulsed light is preferably in the range of 0.1 nS to 100 μS.

[0263] Furthermore, by configuring a collection of photodetectors (such as a pin photodiode array) arranged monolithically or hybridly in two dimensions within the measurement unit 8, three-dimensional image acquisition becomes possible. In this case, the signal processing unit 42 determines the time until pulse light arrives for each photodetector cell. The characteristic analysis / analysis processing unit 62 then receives the time information until pulse light arrives for each photodetector cell, transmitted from the signal processing unit 42 via the system control unit 50, and generates three-dimensional image information for the object to be measured 22.

[0264] As another example, when providing services related to telemedicine, the medical / welfare-related testing processing unit 70 operates, and the information obtained from the quantification and prediction processing unit 720 for each component can be used to assist in remote diagnosis. Specifically, the blood glucose level predicted by the method described above can be used for the diagnosis of diabetes. In addition, the pulsation waveform obtained at the same time may be used for the diagnosis of arrhythmias related to heart disease.

[0265] For example, let's describe the process when an arrhythmia is detected in the pulsation waveform while measuring a specific user's blood glucose level. The specific user's pulsation waveform is extracted in the signal processing unit 42 and transmitted to the characteristic analysis / analysis processing unit 62 via the signal / information conversion unit (including decoding / demodulation processing) 44 and the system control unit 50. The characteristic analysis / analysis processing unit 62 then analyzes the pulsation waveform and performs pattern matching with the standard waveform and the pathological waveform. As a result, it is possible to detect the arrhythmia and predict the location of a defect in the heart. The arrhythmia detection result and the cardiac defect prediction information are then transmitted to the medical / welfare-related testing processing unit 70 via the system control unit 50.

[0266] Next, the medical / welfare-related testing processing unit 70 provides information (e.g., by sending an email) to the patient's primary care physician in the external system 16 via the information transmission path 4. Furthermore, if the specific user has a prior contract with a designated insurance company (non-life insurance company), the medical / welfare-related testing processing unit 70 automatically provides information (e.g., by sending an email) to the aforementioned insurance company (non-life insurance company). As a result, a service can be provided that handles troublesome procedures such as hospitalization arrangements and processing reductions for treatment costs without burdening the user.

[0267] Furthermore, if the patient is undergoing treatment for an illness or a specific disease, the treatment adaptation control / processing unit 68 will operate, allowing a doctor to remotely monitor the progress of the treatment. In other words, by tracking the temporal changes in blood glucose levels and pulse waveforms, a doctor at a distance can understand the progression of the disease and the healing process.

[0268] The above is not the only way to use user health information for providing any other services. For example, when a user signs up for a non-life insurance policy such as automobile insurance or unemployment insurance, the insurance company may use the optical device 10 to check the health status of the insured user. The insurance company may then provide a service to set the amount of compensation based on the information obtained from the optical device 10.

[0269] Furthermore, information obtained from the optical device 10 may also be used, for example, when setting interest rates and loan conditions when a user makes a deposit with a bank or when a bank provides a loan to a user (or a company managed by the user).

[0270] As another example of service delivery, information obtained from the light-utilizing device 10 can be used in educational settings. For example, the concentration level and drowsiness of students can be predicted from pulse rate, respiratory rate, eye movements, and eyelid movements. Based on the concentration level and drowsiness information obtained from the light-utilizing device 10, the lecture content can be modified as needed. This improves educational efficiency.

[0271] Furthermore, as an example of how this service delivery model can be applied, it can also be used for monitoring anomalies in public facilities. When people are in a state of tension or excitement, their heart rate tends to increase. Terrorists immediately before committing an act are often in a state of tension or excitement internally, and their faces are often tense due to this tension. Therefore, by remotely controlling surveillance cameras to simultaneously measure the heart rates of an unspecified number of people, it becomes possible to identify individuals with abnormally high heart rates and contracted facial muscles.

[0272] In this embodiment, the optical device 10 may also serve as an entry point to cyberspace by utilizing the information transmission path 4. (That is, the optical device 10 can directly connect to cyberspace via the information transmission path 4.) Examples of services provided that correspond to this entry point to cyberspace include providing a wide range of services within cyberspace, such as personal authentication when entering cyberspace, searching for and guiding users to the most suitable location after entering cyberspace, acting on behalf of users in their active actions within cyberspace, and providing security protection.

[0273] In this embodiment, the optical device 10 (or the service provision system 14 within it) can be used to automatically input and identify vascular patterns and fundus patterns at any part of the user's body, or to perform facial recognition and body shape recognition using a visible light camera built into the measurement unit 8. Therefore, in this embodiment, the user-related information collected by the optical device 10 can be used to provide a personal authentication service when entering cyberspace. Alternatively, a personal authentication service may be provided using any other method (for example, voiceprint detection).

[0274] As an example of the physical form of the optical device 10, which serves as an entry point to cyberspace, Figure 20A shows a fixed-position installation type. However, the measurement unit is not limited to this; other physical forms such as the camera section of a personal computer or mobile device (smartphone, tablet, etc.) may also be used.

[0275] Furthermore, the physical form of the display unit 18 within the optical device 10 may be a wearable terminal that can be worn by the user. This wearable terminal can take any physical form, such as glasses, a hat, a helmet, or a bag.

[0276] For example, in glasses-type or wearable headsets that realize VR (Virtual Reality) or AR (Augmented Reality), there are areas that come into direct contact with the user's skin. At least a portion of the measurement unit 8 within the above-mentioned light utilization device may be placed in this area that comes into direct contact with the user's skin.

[0277] By measuring the content of specific components such as norepinephrine in the blood through blood analysis, it is possible to estimate the psychological state of the user wearing the device, such as "tension" or "excitement." In addition, the user's psychological state can also be estimated from the location of contraction of facial muscles on the user's face. Furthermore, as mentioned above, it is possible to extract subjects who are "tension" or "excitement" from the pulse rate of people captured by remote cameras. Moreover, in this embodiment, it is possible to monitor the activity of individual nerve cells (neurons) in the user's head. Therefore, by using the optical device 10, it becomes possible for the user to efficiently access cyberspace.

[0278] Conventional methods for users to actively interact with cyberspace required actions such as vocalization or finger movements like keying. Therefore, approaching cyberspace using conventional technology was time-consuming. In contrast, this embodiment automatically and rapidly predicts the user's psychological state and intentions within the optical device 10, enabling quick and appropriate responses to cyberspace. Consequently, this embodiment allows for high-speed provision of information 72 and interaction with cyberspace as desired by the user, without requiring cumbersome actions such as vocalization or finger movements.

[0279] Furthermore, by utilizing various non-optical sensors 52 within the optical device 10, a high level of user convenience regarding interactions with cyberspace can be provided. For example, let's consider a case where gyroscopes and accelerometers are placed as various non-optical sensors 52 to detect the movement of the user's head or part of the user's body (e.g., hands or fingers). When an image (video) is displayed on the display unit 18 using a glasses-type wearable terminal such as a VR or AR device, if the user turns their head, the display screen rotates accordingly. If the user leans forward or leans back, the display screen moves forward or backward. However, if, for example, the user attempts to move at high speed in cyberspace in a game, there will be a limit to the response speed of the gyroscope and accelerometer. In this case, by predicting the user's psychological state and intentions and responding quickly and appropriately to cyberspace, the user's convenience in cyberspace can be greatly improved.

[0280] An example of service provision to a user, involving cooperation between the information provision unit 72, the collected information storage unit 74, and the signal processing unit 42 within the service provision system 14, is shown below. For example, consider a service provision example that displays a menu screen on the VR or AR screen of a wearable device (e.g., glasses or a helmet) worn by the user. By estimating the user's "likability" (or degree of dislike) with the light utilization device 10 simultaneously with the user's gaze detection, a screen preferred by the user can be displayed instantly (in a short time).

[0281] Also, for example 1. A wearable device such as a VR or AR device is incorporated into the display unit 18. 2. The gyroscope and accelerometer within the various non-optical sensors 52 detect the movement of the user's head and fingers (or hands), 3. Using the user's biological signals measured by the measurement unit 8, the signal processing unit 42 outputs information about the user's biological system. 4. When the system control unit 50 integrates and uses the above information, An identity in cyberspace is formed for users utilizing the optical device 10. Any services can then be provided to this cyberspace identity. Furthermore, it becomes possible to provide even more services to users by operating robots placed in the real world via cyberspace.

[0282] For example, a self-walking robot installed in a remote location can be operated to provide tourism services to users. Similarly, a self-walking robot installed in a hospital or facility can be operated to provide remote care services. Conventional technology required voice input or the user's finger (or hand) movements for identity manipulation in cyberspace and robot operation in the physical world. Using the optical device in this embodiment eliminates the need for cumbersome voice commands or finger movements, enabling high-speed operation. This significantly improves the convenience of service provision in this embodiment.

[0283] Another embodiment of service provision utilizing cyberspace may be used for marketing applications. For example, while displaying predetermined images or videos on a VR or AR screen via the information provision unit 72, the user's emotions and intentions may be estimated in real time within the light utilization device 10. Images, videos, and audio displayed when the user shows favorability or interest are appropriately saved in the collected information storage unit 74. The external system 16 collects the information (images, videos, and audio) stored in the collected information storage unit 74 via the information transmission path 4 at an appropriate time. Next, the information collected within the external system 16 is analyzed to extract products with purchasing power, and this information may be provided to the sales companies of the corresponding products for a fee.

[0284] In the provision of services in cyberspace in this embodiment, personal information management is extremely important. Therefore, the personal information management service itself is a very important service in the provision of services in this embodiment. When a specific user enters cyberspace and engages in activities within cyberspace, an account ID (identification) is used to identify each individual user. When the user's health information and preference information obtained from the optical device 10 is linked to the above account ID, it leads to personal information.

[0285] As an example of service provision in this embodiment, a personal information management agent may be permanently stationed in the collected information storage unit 74 or in the characteristic analysis / analysis processing unit 62. Information such as "which facial muscles of the user are contracting," "the content ratio of each component in the blood," or "which nerve cells are active (firing (nerve impulse))" is analyzed in the signal processing unit 42. Advanced judgments such as "estimating user emotions," "estimating user preferences," and "estimating user will" using this information are performed in the characteristic analysis / analysis processing unit 62. The information obtained by the characteristic analysis / analysis processing unit 62 is stored in the collected information storage unit 74 as appropriate. Then, in response to a request from the external system 16, the necessary information is transmitted to the external system 16 via the information transmission path 4.

[0286] In this service provision example, the personal information management agent links the information obtained by the characteristic analysis / analysis processing unit 62 to externally transmittable range information. Therefore, externally transmittable range information is set for all information stored in the collected information storage unit 74. Then, for each information transmission request from the external system 16, the personal information management agent determines whether or not transmission to the outside is permitted. By performing the personal information management service within the optical utilization device 10 in this way, highly reliable protection of personal information becomes possible.

[0287] Another example of service provision application in this embodiment is its use as a tool for creating artificial intelligence (training artificial intelligence). For example, the artificial intelligence used here could be a "multi-input and multi-output parallel processing method with learning capabilities" used in deep learning or quantum computing technologies.

[0288] Examples of complex analysis / processing suitable for multi-input, multi-output parallel processing include image analysis and understanding, language processing and understanding, and advanced decision-making adapted to complex situations. These tasks are given simultaneously to both the human and the artificial intelligence (AI) (object 22). The human's answer can then be considered the correct answer, and the AI ​​can be trained to approach that correct answer through learning feedback.

[0289] These tools may also be executed in cyberspace. In this case, the artificial intelligence to be learned is pre-installed on an external system 16, and the correct answer given by a human can be notified to the artificial intelligence via the information transmission path 4 from the optical device 10 (or application field adaptation unit 60).

[0290] As an example of service provision, the above is not limited to any other example, but any service provision may be performed in which the optical device 10 is connected to a cyberspace built on an external system 16 via the information transmission path 4.

[0291] Chapter 9 Applied Equipment Figure 24 shows an example of an application of this embodiment. For example, a light propagation path 6 from the light source unit 2 to the measurement unit 8 may be installed along the path from which the substance separated by liquid chromatography is taken to the mass spectrometry unit, and the component analysis of the substance separated by liquid chromatography may be performed.

[0292] Figure 25 illustrates a method for simultaneously analyzing each component separated two-dimensionally by two-dimensional electrophoresis using imaging spectroscopy. An anode 912 and a cathode 918 are positioned within the two-dimensional electrophoresis analyzer 900. Within the two-dimensional electrophoresis analyzer 900, the SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) direction 930 is defined along the gel concentration gradient direction 922 of the gradient gel 920. An isoelectric focusing direction 940 is set perpendicular to this direction.

[0293] A light source unit 2 is installed at the rear of the two-dimensional electrophoresis analysis vessel 900. A predetermined light 230 emitted from this light source unit 2 passes through the inside of the two-dimensional electrophoresis analysis vessel 900 and reaches the measurement unit 8 located at the front. The inside of this measurement unit 8 has the optical structure already described using Figures 5A, 21A, and 21B.

[0294] A voice coil, for example, is built into the moving mechanism 444 connected to the slit 350 via the connecting part 950, and current is passed through this voice coil to move the slit 350. As already explained using Figures 20E and 20F, the distance between the imaging lens 310 and the slit 350 needs to be maintained with high precision. Therefore, if the imaging lens 310 is fixed, for example, a mechanism is needed to prevent the distance between the imaging lens 310 and the slit 350 from changing when the slit 350 moves. For this reason, a sliding slit sliding / sensor part 960 is installed on a part of the slit 350.

[0295] Inside the slit sliding / sensor section 960, there is a rotating column 966 that rotates and slides relative to a portion of the slit 350, and a rotating column support section 964 that fixes it in place. A spring 968 that presses down on the rotating column support section presses the rotating column support section 964 toward the slit 350. By providing this mechanism that rotates and slides relative to a portion of the slit 350, the distance to the imaging lens 310 is kept constant even when the slit 350 moves, and the high-speed movement of the slit 350 is facilitated.

[0296] Furthermore, a slit position detection light source 972 and an optical slit position detector 978 are arranged inside the slit sliding / sensor section 960, enabling accurate detection of the slit position by optical means. The detection signal here is used for slit position feedback 962, and the corresponding measurement wavelength value for each pixel in the "Xd" direction within the image sensor 300 is converted.

[0297] Chapter 10: High-Precision Measurement Methods in Optical Applications Figure 26A shows a high-precision measurement method in this embodiment for optical applications. Figure 26A is an excerpt of the main parts of the optical utilization device 10 described in Figure 1. Specifically, optical measurement 1002 is performed on the object to be measured 24 in the measurement unit 8. The results of the optical measurement 1002 obtained therein are then analyzed in the signal processing unit 42 to extract necessary information 1004.

[0298] In order to perform highly accurate information extraction 1004, it is necessary to minimize disturbance noise in both the optical measurement 1002 and information extraction 1004 processes. When measuring in the optical application field 100 using the optical utilization device 10, two types of disturbance noise, optical noise and electrical noise, are easily introduced. Therefore, in order to perform high-precision measurements, it is desirable to reduce disturbance noise in two ways: optical disturbance noise reduction and electrical disturbance noise reduction 1012.

[0299] In particular, in this embodiment, highly accurate information extraction 1004 is performed using an optical system capable of reducing optical noise. Conventional methods for reducing optical disturbance noise in optical utilization devices 10 used in optical application fields 100 have only considered stray light contamination αc1. However, in reality, large optical disturbance noise is generated from optical interference αc2 that occurs along the optical propagation path 6. Therefore, conventional techniques have had the problem of not being able to fully demonstrate the effect of electrical disturbance noise reduction processing. Furthermore, when large optical disturbance noise caused by optical interference αc2 occurs, the good performance of all optical application fields 100 shown in Figure 2 is hindered.

[0300] Therefore, the optical utilization device 10 in this embodiment uses an optical system that reduces optical disturbance noise originating from optical interference αc2. After reducing the influence of optical interference αc2 occurring along the optical propagation path 6, a process to reduce optical disturbance noise caused by other factors or a process to reduce electrical disturbance noise 1012 may be performed. Alternatively, the optical utilization device 10 in this embodiment may have an optical system that reduces optical disturbance noise originating from optical interference αc2, and may also perform a combination of reducing optical disturbance noise caused by other factors and reducing electrical disturbance noise 1012.

[0301] In this embodiment, the optical system for reducing optical disturbance noise originating from optical interference αc2 adds the intensity of light 202 and 204 that have passed through regions 212 and 214 with different optical path lengths. As a result, the different noise patterns (noise characteristics) that occur individually within each of the individual light 202 and 204 are averaged (smoothed), and as a result, the optical disturbance noise originating from optical interference αc2 is reduced. This optical system for reducing optical disturbance noise originating from optical interference αc2 may be placed at any position within the light utilization device 10. That is, it may be placed in the optical system before irradiating the object to be measured 22 with light (for example, within the light source unit 2). Alternatively, it may be placed in the optical system through which the detection light obtained from the object to be measured 22 passes (for example, within the measurement unit 8).

[0302] In this way, the influence of optical interference αc2 occurring along the optical propagation path 6 is reduced, and by performing a reduction process for optical disturbance noise or electrical disturbance noise 1012 caused by other factors, the reduction of optical disturbance noise or electrical disturbance noise 1012 can be effectively achieved.

[0303] Furthermore, in the embodiment shown in Figure 26A, optical disturbance noise reduction or electrical disturbance noise reduction 1012 is performed by utilizing the information obtained from the detected light. Specifically, first, the predetermined light is irradiated onto the object to be measured, and first information is obtained from the predetermined light or the detected light obtained from the object to be measured. Next, optical disturbance noise reduction or electrical disturbance noise reduction 1012 is performed on the signal obtained from the detected light using the first information. Then, second information is obtained from the signal after optical disturbance noise reduction or electrical disturbance noise reduction 1012 has been performed.

[0304] In other words, predetermined light emitted from the light source unit 2 is irradiated onto the object to be measured 22. The wavelength of this predetermined light may be visible light between 400 nm and 700 nm. However, it is not limited to visible light, and near-infrared light between 700 nm and 2.5 μm, infrared light between 2.5 μm and 20 μm, or far-infrared light with a longer wavelength may also be used. In this case, the light-emitting part 470 in the light source unit 2 may be various lamps such as halogen lamps, mercury lamps, xenon lamps, or incandescent light-emitting elements. However, it is not limited to these, and an LD (Laser Diode) or LED (Light Emitting Diode) may also be used as the light-emitting part 470.

[0305] The measurement unit 8 then detects the detection light obtained from the object to be measured 22. Here, the transmitted light from the object to be measured 22 may be used as the detection light, or the reflected light from the object to be measured 22 may be used as the detection light. In addition, scattered light from the object to be measured 22 may also be used as the detection light.

[0306] When the same wavelength light as the predetermined light is used as the detection light, it becomes possible to measure the light absorption characteristics (absorbance described later) for each wavelength within the object 22. On the other hand, when a wavelength longer than the predetermined light is used as the detection light, it becomes possible to measure Raman scattering characteristics and fluorescence and phosphorescence characteristics within the object 22.

[0307] Next, the signal from the detected light obtained by the measurement unit 8 is processed in the signal processing unit 42 to obtain the first information. Then, using this first information, a noise reduction operation is performed in the signal processing unit 42. As a result, a highly accurate (highly reliable) second information extraction 1000 is performed.

[0308] The first information used here for reducing disturbance noise relates to at least one of optical disturbance noise reduction 1012 or electrical disturbance noise reduction 1012. However, it is not limited to this, and this first information may relate to both optical disturbance noise reduction and electrical disturbance noise reduction 1012.

[0309] The first or second piece of information 1004 extracted within the signal processing unit 42 is transferred 1006 via the information transmission path 4. The transferred information 1004 is then stored 1010 in the collected information storage unit 74. Alternatively, it may be displayed 1008 to the user via the display unit 18 or the information provision unit 72. Furthermore, it may also be transmitted to an external system 16 via the information transmission path 4.

[0310] As the transfer format 1014 used during this information transfer 1006, existing color image signal or color video signal formats such as RGB (Red, Green, and Blue) may be used. However, it is not limited to these; for example, multiplexing technology defined in the MPEG (Moving Picture Experts Group) standard may also be used. Specifically, images and videos are distributed and time-divided within a video pack. The information 1004 extracted in the signal processing unit 42 is then stored in a proprietary information pack and inserted between the video pack rows. This information pack may be uniquely defined for this embodiment, or it may be a Sub-picture Pack (SP pack) defined in the DVD (Digital Versatile Disk) standard. Furthermore, it may be written in a hypertext format similar to an HTML (Hyper Text Markup Language) document (for example, XML (Extended Markup Language) format).

[0311] Here, the smallest unit of output content obtained from the measurement unit 8 or the signal receiving unit 40 is called "data." The collection of such data or the relationships between data are called "signals." The results of data processing and data analysis of that data, or the results of processing the signals or signal analysis, are called "information." This data processing / analysis and signal processing / analysis are performed within the signal processing unit 42. In other words, the measurement unit 8 or the signal receiving unit 40 outputs data or signals to the signal processing unit 42. The signal processing unit 42 then uses that data or signals to generate information and outputs this information to the system control unit 50.

[0312] The information generated by the signal processing unit 42 is basically limited to information that can be extracted or estimated solely from the data and signals obtained from measurements. The characteristic analysis / interpretation processing unit 62 then performs more advanced estimation and inference of information. In other words, the characteristic analysis / interpretation processing unit 62 integrates the information output by the signal processing unit 42, the information previously stored in the collected information storage unit 74, and the information collected from the external system 16 to perform more advanced estimation and inference of information.

[0313] For example, in the spectral characteristics measured by the measurement unit 8, the light intensity values ​​measured for each measurement wavelength correspond to the data. Also, when the measurement unit 8 measures images such as still images or moving images, the intensity values ​​and chrominance values ​​for each pixel correspond to the data. Furthermore, for data cubes that have spectral characteristic signals for each pixel, the light intensity values ​​for each wavelength within a specific pixel correspond to the data.

[0314] Furthermore, examples of advanced information that the characteristic analysis / processing unit 62 estimates and infers include the user's preferences and the user's emotions and intentions that change over time. In addition, when providing a predetermined service to the user, the characteristic analysis / processing unit 62 forms an identity in cyberspace. This characteristic analysis / processing unit 62 may then act as an agent and operate the identity in cyberspace or a robot in the real world.

[0315] Figure 26B shows a list summarizing examples of information used in this embodiment. All of these examples of information are extracted / generated within the signal processing unit 42 using various signals (or various data) obtained from the measurement unit 8 and the signal receiving unit 40. As explained above, the information extracted first 1004 and used for reducing disturbance noise corresponds to "first information," and the information extracted after reducing disturbance noise using the first information corresponds to "second information." The examples of "information" shown in Figure 26B are a list that combines the first and second information. Therefore, all the information listed in Figure 26B may correspond to either "first information" or "second information." Also, the same information may be used simultaneously for both "first information" and "second information."

[0316] When the information related to this embodiment is classified into category 1020, examples include the influence of optical effects that occur unnecessarily during measurement, information related to the shape and position of the object to be measured 22, detection information of the moving object itself when the position of a specific part within the object to be measured 22 moves, the composition ratio of the constituent parts within the object to be measured 22, and activities within the object to be measured 22 that change over time.

[0317] Unnecessary optical effects occur during measurement, whether it is during the measurement of spectral characteristics or the measurement of image data (image signals). Among these, a specific example 1024 of optical effects occurring inside the object being measured 22 is the absorption of light αa1 of other components. Other specific examples 1024 include light scattering characteristics αa2 and optical interference / reflection characteristics α3.

[0318] In addition to the above, other unwanted optical effects include optical effects on the surface of the object being measured 22. Specifically, 1024, the inclination of the surface causes the detected light to refract αb1, resulting in a shift in the image formation position within the detection optical system. Furthermore, if the surface of the object being measured 22 has a fine uneven surface, diffraction and interference αb2 from these surfaces will occur.

[0319] Furthermore, optical effects occurring along the optical propagation path 6 also have a significant impact, particularly those occurring unnecessarily. In particular, stray light αc1 introduced along the optical propagation path 6 greatly reduces the accuracy of optical measurements. The state of optical interference αc2 occurring along the optical propagation path 6 may also be collected as first extracted information 1004. The signal processing unit 42 can process the raw signal obtained from the measurement unit 8 or the signal receiving unit 40 and remove the component of the first extracted information 1004 from it. This allows for the extraction of second information 1004 with high measurement accuracy (and measurement reliability).

[0320] Extracted information 1004 related to the shape and position of the object to be measured 22, or the detection of moving objects found within it, is often obtained mainly through data analysis (signal analysis) of image data (or data cubes). In other words, specific examples 1024 of shape contour information and feature information corresponding to the extracted information summary 1022 included in category 1020 related to the shape and position of the object to be measured 22 include information that has been region-divided β2 for each component within the image signal. This is obtained as a result of performing shape contour extraction within the image data (image signal) in the signal processing unit 42.

[0321] Next, when a pattern matching operation is performed on the contour shape, marginal region information β1 is extracted from the region division information β2 for each component in the image signal. For example, the marginal region β1 in the data cube does not contain spectral characteristic information. Therefore, by using this marginal region information β1 as the first extracted information and performing signal analysis (data analysis) of spectral characteristics obtained from regions other than the marginal region, spectral information from only the necessary parts is generated as the second extracted information 1004, which has the advantage of improving the efficiency of spectral characteristic analysis for the data cube. Furthermore, if spectral characteristic analysis is performed only on pixels corresponding to important parts in the data cube, the efficiency of spectral characteristic analysis can be further improved. In this way, if the positional information β3 of feature parts in the image signal can be used as the first extracted information 1004, the efficiency of generating the second extracted information 1004 can be improved.

[0322] Alternatively, the contour information of the boundary region where the feature region exists may be used as the position information β3 of the feature region within the image signal. Instead, outputting the centroid position information β4 of the feature region in the form of the corresponding pixel position information within the image sensor 300 allows for a reduction in the amount of information required for the position information β3 of the feature region.

[0323] When moving objects such as cars, ships, or airplanes are captured in a background image, there is a method to use only the information of those moving objects as the first extracted information 1004. In this case, the extracted information summary 1022 indicates that the region of the moving object within the image corresponds to the extracted information 1004. Specific examples 1024 of this region of the moving object include information γ1 regarding the range of the moving object region, γ2 regarding the movement speed of the moving center of gravity within the image sensor 300, and γ3 regarding the time-series shape change information of the moving object itself, which can also be used as extracted information.

[0324] The extracted information 1004, mainly obtained by analyzing the spectral characteristic signals, includes content that can be categorized 1020 into compositional ratios of constituent parts and activities that change over time. The spectral characteristic signals of infrared light (included in the wavelength range of 2.5 μm to 20 μm) and near-infrared light (included in the wavelength range of 0.8 μm to 2.5 μm) (including fluorescence spectroscopy such as Raman scattering and phosphorescence spectroscopy) contain information on light absorption caused by specific intramolecular vibrations or vibrations within specific functional groups (atomic groups). Therefore, by extracting the light absorption information of specific wavelengths of light contained in these spectral characteristic signals or its changes over time, information on the compositional ratios of constituent substances and biological activity within the object being measured 22 can be extracted 1004.

[0325] The presence or absence of light absorption due to carbon compounds contained within the organic material allows for the determination δa1 of whether the object being measured 22 is composed of organic or inorganic material. For example, if methyl or methylene groups are present, light absorption occurs in the range of 1.15 μm to 1.25 μm or 1.65 μm to 1.8 μm. Conversely, in inorganic materials, light absorption within the above wavelength range often does not occur.

[0326] Furthermore, the compositional analysis results of the measured object 22 allow for determination δa2 of whether it is an animal, plant, or artificial substance. Animals contain proteins, while plants contain carbohydrates. On the other hand, artificial substances contain the methyl and methylene groups mentioned above, but the detection of proteins and carbohydrates is rare. Thus, it is possible to distinguish between carbohydrates / lipids / proteins from the wavelength range in which a lot of light absorption occurs δa4.

[0327] Pure water exhibits significant light absorption, particularly in the 1.4 μm to 1.5 μm range and in the wavelength range above 1.8 μm. Therefore, the water content δa3 can be estimated from the magnitude of light absorption in these wavelength ranges.

[0328] Protein structures, basic amino acids, and saturated and unsaturated fatty acids absorb light in the wavelength range described later using Figure 31B. Therefore, the degree of light absorption at different wavelengths allows us to estimate the distinction between protein structures and basic amino acids (δa5) and the degree of unsaturation (δa6) of fatty acids.

[0329] Even when extracting information on the composition ratio of the same constituent parts, the method of information extraction 1004 differs significantly depending on whether the object to be measured 22 is a liquid or a solid that does not contain water. When a small amount of a specific substance is contained in the liquid, most of the spectral characteristic signal obtained from the measurement unit 8 or the signal receiving unit 40 contains spectral characteristic information of the solvent. Therefore, in this case, it is necessary to remove the spectral characteristic information component of the solvent alone as the first extracted information 1004 from the spectral characteristic signal obtained from the measurement unit 8 or the signal receiving unit 40, and then extract the second spectral characteristic information 1004 obtained from the characteristic substance. Specific examples 1024 of extracted information 1004 related to the content of substances in the liquid include blood glucose levels, the content of sugar components in urine δb1, and the content of specific substances in the blood δb2.

[0330] The information extraction category 1020 of the information extracted 1004 by the signal processing unit 42 includes information related to biological activity, as well as information related to biological activity. Specific examples 1024 include the pulse rate and respiratory rate ε1 of the user using the optical device 10, muscle contraction ε2, nervous system signal pulses generated during nerve impulse firing and ion pump activity ε3 immediately following, and chemical signal transmission ε4 occurring within or between cells.

[0331] In Figure 26B, individual symbols 290 are assigned to each of the 1024 specific examples of information to be extracted. To clarify the relationship between the detailed embodiments described later and Figures 26B and 26A, the individual symbols 290 assigned here will also be referenced in the following explanation.

[0332] To improve the accuracy and reliability of the information extraction 1004 described above, optical disturbance noise reduction and electrical disturbance noise reduction 1012 are necessary. In particular, in this embodiment, an optical noise reduction method and an electrical disturbance noise reduction method are combined to enable high-precision (high-reliability) measurement. Before explaining the specific optical disturbance noise reduction and electrical disturbance noise reduction 1012, the causes of these disturbance noises 1036 will be explained.

[0333] Figure 26C shows a table listing the causes of disturbance noise generation 1036 and countermeasures 1038 for each measurement target area 1032 within the object 22 being measured. Regardless of the measurement target area 1032, the causes of electrical disturbance noise generation 1036 are similar and include shot noise, thermal noise, electromagnetic induction noise, etc.

[0334] As a method 1038 for reducing electrical disturbance noise in this embodiment, the detection signal may be bandwidth-limited to extract only the carrier component E1. However, in this embodiment, a lock-in amplifier E2 may also be performed. This lock-in amplifier E2 requires synchronization of the frequency and phase of the reference signal with respect to the detection signal. Therefore, in this embodiment, various information included in the time-varying activity category 1020 in Figure 26B may be used in the first extracted information 1004 to perform the above-mentioned frequency and phase synchronization.

[0335] In addition to the electrical disturbance noise reduction method 1038, an error correction function E3 for digitized signals may also be used. Specifically, techniques such as PRML (Partial Response Most Likelihood) may be used to automatically correct the signal sequence to what is considered the most appropriate.

[0336] The causes of optical disturbance noise 1036 differ slightly depending on the measurement area 1032 within the object 22 being measured. A common cause of optical disturbance noise 1036 in both cases is the influence of optical interference noise. In this embodiment, as a measure to reduce this optical interference noise, at least one of the following is performed: averaging (smoothing) of interference noise components L1 (averaging interference noise elements) and reducing the degree of coherence L2 (reducing a degree of coherence).

[0337] Optical interference noise includes two different types of interference noise. Both types of interference noise are related to the coherence length ΔL0, which corresponds to the length of the wave train. (That is, adjacent wave trains are incoherent with each other.) Furthermore, when the intensities of light 202, 204, and 206, which are incoherent with each other, are added together, the interference noise components that are uniquely generated within each of the light 202, 204, and 206 are averaged (smoothed) L1, and the amount of interference noise is reduced in all types of interference noise.

[0338] One of the two distinct types of interference noise described above is due to the temporal coherence of light and primarily manifests in the spectral characteristics. The reduction effect of this interference noise (a spectral degree of temporal coherence) is related to the phase distribution characteristics within individual light beams 202, 204, and 206, as already explained using Figures 8 to 11.

[0339] The other issue stems from the spatial coherence of light and primarily manifests as spatial intensity unevenness. This spatial intensity unevenness is often referred to as speckle noise. The reduction effect of this interference noise caused by spatial coherence (speckle noise amount or speckle constant Cs value) is related to the change in the irradiation angle of the individual light beams 202, 204, and 206 when illuminating the object 22 being measured. (Details will be explained in Chapter 12.) However, even when the phase distribution characteristics of the individual light beams 202, 204, and 206 were changed, the reduction effect of interference noise caused by spatial coherence was confirmed.

[0340] Other causes of optical disturbance noise 1036 include the intrusion of other optical effects. As a countermeasure against the intrusion of these other optical effects, in this embodiment, the signal processing unit 42 performs calculation processing (signal processing or signal analysis) L3 between the measurement signals to remove the influence of the intruded other optical effects. That is, when a measurement signal is acquired from the measurement unit 8 or the signal receiving unit 40, the signal processing unit 42 extracts information based on the results of other optical effects from the measurement signal 1004 and generates first extracted information 1004. Then, the component of the first extracted information 1004 is removed from the measurement signal. As a result, a second information extraction 1000 is performed after the influence of other optical effects has been removed.

[0341] One of the causes 1036 of optical disturbance noise that occurs depending on the measurement area 1032 within the object 22 is that it does not occur when measuring the overall characteristics of the object 22 as a whole, but only occurs when measuring the local characteristics within the object 22. One of the causes 1030 of this optical disturbance noise is the influence of ambient light that enters from outside the local area being measured.

[0342] As a method 1038 to reduce the influence of ambient light entering from outside the local area to be measured, in this embodiment, aperture restrictions may be set at the imaging position or confocal position relative to the local area to be measured to block unwanted ambient light L4. This prevents, for example, when performing three-dimensional measurement inside the object 22 to be measured, from mismeasuring detected light from depth positions other than the local area to be measured as ambient light.

[0343] In Figure 26C, individual symbols 290 are set for each of the disturbance noise reduction methods 1038. To clarify the relationship between the detailed embodiments described later and Figures 26C and 26A, the individual symbols 290 set here will also be referenced in the following explanations.

[0344] Chapter 11: The mechanism by which wave chains are continuously and repeatedly generated along the direction of light propagation. Figure 27A shows the characteristics near the end region of a single wave thread obtained from experimental measurements. The vertical axis of Figure 27A represents the light transmittance when panchromatic light (light with multiple different wavelengths within a wide wavelength range) emitted from a halogen lamp passes through a glass plate with a thickness of 138.40 μm. Here, the horizontal axis of Figure 27A represents the measurement wavelength λ0 of the panchromatic light, and the light transmittance characteristics for each wavelength λ0 from 1.3 μm to 1.6 μm can be seen from Figure 27A.

[0345] When light of each wavelength passes through a glass plate, optical interference occurs between the zero-order transmitted light traveling in a straight line through the glass plate and the primary reflected light that has been reflected twice from the entrance and exit surfaces within the glass plate. Therefore, the amount of change in the amplitude of the optical transmittance oscillation between the measured wavelengths in Figure 27A represents both the interference visibility and the magnitude of the wave chain amplitude. Thus, the area around a measured wavelength λ0 of 1.32 μm corresponds to the end region of one wave chain.

[0346] The theoretical calculation results shown in Figure 27A represent the results obtained using Equation 11. Since the wavelength resolution Δλ of the spectrometer used in this experiment is approximately 7.5 nm, the coherence distance ΔL0 corresponding to the length along the direction of optical propagation of a single wave chain can be calculated from Equation 1.

[0347] Figure 27B shows a conventionally known model of wave facies formation. The horizontal axis of Figure 27B represents the spatial distance along the direction of optical propagation. The vertical axis of Figure 27B represents the electric field amplitude at a given time.

[0348] When the center wavelength of one wave chain is defined as λ0, Figure 27B(c) shows the electric field amplitude distribution of light with a center wavelength of λ0 at a predetermined time. Figure 27B(a) shows the electric field amplitude distribution of light with a wavelength of λ0-Δλ / 2. Similarly, Figures 27B(b), 27B(d), and 27B(e) show the electric field amplitude distributions of light with wavelengths of λ0-Δλ / 4, λ0+Δλ / 4, and λ0+Δλ / 2, respectively. Similarly, Figure 27B(f) represents the electric field amplitude distribution of the entire wave chain obtained by adding the amplitudes of each wavelength of light (amplitude synthesis or addition of each electric field amplitude value).

[0349] Consider the case where the phases of all wavelengths of light in Figures 27B(a) to (e) coincide at position α. ​​Here, the electric field amplitudes of all wavelengths of light reach their maximum values, so the amplitude of the wave chain, when the amplitudes are added together, is also maximum. However, because the wavelengths of each wavelength of light are different, a phase shift occurs between each wavelength of light as we move from position α to position β. Consequently, at position β, which is shifted by the coherence distance ΔL0 from position α, the electric field amplitude values ​​for each wavelength of light become random. As a result, the amplitude of the wave chain, when the amplitudes are added together at position β, becomes "0". Position β in Figure 27B corresponds to the vicinity of the end region of a single wave chain in Figure 27A where the measured wavelength λ0 is near 1.32 μm.

[0350] According to conventional wave chain formation mechanism models, there are no locations beyond position β (positions γ and δ) where the phases of each wavelength of light coincide. Therefore, conventional wave chain formation mechanism models cannot explain the principle by which wave chains are continuously and repeatedly generated along the direction of light propagation.

[0351] Furthermore, in conventional wave formation mechanism models, 1. Small amplitude wave streams appear at position γ, 2. The wave-fed phase here is inverted with respect to the wave-fed phase between positions α and β. However, a detailed examination of the measurement data shown in Figure 27A revealed that the experimental results expected in 1. and 2. above were not obtained. From these experimental results, it can be inferred that "a mechanism other than the conventionally known wave formation mechanism model is at work in which wave chains are continuously and repeatedly generated." For the first time in this specification, we propose a mechanism model for the continuous and repeated generation of wave chains.

[0352] As shown in Figures 27B(a) to (f), when a wave chain contains light with wavelengths from λ0-Δλ / 2 to λ0+Δλ / 2 (plane waves) (amplitude summing or amplitude value synthesis), the relation for this wave chain is:

[0353]

number

[0354]

number

[0355]

number

[0356]

number

[0357]

number

[0358]

number

[0359] The upper right-hand side of equation 29 represents the "preceding wave chain" near the terminal region. The lower side of equation 29 represents the vicinity of the starting region of the "following wave chain". A particularly noteworthy point is that a "reversal of the phase angle propagation direction" occurs between the upper right-hand side of equation 29 and the lower side of the equation.

[0360] In conventional wave chain formation mechanism models, beyond position β (at positions γ and δ), there is no location where the phases of the individual wavelengths of light coincide, and therefore, a "sequential wave chain" does not occur. However, when a "reversal of phase angle" occurs near the terminal region of the "leading wave chain" (near position β in Figure 27B), phase synchronization between the constituent wavelengths of light begins immediately thereafter. As a result, a "sequential wave chain" is generated.

[0361] In electromagnetism, electromagnetic waves propagate through space through the interaction of oscillating electric and magnetic fields that occur in mutually orthogonal directions. However, near the terminal region of a "leading wave chain," the phases of the oscillating electric and magnetic fields become random across wavelengths of light. This random state of the oscillating electric and magnetic fields may be creating the conditions for "reversal of the phase angle propagation direction."

[0362] Incidentally, the spatial range that satisfies the conditions of equation 28 has a certain degree of width. In other words, the starting position of the 'sequential wave' within the terminal region of the 'preceding wave' is not uniquely determined. Therefore, a random amount of phase shift occurs between the 'preceding wave' and the 'sequential wave'. As a result (because the phase is not fixed), a 'non-interfering' relationship is created between the 'preceding wave' and the 'sequential wave'. That is, if a random phase shift occurs between the preceding and succeeding waves that are continuously and repeatedly generated, integrating the preceding and succeeding waves over time will yield essentially the same result as 'intensity addition (combination of intensity values)'.

[0363] The difference between the mechanism model in which wave chains are continuously and repeatedly generated, as described above, and the conventionally known wave chain formation mechanism model will be explained from a different perspective. As shown in Figure 27B(f), in the conventionally known wave chain formation mechanism model, the phase angle change is fixed near the terminal position (position β) of the preceding wave chain. Therefore, not only is the generation of the following wave chain inhibited, but a phase inversion occurs at position γ (which contradicts experimental results). In contrast, in the mechanism model in which wave chains are continuously and repeatedly generated, the phase angle direction is reversed near the terminal position (position β) of the preceding wave chain, and a following wave chain with randomly changing phases is continuously generated.

[0364] In this embodiment, optical interference noise is reduced by utilizing the principle of wave chain generation, which occurs continuously and repeatedly along the direction of light propagation. Specifically, within the optical system included in the optical utilization device 10 or service provision system 14 used in this embodiment, a first region 212 and a second region 214 are configured, with optical path lengths differing by at least twice the coherence distance ΔL0. The initial light 200 emitted from the light-emitting unit 470 is subjected to wavefront division or amplitude division. As a result, a portion of the initial light 200 passes through the first region 212 as the first light 202. At least the remaining portion of the initial light 200 passes through the second region 214 as the second light 204. The first light 202 after passing through the first region 212 and the second light 204 after passing through the second region 214 are then intensity-added (combined in terms of optical intensity).

[0365] Since wave chains are continuously and repeatedly generated along the direction of light propagation, different wave chains are always included in the first light 202 and the second light 204 during intensity summation (optical intensity synthesis). Because the difference in optical path length between the first region 212 and the second region 214 is greater than or equal to twice the coherence distance ΔL0, the first wave chain included in the first light 202 and the second wave chain included in the second light 204 do not interfere with each other.

[0366] It is possible that a first interference noise is generated within the first wave stream contained in the first light 202, and a second interference noise is generated within the second wave stream contained in the second light 204. However, the characteristics of the first interference noise and the second interference noise are different, and they do not interfere with each other. Therefore, the summation of their intensities (optical intensity synthesis) causes averaging (smoothing) between the first and second interference noises. As a result of this averaging process, a cancellation effect occurs between the interference noises, and the overall interference noise is reduced.

[0367] Chapter 12: Methods for Reducing Spatial Interference Noise (Interference Noise Caused by Spatial Coherence) Speckle noise is known as optical interference noise generated by light with a high degree of spatial coherence, such as laser light. In this embodiment, we will explain the method for averaging L1 of this interference noise component.

[0368] Figure 28A(a) illustrates the basic principle of spatial interference noise generation. Two light reflection regions 1046 are arranged separated by a distance P. Incident light 1042 is perpendicularly incident on these light reflection regions 1046, and Figure 28A(a) shows the reflection intensity of the reflected light 1048 reflected in the θ0 direction. According to the theory of optical interference, the reflection intensity at that time is cos 2 It is proportional to (πPθ0 / λ). The important point here is that the reflection intensity of the reflected light 1048 changes periodically in the reflection direction θ0. This periodic change in reflection intensity is related to spatial interference noise.

[0369] Expanding on Figure 28A, consider the case where multiple light reflection regions 1046 are regularly arranged with a period P. If the position of the user's eye observing the reflected light 1048 is fixed, the direction of reflection θ0 entering the user's eye changes for each reflection location within the multiple light reflection regions 1046. As a result, areas appear brighter due to constructive interference between reflection amplitudes from adjacent light reflection regions 1046, and areas appear darker due to cancellation of reflection amplitudes. This type of appearance is called a speckle noise pattern.

[0370] Figure 28A(b) shows that the incident angle of the incident light 1042 to the two light reflection regions 1046 is θ i This shows the reflection intensity of the reflected light 1048 reflected in the θ0 direction when it changes as follows. According to the theory of optical interference, the reflection intensity at that time is cos 2 {πP(θ0-θ i It changes as ) / λ}.

[0371] As explained in the previous chapter, different wave chains do not interfere with each other, so photosynthesis between different wave chains is equivalent to intensity addition (combination of light intensity values). For example, as shown in Figure 28A(a), a first light 202 containing a portion of at least one wave chain is incident perpendicularly on two light reflection regions 1046. At the same time, a second light 204 containing a portion of another wave chain that does not interfere with the above wave chain is incident at an angle θ i The light is incident at this point. The light intensity of the combined light (intensity added light) reflected in the θ0 direction is cos 2 (πPθ0 / λ)+cos 2 {πP(θ0-θ i It is given by ) / λ}. For example, θ such that the light intensity of the second term is minimized when the light intensity of the first term is maximized. i Optimizing this value cancels out (averages or smooths) the maximum and minimum light intensities. As a result, spatial interference noise is significantly reduced.

[0372] In other words, by simultaneously irradiating the object to be measured 22 with the first light 202 and the second light 204, which are in a non-interfering (or low-interfering) relationship with each other, while changing their irradiation angles, optical interference noise (speckle noise) based on the spatial coherence of light can be reduced. In Figure 28A, for the sake of simplicity, the explanation is given using only the sum of the intensities of two lights 202 and 204 that are non-interfering (or low-coherent) with each other. However, it is not limited to this; three or more (or four or more) types of lights 202, 204, and 206, which are in a non-interfering relationship with each other, may also be simultaneously irradiated onto the object to be measured 22 while changing their irradiation angles. Increasing the number of lights that are non-interfering (or low-coherent) with each other increases the average number of optical interference noise (speckle noise), and therefore increases the interference noise reduction effect.

[0373] Critical illumination and Koehler illumination are generally known as methods for illuminating the object to be measured 22. To effectively reduce interference noise, it is desirable that multiple non-coherent (or low-coherent) lights 202, 204, and 206 overlap and illuminate the same arbitrary location within the object to be measured 22. Therefore, in this embodiment, it is preferable to use Koehler illumination as the method for illuminating the object to be measured 22.

[0374] In this embodiment, the initial light 200 emitted from the light-emitting unit 470 is divided to generate light 202, 204, and 206 (light containing different wave chains, as explained in the previous chapter) that are in a non-interfering (or low-interfering) relationship with each other. If amplitude division is used as the method for dividing the initial light 200 at this time, it is difficult to increase the number of divisions. Therefore, in this embodiment, by using the wavefront division method to divide the initial light 200, it is possible to increase the number of divisions into light 202, 204, and 206 that are in a non-interfering (or low-interfering) relationship with each other.

[0375] As described above, by tilting the propagation directions of light 202, 204, and 206, which are in a non-interfering (or low-interfering) relationship with each other, optical interference noise (speckle noise) based on the spatial coherence of light can be efficiently reduced. Specific examples of embodiments for tilting the propagation directions of light 202, 204, and 206, which are in a non-interfering (or low-interfering) relationship, are described sequentially below.

[0376] Figure 28B shows an example of a method for reducing optical interference noise using a single-core multimode optical fiber. Figure 28B(a) shows the characteristics of the emitted light 1044 when the incident light 1042 is focused to the center of the incident surface of the optical fiber core region or optical guides 330 / 332 / 340.

[0377] In the state shown in Figure 28B(a), most of the light in the incident light 1042 travels in a straight line through the core region of the optical fiber or the central part of the optical guides 330 / 332 / 340. As a result, the intensity distribution of the emitted light 1044 shows the highest intensity in the direction along the optical axis center on the emission surface, exhibiting an almost axially symmetric intensity characteristic. When the central position on the emission surface within the core region of the optical fiber or the optical guides 330 / 332 / 340 is aligned with the front focal point of the collimating lens 318, the emitted light 1044 after passing through the collimating lens 318 becomes parallel light. The direction of propagation of this parallel light coincides with the optical axis of the collimating lens 318.

[0378] Figure 28B(b) shows the characteristics of the emitted light 1044 when the incident light 1042 is focused on the outer side of the incident surface of the optical fiber core region or optical guide 330 / 332 / 340 (i.e., close to the cladding region 334). In this case, much of the light in the incident light 1042 undergoes multiple reflections near the interface between the optical fiber core region or optical guide 330 / 332 / 340 and the cladding region 334. As a result, the intensity distribution of the emitted light 1044 from the optical fiber core region or optical guide 330 / 332 / 340 tends to be a "donut-shaped intensity distribution," for example, with low intensity in the center and high intensity around the periphery.

[0379] The core diameter of a single-core multimode optical fiber is often larger than that of a single-mode optical fiber. For example, while the core diameter of a single-mode optical fiber is typically 3 μm to 5 μm, the core diameter of a multimode optical fiber is often between 30 μm and 2000 μm (for example, 220 μm or 600 μm as standard sizes). Therefore, after passing through the collimating lens 318, the emitted light 1044 from the peripheral part of the core of the multimode optical fiber has its direction of propagation tilted by θ with respect to the optical axis of the collimating lens 318. By changing the focal insertion position of a single-core multimode optical fiber in this way, the direction of propagation after passing through the collimating lens 318 changes, and optical interference noise is reduced.

[0380] In reality, within an optical fiber, the data should be analyzed using wave optics, specifically as the light intensity distribution mode in the cross-section of the core region, rather than using geometric optics. However, for the sake of explanation, Figure 28B uses the difference in optical paths passing through the core region of the optical fiber or through the optical guides 330 / 332 / 340 for illustrative purposes.

[0381] As described above, optical waves 202, 204, and 206, which have a non-coherent (or low-coherent) relationship with each other, may be passed through a waveguide element (such as an optical fiber, optical guide, or optical element with a structure in which optical waveguides are integrated on the same substrate) that allows for multimode conversion of internal traveling waves, and the light emitted from the waveguide element may be used to illuminate the object to be measured 22 with Keller illumination. Using Keller illumination in this way makes it easy to simultaneously illuminate the same point on the object to be measured 22 with non-coherent (or low-coherent) optical waves 202, 204, and 206 with different irradiation angles. As a result, optical interference noise can be easily reduced.

[0382] Incidentally, the above method is also effective in reducing optical interference noise that appears in spectral characteristics mainly due to the temporal coherence of light. In Figure 28B(a) and Figure 28B(b), the optical paths passing through the core region of the optical fiber or within the optical guides 330 / 332 / 340 are different. This is thought to be because the phase distribution contained in the emitted light 1044 is significantly different in Figure 28B(a) and Figure 28B(b).

[0383] Figure 28C shows an application example of the optical interference noise reduction method described in Figure 28B. An optical property conversion element 210 formed of a light-transparent material with refractive index n constitutes a first region 212 and a second region 214. When the difference in the optical path lengths between the two regions becomes greater than the aforementioned coherence distance ΔL0 (or twice that distance), the degree of partial coherence between the first light 202 and the second light 204 that have passed through regions 212 and 214 respectively is significantly reduced.

[0384] By giving different slope angles between the incident and exit surfaces in each region 212 and 214, the exit angles between the first light 202 and the second light 204 will differ when the incident angle of the initial light 200 is the same. Therefore, by optimizing the exit angles between the first light 202 and the second light 204, which are non-interfering (or have low coherence) with each other, the optical interference noise reduction explained in Figure 28B can be efficiently performed.

[0385] Here, the difference in the emission angles of the two is represented by θ. Immediately after this, a focusing lens 314 with a focal length F is placed, and the incident surface of the optical fiber core region or optical guide 330 / 332 / 340 is aligned with the rear focal plane of this focusing lens 314. As a result, the focusing positions of the two are shifted by Fθ on the incident surface of the optical fiber core region or optical guide 330 / 332 / 340.

[0386] Let W represent the width within the fiber core region or optical guide 330 / 332 / 340. If the difference in the focusing positions Fθ between the two exceeds W, the amount of light entering the fiber core region or optical guide 330 / 332 / 340 from either the first light 202 or the second light 204 will be significantly reduced. Therefore, it is desirable to satisfy the condition Fθ ≤ W.

[0387] According to the theory of optical diffraction, light beams 202 and 204 at the focal point have a predetermined spread. Therefore, even under the condition Fθ > W, some of both beams will enter the fiber core region or the optical guides 330 / 332 / 340. Thus, the minimum essential condition is that Fθ > W / 2.

[0388] As shown in Figure 28B, it is desirable that the optical paths within the fiber core region or optical guides 330 / 332 / 340 be different between the first optical fiber 202 and the second optical fiber 204, which are non-interfering (or have low coherence) with each other. The condition for the two optical paths to be different is that Fθ ≤ W / 1000 (preferably Fθ ≤ W / 1000).

[0389] To summarize the above explanation, the range of the angle θ between the first light 202 that passed through the first region 212 and the second light 204 that passed through the second region 214 is W / (100F) ≤ θ ≤ W / (2F) (preferably W / (1000F) ≤ θ ≤ W / F).

[0390] As an application example of this embodiment, instead of using a single-core fiber, a bundled fiber 1040 may be used. Figure 28D(a) shows an application example using a bundled fiber 1040. The light source unit 2 consists of a light-emitting unit 470 and an optical characteristics control unit 480. The first light 202 and the second light 204, which are non-interfering (or have low coherence) with each other, are irradiated onto the object to be measured 22 by the Keller illumination system 1026. The focal length of the collimating lens 318 installed in the Keller illumination system 1026 controls the difference in irradiation angle between the first light 202 and the second light 204 irradiated onto the object to be measured 22. If the focal length of the collimating lens 318 is short, the difference in irradiation angle between the two will be large.

[0391] Within the optical characteristic conversion element 210 located in the optical characteristic control unit 480, the thickness differs between the first region 212 and the second region 214. When the optical path length between the two exceeds the coherence distance ΔL0 (or twice that distance), the coherence between the first light 202 and the second light 204 decreases.

[0392] The focusing lens 314 focuses the first and second light rays 202 and 204 onto the incident surface of the bundle fiber 1040. Here, the first light ray 202 and the second light ray 204 each enter different core regions within the bundle fiber 1040. The combination of this difference in the core regions they pass through and the collimating lens 318 changes the direction of propagation between the light rays 202 and 204 exiting the bundle fiber 1040.

[0393] Figure 28D(b) shows an optical system in which a phase characteristic conversion element 1050 is placed directly in front of the incident surface of the bundle fiber 1040, compared to Figure 28D(a). The first and second light rays 202 and 204 that pass through this phase characteristic conversion element 1050 have their phase characteristics converted and enter the bundle fiber 1040. Specifically, this phase characteristic conversion element 1050 may be a diffuser plate with a microstructure on its surface, such as frosted glass. However, it is not limited to this, and a grating, hologram element, Fresnel zone plate, etc., may also be used.

[0394] At the beginning of this chapter, it was explained that changing the irradiation angle relative to the object being measured 22 is the most effective way to reduce interference noise caused by spatial coherence. However, experiments have confirmed that differences in the phase distribution between mutually non-interfering (or low-interfering) light sources 202 and 204 are also effective in reducing interference noise caused by spatial coherence. In other words, the experimental results showed that the optical system in Figure 28D(b) was more effective in reducing interference noise caused by spatial coherence than the optical system in Figure 28D(a).

[0395] In Figure 28D(c), the phase characteristic conversion element 1050 is positioned near the focusing surface of the first light 202 and the second light 204, compared to Figure 28D(b). In Figures 28D(a) and 28D(b), the first light 202 and the second light 204 mainly pass through different core regions within the bundle fiber 1040 separately. In contrast, in Figure 28D(c), the first light 202 and the second light 204 mix together when passing through the phase characteristic conversion element 1050. As a result, the first light 202 and the second light 204 pass through the same core region within the bundle fiber 1040.

[0396] Figure 28E shows another embodiment of this design. As a method of overlapping and irradiating the light-illuminated object 1030 with light 202, 204, and 206 that have passed through different regions 212, 214, and 216 while changing the irradiation angle, a phase characteristic conversion element 1050 such as a diffuser plate is used. The surface of the phase characteristic conversion element 1050 has a fine uneven shape, which diffuses the light that passes through it. The irradiation angle at an arbitrary position on the light-illuminated object 1050 changes to θ1, θ2, and θ3 for the first light 202, the second light 204, and the third light 206. At the same time, the first light 202, the second light 204, and the third light 206 overlap and irradiate at this position.

[0397] Because each light source has a different illumination angle, the patterns of optical interference noise (speckle noise) that appear on the illuminated object 1050 differ between the first light source 202, the second light source 204, and the third light source 206. Since the first light source 202, the second light source 204, and the third light source 206 are in a non-interfering (or low-interfering) relationship, the different optical noise patterns mix together on the illuminated object 1030. As a result, the optical noise patterns are averaged (smoothed), and the overall interference noise is reduced.

[0398] Figure 28F shows an application example of this embodiment. In Figure 28F, light 202, 204, and 206, which are non-interfering (or low-interfering) with each other, are focused at spatially different positions. When the Keller illumination system 1026 is used as the illumination system for the light-illuminated object 1030, the light 202, 204, and 206 focused at these different positions mix (overlap) with each other and illuminate any position within the light-illuminated object 1030. Also, the illumination angles at this time are different for each other. As a result, the optical interference noise pattern (speckle noise pattern) is averaged (smoothed), and the overall optical interference noise (speckle noise) is reduced.

[0399] As a method for focusing the mutually non-interfering (or low-interfering) light beams 202, 204, and 206 at spatially different positions, Figure 28F uses a fly-eye lens 1028 in which multiple lenses with optical axes are arranged in the same space. In Figure 28F(a), this fly-eye lens 1028 is placed immediately after the optical characteristic conversion element 210. In Figure 28F(b), this fly-eye lens 1028 is placed immediately before the optical characteristic conversion element 210 and is integrally formed with the optical characteristic conversion element 210.

[0400] In both Figure 28F(a) and Figure 28F(b), the third, second, and first light beams 206, 204, and 202, having individually passed through the third, second, and first regions 216, 214, and 212, respectively, are focused at positions α, β, and γ. With the adoption of the Keller illumination system 1026, the light beams 206, 204, and 202, after passing through each focusing position, mix together and illuminate the light-illuminating object 1030 with different illumination angles.

[0401] In the example shown in Figure 28F, a fly-eye lens 1028 is used to focus the light passing through different regions 216, 214, and 212 to different positions α, β, and γ, respectively. However, this is not the only method, and the light may be focused to different positions α, β, and γ by any other method. As another example of an embodiment, a liquid crystal lens array may be used instead of the fly-eye lens 1028.

[0402] Figure 28G shows the experimental results of the effect verification that were actually performed. The horizontal axis of Figure 28G represents the movement position of the surface of the object being measured 22. The vertical axis of Figure 28G represents the light intensity that appeared on the camera's image sensor. A diffuser plate with an Ra value (a value of average roughness) of 2.8 μm, which represents the average height of the surface irregularities, was used as the object being measured 22.

[0403] Figure 28G(a) shows the optical interference noise pattern when conventional light passing through the core region of a single-core optical fiber or the central part of the optical guides 330 / 332 / 340 is irradiated onto the object to be measured 22. In Figure 28G(a), there is a large fluctuation in light intensity and a large optical interference noise (speckle noise) is present.

[0404] Figure 28G(b) shows the optical interference noise pattern when the optical system in Figure 28D(b) is used. The optical conversion element 210 is made of quartz glass and consists of 48 segments, each with a thickness of 1 mm. The phase characteristic conversion element 1050 uses a diffuser plate with an Ra value of 0.5 μm. The bundle fiber 1040 is 1.5 m long and consists of 320 strands of a single core with a diameter of 230 μm (NA (numerical aperture) 0.22) bundled together within a diameter of 5 mm. The focal lengths of both the condensing lens 314 and the collimating lens 318 are set to 50 mm.

[0405] Compared to Figure 28G(a), Figure 28G(b) shows a significant reduction in optical interference noise (speckle noise).

[0406] Chapter 13: Containers and measurement optical systems that accommodate diverse object shapes and measurement areas. Figure 29A(a) shows an example of a container structure for holding the object to be measured 22 in this embodiment. In this embodiment, the container is provided that can measure not only solids but also liquids and gases under the same conditions with good reproducibility. When the object to be measured 22 is a liquid or gas, the measurement data changes significantly depending on the change in the thickness t3 of the object to be measured installation area 1052 in which it is set. To address this, in this embodiment, the container has a structure in which the thickness t3 of the object to be measured installation area 1052 can be determined to be constant. Specifically, the container has a structure in which the object to be measured installation area 1052 is sandwiched between an upper light-transmitting member 1064 and a lower light-transmitting member 1062 via a spacer 1056 whose thickness t3 is strictly controlled. By adopting this simplified structure, it is possible to provide the container to the user at a very low cost, and it has the effect of accurately reproducing the thickness t3 of the object to be measured installation area 1052.

[0407] Furthermore, as mentioned above, the holding container structure shown in Figure 29A(a) can be manufactured at very low cost, making it easy for users to "dispose of" it after each measurement. The optical device 10 shown in this embodiment requires very high-precision measurement. Therefore, if the same holding container is reused for different measurements, fragments of the previously measured object 22 will remain inside the container, and there is a risk that the measurement data detected from these fragments will degrade the accuracy of the current measurement. If the holding container can be "disposable" after each measurement, not only will the measurement accuracy improve, but user convenience will also be greatly enhanced.

[0408] The upper light-transmitting member 1064 and the lower light-transmitting member 1062 used in Figure 29A(a) or (b) should preferably be made of inorganic material. If the upper light-transmitting member 1064 and the lower light-transmitting member 1062 are made of organic material, the methyl groups and methylene groups contained in the organic material will greatly absorb light of a wavelength around 1.7 μm. Therefore, when measuring the spectral characteristics of the object to be measured 22 up to the wavelength range around 1.7 μm, it is not preferable to use organic material. In addition, commonly used blue plate glass and optical glass often contain a large amount of hydroxyl groups during manufacturing. Therefore, inorganic materials with a low amount of hydroxyl group content (for example, silicate glass, anhydrous glass, anhydrous quartz, etc.) are preferable for the upper light-transmitting member 1064 and the lower light-transmitting member 1062.

[0409] Both the upper light-transmitting member 1064 and the lower light-transmitting member 1062, in the areas adjacent to the measurement target installation area 1052, correspond to the light propagation path 6 through which the detection light passes. Therefore, to prevent the user from accidentally touching this area, the outer periphery of the lower light-transmitting member 1062 is integrated (bonded) with the outer periphery holding member 1066. The user moves the holding container by holding the outer periphery of the outer periphery holding member 1066. In this way, the outer periphery holding member 1066, which the user can directly touch, is formed outside the light propagation path 6 through which the light passes, improving user convenience.

[0410] As shown in Figure 29A, the inner diameter of the outer retaining member 1066 (the inner hole) is slightly wider than the outer diameter of the spacer 1056. Therefore, the thickness of the measurement target installation area 1052 can be accurately defined using only the thickness of the spacer 1056, without being affected by the thickness of the outer retaining member 1066.

[0411] Furthermore, a gap is provided between the inner side of the side wall of the outer holding member 1066 and the outer side of the upper light-transmitting member 1064, allowing a tool such as tweezers to be inserted into this gap. While supporting the outer circumference of the upper light-transmitting member 1064 with the tool inserted into this gap, the upper light-transmitting member 1064 can be moved up and down relative to the outer holding member 1066. This structure improves user convenience for the holding container. Here, user convenience can be ensured if the difference value 2S between the inner diameter of the side wall of the outer holding member 1066 and the outer diameter of the upper light-transmitting member 1064 is set to 1 mm or more and 2 cm or less (preferably 4 mm or more and 4 cm or less).

[0412] For example, if the object to be measured 22 is a liquid, the object to be measured installation area 1052 will be filled with the liquid. When the object to be measured installation area 1052 is sandwiched between the upper light-transmitting member 1064 and the lower light-transmitting member 1062 via a spacer 1056, there is a risk that some of the liquid will overflow and leak into the light propagation path 6. To prevent this risk, the structure is designed to allow for the placement of an excess substance absorbing member 1068 made of a highly absorbent material. Therefore, when the object to be measured installation area 1052 is sandwiched between the upper light-transmitting member 1064 and the lower light-transmitting member 1062 via a spacer 1056, this excess substance absorbing member 1068 absorbs the overflowing liquid. Due to the water-absorbing action of this excess substance absorbing member 1068, contamination of part of the light propagation path 6 caused by the overflowing liquid riding up onto the upper light-transmitting member 1064 can be prevented. As a result, stable and highly accurate measurements become possible.

[0413] If the inner diameter of the excess material absorbing member 1068 is made larger than the outer diameter of the spacer 1056, and the outer diameter of the excess material absorbing member 1068 is made smaller than the inner diameter of the side wall of the outer retaining member 1066, the excess material absorbing member 1068 can be properly installed on the inner upper surface of the outer retaining member 1066. Furthermore, if lint or dust comes out of the excess material absorbing member 1068, this lint or dust may be mismeasured, potentially degrading the measurement accuracy. Therefore, it is desirable to use a material that does not easily produce lint or dust (for example, nonwoven fabric, filter paper, or special paper used in clean rooms) as the material for the excess material absorbing member 1068.

[0414] Figure 29A(c) shows an example of a holding container structure used to obtain spectral data in the absence of the object to be measured 22. For example, when measuring the spectral characteristics of the object to be measured 22, it is common to take the ratio (difference on a logarithmic scale) between the spectral characteristics with and without the object to be measured 22. Therefore, first, spectral data is obtained in the absence of the object to be measured 22 using the holding container shown in Figure 29A(c). After that, spectral data from the object to be measured 22 is obtained in the holding container shown in Figure 29A(a).

[0415] The structure in Figure 29A(c) shows that a light-transmitting member 1054 of a predetermined thickness is installed inside the outer holding member 1066. As mentioned above, it is desirable that the materials for the upper light-transmitting member 1064 and the lower light-transmitting member 1062 be inorganic materials with a low amount of hydroxyl groups. However, some anhydrous quartz also contains some hydroxyl groups, and some light absorption occurs in the wavelength range around 1.4 μm when light passes through the upper light-transmitting member 1064 and the lower light-transmitting member 1062. Therefore, in this embodiment, it is desirable that the upper light-transmitting member 1064 and the lower light-transmitting member 1062 be made of exactly the same material, and that the light-transmitting member 1054 of the predetermined thickness shown in Figure 29(c) be made of the same material. Furthermore, in order to match the amount of absorption of wavelength light around 1.4 μm, for example, which is affected by the thickness, the thickness of the light-transmitting member 1054 of a predetermined thickness is preferably the sum of the thickness t1 of the lower light-transmitting member 1062 and the thickness t2 of the upper light-transmitting member 1064, t1+t2. Here, if the dimensional error between the sum of the thickness t1 of the lower light-transmitting member 1062 and the thickness t2 of the upper light-transmitting member 1064, t1+t2 and the thickness of the light-transmitting member 1054 of the predetermined thickness is 1 mm or less, or 0.2 mm or less (preferably 0.1 mm or less), high measurement accuracy can be ensured.

[0416] As will be described later, there are cases where the object to be measured 22 is composed of multiple different materials (different compositions), and it is desired to measure the spectral characteristics of only a specific material (specific composition) among them. In this case, spectral data obtained from materials (compositions) not to be measured hinders the measurement accuracy αa1. In this embodiment, in order to ensure high measurement accuracy, the characteristics of the hindering factor αa1 are extracted in advance 1004, and using this first extracted information, disturbance noise is reduced, and a second information extraction 1000 is performed regarding the spectral characteristics of only the specific material (specific composition) to be measured.

[0417] Figure 29A(b) shows an example of a holding container structure used to pre-extract information 1004 about the characteristics of the inhibiting factor αa1. It basically has the same structure as Figure 29A(a), except that the measurement target installation area 1052 is changed to a known substance installation area 1058. Many living organisms contain a large amount of water. Alternatively, when obtaining characteristic information of specific cells being cultured in a culture medium, information 1004 extracted from the culture medium itself is mixed in as disturbance noise. Therefore, the holding container structure for extracting spectral characteristic information of pure water or spectral characteristic information of the culture medium itself as information 1004 to be extracted in advance corresponds to Figure 29A(b). In other words, in this case, the known substance installation area 1058 is filled within the measurement target installation area 1052 in Figure 29A. Here, as with Figure 29A(a), the lower light-transmitting member 1062 and the known substance installation area 1058, and the upper light-transmitting member 1064 correspond to part of the light propagation path 6.

[0418] Figure 29B shows an example of the procedure for holding the object to be measured 22 in the holding container described above. As shown in Figure 29B(a), the outer holding member 1066 and the lower light-transparent member 1062 are pre-integrated (bonded). The user then places the spacer 1056 on top of this lower light-transparent member 1062.

[0419] Next, as shown in Figure 29B(b), the user places the excess material absorbing member 1068 on the outside of the spacer 1056 (inside the outer holding member 1066). Figure 29B(c) shows the state in which the spacer 1056 is placed on the lower light-transmitting member 1062 and the excess material absorbing member 1068 is placed on the inner upper surface of the outer holding member 1066.

[0420] If the object to be measured 22 is solid, it is placed inside the spacer 1056 by picking it up with tweezers or similar. Figure 29B(d) shows an example of how to place the object to be measured 22 when it is in a liquid state. In this case, an appropriate amount of the object to be measured 22 is injected inside the spacer 1056 using a pipette or injection needle.

[0421] Once the spacer 1056 is filled with the object to be measured 22, the upper light-transmitting member 1064 is gently placed on top. At this time, the excess material absorbing member 1068 absorbs any excess liquid that spills out from the gap between the spacer 1056 and the upper light-transmitting member 1064. This excess liquid absorption effect of the excess material absorbing member 1068 prevents the deterioration of measurement accuracy caused by excess liquid mixing into the light propagation path 6.

[0422] When measuring using transmitted light to the object to be measured 22, it is preferable to use the example of the holding container structure shown in Figure 29A. In contrast, Figure 29C shows an example of a holding container structure when measuring using reflected light from the object to be measured 22. In Figures 29C(a) and (b), the lower light-transmitting member 1062 used in Figures 29A(a) and (b) is not used, and instead a light-reflecting member 1070 with a light-reflecting film coated on its upper surface (upper one side) is used. Everything else is the same as in Figures 29A(a) and (b).

[0423] In Figure 29A(c), the upper and lower surfaces of the predetermined-thickness light-transmitting member 1054 have light-transmitting properties, and the light used for measurement passes through the upper and lower surfaces of the predetermined-thickness light-transmitting member 1054. In contrast, in Figure 29C(c), the upper surface of the predetermined-thickness light-transmitting member 1054 is the light-reflecting surface 1072. Also, the thickness of the predetermined-thickness light-transmitting member 1054 in Figure 29C(c) is the same as the thickness t2 of the upper light-transmitting member 1064.

[0424] In Chapter 10, when explaining the disturbance noise reduction method 1038 using Figure 26C, it was explained that the cause of disturbance noise generation 1036 differs slightly in the measurement target area 1032. In relation to that explanation, we will now describe an example of a measurement optical system used to comprehensively measure the overall characteristics of the object 22, and an example of a measurement optical system suitable for measuring the characteristics of only a local area within the object 22.

[0425] Figure 30A shows an example of a measurement optical system suitable for comprehensive measurement of the overall characteristics of the object to be measured 22. When measuring the overall characteristics of the object to be measured 22, it is desirable to collect and measure the entire detection light 1100 obtained from the entire object to be measured 22. As a specific example, in Figure 30A, initial incident light 1200 emitted from the light source unit 2 is uniformly irradiated onto the entire object to be measured 22, and the detection light 1100 obtained from the entire object to be measured 22 is collected and sent to the measurement unit 8. As a method for collecting the detection light 1100, in the embodiment example shown in Figure 30A, the light obtained from the entire object to be measured 22 is focused onto the entrance surface of the optical fiber 330 by a focusing lens 314.

[0426] In Figure 30A, a Keller illumination system is used as a method to uniformly irradiate the entire object 22 with initial incident light 1200 emitted from the light source unit 2. For example, initial incident light 1200 generated in the light source unit 2, which has an optical system structure as shown in Figure 16, is guided by an optical fiber 330 into the optical propagation path 6, which includes the object 22. The divergent light (initial incident light 1200) emitted from this optical fiber 330 is converted into parallel light by a collimating lens 318. By setting the size (luminous beam diameter) of this parallel light beam (initial incident light 1200) to be larger than the overall size of the object 22, a relatively uniform amount of light can be irradiated onto the object 22. Thus, Keller illumination is suitable for measuring the characteristics of the entire object 22.

[0427] As a method for placing the object to be measured 22 within the optical propagation path 6, using the object holding container 1080 shown in Figure 29A or Figure 29B improves user convenience. When measuring the optical properties of the object to be measured 22 with high precision, the measurement accuracy deteriorates if the user's fingerprints or dirt adhere to the surface of the object to be measured 22. As shown in Figure 29A or Figure 29B, the object to be measured 22 itself is housed inside the object holding container 1080, so the user does not directly touch the object to be measured 22 before or after measurement. In addition, the outer periphery of the outer holding member 1066, which the user directly touches, is located outside the optical propagation path 6. Therefore, the risk of deterioration in measurement accuracy due to handling of the object holding container 1080 can be avoided.

[0428] As an example of the application of Figure 30A, an element (e.g., a diffuser) for converting the phase characteristics of the initial incident light 1200 may be placed in the path of the parallel light beam (initial incident light 1200) just before it passes through the holding container 1080 of the object to be measured, thereby reducing the temporal coherence (a degree of temporal coherence) of the initial incident light 1200 itself. This makes it possible to implement a reduction measure L2 against optical interference noise generated by optical interference αc2 along the light propagation path 6.

[0429] Furthermore, as another application example of Figure 30A, an aperture limiting section 484 (e.g., an aperture) may be placed in the path of the parallel light beam (initial incident light 1200) before it passes through the holding container 1080 of the object to be measured. By applying aperture limiting in this way so that the initial incident light 1200 passes only through the object to be measured installation area 1052 within the holding container 1080 of the object to be measured, stray light contamination αc1 that occurs during measurement can be prevented.

[0430] Next, we will describe an example of a measurement optical system suitable for measuring the characteristics of only a local area within the object to be measured 22. In most cases, to measure the characteristics of only a local area within the object to be measured 22, an imaging lens 312 is used to form an imaging pattern for the object to be measured 22 on the surface of the image sensor 300.

[0431] Figure 30B(a) shows an example of an imaging optical system. Detection light 1100 emitted from point β within the object to be measured 22 is focused at point ε on the surface of the image sensor 300 by the action of an imaging lens 312 placed in the optical path. Similarly, detection light 1100 emitted from points α and γ within the object to be measured 22 is imaged at points ζ and δ on the surface of the image sensor 300. Therefore, by individually measuring the optical characteristics at each point δ, ε, and ζ on the surface of the image sensor 300, it becomes possible to measure the characteristics of each local region γ, β, and α within the object to be measured 22. In this way, by using the imaging optical system shown in Figure 30B(a), it becomes possible to easily measure the optical characteristics of the two-dimensionally arranged local regions α, β, and γ within the object to be measured 22.

[0432] However, when measuring the optical characteristics of each local region within the three-dimensional structure of the object to be measured 22, or when a light scatterer exists in the optical path of the detected light 1100 from the local region to the measurement unit 8 (e.g., the image sensor 300), the imaging optical system in Figure 30B(a) suffers a significant degradation in measurement accuracy due to the influence of stray light αc1. An example of a light scatterer existing in the optical path of the detected light 1100 is when measuring the activity of nerve cells in the brain using optical methods. The brains of higher animals, from reptiles onward, are covered by a skull. The inside of this skull has a relatively complex structure and therefore acts as a light scatterer.

[0433] The reason why measurement accuracy deteriorates due to light interference αc1 is explained below. Figure 30B(b) shows the optical path after passing through the imaging lens 312 of the detection light 1100 that originates from point η, which is closer to the imaging lens 312 than points α, β, and γ, which are arranged in a planar manner within the measurement target object 22 as described above. Since the detection light 1100 that originates from point η spreads on the surface of the image sensor 300, its influence on points δ, ε, and ζ on the surface of the image sensor 300 is relatively minor.

[0434] Figure 30B(c) shows the optical path of the detection light 1100 after it passes through the imaging lens 312, starting from point ξ, which is further from the imaging lens 312 than points α, β, and γ, which are arranged in a planar manner within the object 22 described above. The detection light 1100 starting from point ξ is focused just before the image sensor 300, illuminating the area around point ε. Consequently, the detection light 1100 starting from point ξ is mixed in as stray light αc1, degrading the measurement accuracy for point β of the object. For similar reasons, if a light scatterer is present in the optical path of the detection light 1100, a large amount of stray light αc1 will be mixed in when measuring the optical characteristics of a local measurement point β within the object 22.

[0435] Figure 30C shows an example of a measurement optical system suitable for high-precision measurement in a localized area that also includes the three-dimensional field within the object to be measured 22. Within the measurement unit 8, an imaging (confocal) optical system is formed for the measurement target position 1086 in the local three-dimensional direction within the object to be measured 22. An aperture limiting section 484 is provided at the imaging position or confocal position corresponding to the measurement target position 1086. This removes stray light αc1 from different depth positions η and ξ. As a specific example of the form of this aperture limiting section 484, a pinhole 1088 or a slit 350 may be used.

[0436] In the embodiment shown in Figure 30C, the divergent detection light 1100 that has passed through the pinhole 1088 or slit 350 (aperture limiting section 484) is first converted into parallel light by the collimating lens 318 before being incident on the spectroscopic element (e.g., a blazed grating) 320. The detection light 1100, which has been divided into measurement wavelengths by this spectroscopic element, is then focused onto the image sensor 300 by the condensing lens 314-2.

[0437] When a pinhole 1088 is used as the aperture limiting unit 484, the image sensor 300 is composed of line sensors arranged in one dimension. The intensity of the spectrally separated detection light 110 is measured for each cell on the line sensors. The spectral signal obtained from these line sensors (image sensor 300) is measured by the signal receiving unit 40 and transmitted to the signal processing unit 42.

[0438] On the other hand, when a slit 350 is used as the aperture limiting section 484, detection light 1100 emitted from multiple local measurement target positions 1086 (for example, the positions α to γ ​​in Figure 30B) arranged in a line on the same plane within the object to be measured 22 passes through the slit 350 simultaneously. In the diagram shown in Figure 30C, in this case, the multiple local measurement target positions 1086 arranged in a line on the same plane within the object to be measured 22 are projected in the vertical direction within the image sensor 300, and the spectral characteristics of each local measurement target position 1086 (for example, the spectral characteristics of the α, β, and γ points in Figure 30B) are measured in the horizontal direction within the image sensor 300.

[0439] The detection light 1100, which is in a divergent state from the measurement target position 1086 within the object to be measured 22, becomes a parallel light state in the objective lens 1090. This parallel light state detection light 1100 is reflected by the polygon mirror 1082 and the galvano mirror 1084, respectively, and then imaged by the converging lens 314-1.

[0440] In the embodiment shown in Figure 30C, the measurement target position 1086 coincides with the front focal position of the objective lens 1090. Therefore, changing the distance between the objective lens 1090 and the object to be measured 22 changes the measurement target position 1086 in the Z direction. Furthermore, the tilt angle of the light-reflecting surface of the galvanic mirror 1084 changes the measurement target position 1086 in the Y direction. And further, the rotation of the holingon mirror 1082 changes the measurement target position 1086 in the X direction. In this way, it becomes possible to measure the spectral characteristics at any local measurement target position 1086 in the three-dimensional direction within the object to be measured 22.

[0441] For example, let's take the case of measuring changes in spectral characteristics at different local locations within the brain in relation to biological activity in the brain of higher animals, such as reptiles. The detection light 1100 measured by the measurement unit 8 needs to pass through the skull. The inside of the skull has a relatively complex structure and acts as a light scatterer for the detection light 1100. Furthermore, the scattering angle range of the detection light scattered within the light scatterer is very wide. Therefore, the detection light 1100 after passing through the light scatterer is a mixture of light obtained from multiple different locations, acting as stray light contamination αc1.

[0442] A characteristic of light passing through a light scatterer is that some of the light traveling through the light scatterer travels in a straight line within it. Therefore, if only the detection light 1100 traveling in a straight line within the light scatterer can be collected and measured, measurement through the light scatterer becomes possible. Specifically, by using a detection optical system such as that shown in Figure 30C, which has an aperture limiting section 484 at the imaging (consfocal) position to measure the optical characteristics of a local measurement target position 1088 within the object to be measured 22, the intrusion of stray light αc1 from other positions within the object to be measured 22 can be reduced.

[0443] The primary cause of the decrease in the intensity of straight-traveling light within the light scatterer is the "cancellation phenomenon of straight-traveling light intensity due to phase shifts between straight-traveling light beams." When the wavelength of the detected light 1100 increases, the effect of this cancellation phenomenon on the same amount of phase shift decreases, improving the measurement accuracy through the light scatterer. Therefore, near-infrared light with a wavelength of 750 nm or more exhibits less decrease in the intensity of straight-traveling light within the scatterer than visible light with a wavelength of 700 nm or less. On the other hand, a large amount of cerebrospinal fluid (CSF) exists directly beneath the skull. The water component in this CSF significantly absorbs infrared light with a wavelength of 2 μm or more. Therefore, when measuring the spectral characteristics of local locations within the brain through the skull, using near-infrared light with a wavelength range of 750 nm to 2 μm (preferably 850 nm to 1.85 μm) improves measurement accuracy.

[0444] In this embodiment, if the object to be measured 22 is an animal or the like, the measurement system shown in Figure 20A may be used, for example. Alternatively, at least a part of the object to be measured 22 (the part including the measurement target position 1086) may be fixed in some way. On the other hand, if the object to be measured 22 is a relatively small solid, or contained in a liquid or gas, it may be held in the object holding container 1080 described in Figures 29A to 29C and measured.

[0445] Chapter 14: Method for Reducing Optical Disturbance Noise Using Extracted Information As already explained using Figure 26C, the causes of optical disturbance noise 1036 differ slightly depending on the measurement target area 1032. Taking this into consideration, Chapter 13 describes examples of measurement optical systems suitable for each measurement target area 1032. Furthermore, the causes of optical interference noise and examples of countermeasures were explained in Chapters 12 and earlier. In this chapter, we will explain examples of methods to reduce the influence of optical disturbance noise using methods other than the optical interference noise reduction described above. Specifically, we will reduce disturbance noise using the first extracted information already explained in Figure 26A and perform the second information extraction 1000. This will enable high-precision measurement. Note that the embodiment examples already explained in Chapter 13 may be used as the measurement optical system and the method for holding the measurement target object 22 used in this chapter.

[0446] Figure 31A shows various forms of optical disturbance noise generated by interaction with light inside the object being measured 22. The initial incident light 1200 undergoes various interactions inside the object being measured 22. The effects of these various interactions then appear in the detected light 1100 obtained from the object being measured 22. In other words, the effects of these various interactions are mixed into the detected light 1100 as optical disturbance noise.

[0447] First, let's explain the case where the object to be measured 22 has a complex composition. For example, most living systems are composed of carbohydrates, lipids, proteins, and nucleotides, and also contain a lot of water. Therefore, even if we try to measure the optical properties of only the proteins in a living organism, the optical properties of water will be mixed into the measurement data.

[0448] Infrared spectroscopy, near-infrared spectroscopy, Raman spectroscopy, and fluorescence / phosphorescence spectroscopy all analyze the composition of an object 22 using its light absorption characteristics (absorbance) of specific wavelengths of light. Consequently, the influence of light absorption αa1 of other components is introduced as optical disturbance noise.

[0449] Figure 31A(a) shows the influence of light absorption αa1 of other components when attempting to measure the wavelength-specific light absorption characteristics of only component ζ1092 within the object 22. For example, consider a case where the absorbance of component ζ1092 to be measured is low (hardly absorbs light) at a specific wavelength, while the absorbance of another component ξ1096 at the same specific wavelength is high (absorbs a large amount of light). When initial incident light 1200 with a specific wavelength is irradiated, a large amount of the specific wavelength light is absorbed by the other component ξ1096 within the object 22. As a result, the intensity of the specific wavelength light contained in the detected light 1100 obtained from the object 22 decreases significantly.

[0450] The right side of Figure 31A(b) shows an example of the effect of the light scattering characteristic αa2 of light passing through the interior of component ζ1092. The physical wavelength of light is inversely proportional to the refractive index of the medium through which the light passes. Depending on the refractive index inside component ζ1092, the physical wavelength of light passing inside and outside component ζ1092 differs. Therefore, if a phase difference occurs between the light after passing through component ζ1092 and the light traveling in a straight line outside component ζ1092, they interfere with each other, and the amount of light traveling in a straight line decreases. This phenomenon occurs not only when component ζ1092 exists alone in the air, but also when component ζ1092 is dispersed in an aqueous solution.

[0451] The left side of Figure 31A(b) shows the effect of optical diffraction and optical interference αb2 that occurs when the surface of component ζ1092 has minute irregularities. When the phase of light changes between the convex parts μ and concave parts κ on the surface of component ζ1092, they interfere with each other, and the amount of light traveling in a straight line decreases.

[0452] Figure 31A(c) shows an example of the influence of light reflection and light interference characteristics αa3. For example, consider the case where the upper surface σ and lower surfaces ν and ω of the constituent component ξ1096 are flat and parallel to each other. Most of the light that passes inside the constituent component ξ1096 passes through the lower surface ν. However, some of the light is reflected by the lower surface ν and returns to the interior of the constituent component ξ. Then, after being reflected by the upper surface σ of the constituent component ξ1096, it passes through the lower surface ω and exits the constituent component ξ1096. Then, light interference occurs between the light that passed through the lower surface ν and the light that passed through the upper surface σ and then the lower surface ω, and the effective amount of light transmitted changes.

[0453] Figure 31A(d) shows the effect of another example of light scattering αa2 at component η1098 contained within the object being measured 22. When light scattering αa2 occurs at component η1098, the amount of light transmitted in a straight line decreases. On the other hand, most of the light bends in a direction that deviates significantly from the incident direction of the initial incident light 1200. Thus, a wide variety of optical interactions occur inside the object being measured 22.

[0454] In Figure 31A(a), the light is affected by the light absorption of another component, ξ1096. However, in the other effects shown in Figures 31A(b) to (d), while there is a decrease in the light intensity of the straight-traveling light that propagates in the same direction as the initial incident light 1200 within the detected light 1100, there is no light absorption phenomenon. Therefore, this decrease in the light intensity of the straight-traveling light can be called "light intensity attenuation." Furthermore, the spectral characteristics or spectral characteristic signal of the detected light 1100 obtained by this phenomenon can also be called the light intensity attenuation spectral characteristics or light intensity attenuation spectral characteristic signal.

[0455] This section explains the relationship between the various optical interactions described here and the optical disturbance noise reduction method explained in Figure 26A. First, we will take the example shown in Figure 31A(a) in which the inside of the object being measured 22 is composed only of constituent components ξ1096 and ζ1092, and explain its relationship with Figure 26A.

[0456] In this case, spectral characteristic information obtained from the other component ξ1096 (absorbance information of the other component ξ1096 alone) is used as the first extracted information 1004. Specifically, the spectral characteristic signal of the detected light 1100 obtained from the object to be measured 22, which is composed only of component ξ1096, is collected in advance, and the absorbance information (or absorbance rate information) of the other component ξ1096 alone is extracted 1004 in the signal processing unit 42. Then, using this first extracted information (absorbance information of the other component ξ1096 alone), the absorbance information (or absorbance rate information) of component ζ1092, which corresponds to the unknown second information, is extracted 1000. Specifically, the spectral characteristic signal of the detected light 1100 obtained from the object to be measured 22, which contains both component ξ1096 and component ζ1092, is collected in the measurement unit 8. The signal processing unit 42 then subtracts the absorbance information or absorbance rate information (first extracted information) of the other known component ξ1096 alone from the spectral characteristic signal which includes both component ξ1096 and component ζ1092, and extracts the absorbance information or absorbance rate information (second extracted information 1004) of only component ζ1092.

[0457] Next, a method for extracting absorbance information or absorbance information (second extracted information 1004) of only the constituent component ζ1092 will be explained in detail. The spectral characteristic signal obtained by subtracting the absorbance information or absorbance information (first extracted information) of the other known component ξ1096 alone from the spectral characteristic signal containing both constituent components ξ1096 and ζ1092 includes the interaction effects shown in Figures 31A(b) to (d). Therefore, in this embodiment, it is necessary to sequentially remove the interaction effects shown in Figures 31A(b) to (d) from the above spectral characteristic signal to extract absorbance information or absorbance information (second extracted information 1004) of only the constituent component ζ1092.

[0458] By the way, it is difficult to individually measure the degree of influence of the interactions shown in Figures 31A(b) to (d). Therefore, in this embodiment, signal optimization processing is performed on the spectral characteristic signal to automatically extract a correction curve in which the influences of the interactions shown in Figures 31A(b) to (d) are mixed. This correction curve is extracted 1004 from the spectral characteristic signal that includes the influences of the interactions shown in Figures 31A(b) to (d). The signal processing unit 42 performs this information extraction 1004 process for the correction curve. In this signal processing (data processing) step, the information of the correction curve in which the influences of the interactions shown in Figures 31A(b) to (d) are mixed corresponds to new first extracted information 1004. Then, the above correction curve information (first extracted information) is deleted from the spectral characteristic signal in which the influences of the interactions shown in Figures 31A(b) to (d) are mixed, and absorbance or absorbance characteristic information of the constituent component ζ1092 alone, which has high measurement accuracy, is extracted. This signal processing (data processing) step itself corresponds to process 1000, which uses the first extracted information (correction curve information) to reduce the optical disturbance noise generated by the interaction shown in Figures 31A(b) to (d), and performs a second information extraction (extraction of absorbance characteristic information of the constituent component ζ1092 alone, which has high measurement accuracy).

[0459] The interaction effect shown in Figures 31A(b) to (d) appears mainly in the baseline profile change within the spectral characteristic signal obtained by subtracting the absorbance information or absorbance information (first extracted information) of the other known component ξ1096 alone from a spectral characteristic signal containing both constituent components ξ1096 and ζ1092. Therefore, the optical disturbance noise reduction process using the correction curve information performed in this embodiment may also be called "baseline correction".

[0460] In the above explanation, for the sake of clarity, an example of an embodiment was described in which baseline correction was performed after removing the influence of absorbance (absorption rate) information 1004 of other component ξ1096. However, the explanation is not limited to this, for example, if the object to be measured 22 is composed only of component ζ1092, baseline correction may be performed directly on the spectral characteristic signal obtained from the measurement unit 8 (and signal receiving unit 40).

[0461] Figure 31B shows the relationship between absorbance (or absorbance rate) characteristic information obtained when using near-infrared light with a wavelength range of 750 nm to 2 μm (preferably 850 nm to 1.85 μm) and the measurement target. The first harmonic region, the combined tone region, and the second harmonic region of the vibrational mode 982 of the functional group (atomic group) containing hydrogen atoms that make up the molecule absorb the above near-infrared light.

[0462] The first harmonic region of the functional group containing hydrogen atoms that make up the molecule absorbs light mainly in the range of 1.37 μm to 1.8 μm, with wavelength 980. Compared to the combined tone region and the second harmonic region, the amount of light absorbed here is relatively large. Furthermore, the wavelength range of absorption differs for each biological component 988, and the corresponding biological component 988 can be predicted from the value of the wavelength at which absorption is greatest (the central wavelength of the absorption band).

[0463] Specifically, carbohydrates are most absorbed by light around 1.6 μm (1.55 μm to 1.65 μm). Lipids, on the other hand, absorb light between 167 μm and 1.8 μm. Furthermore, among lipids, saturated fatty acids (1.7 μm to 1.8 μm) absorb more light at wavelengths longer than unsaturated fatty acids (1.63 μm to 1.73 μm). From this characteristic, the degree of unsaturation (the proportion of unsaturated fatty acids) within a lipid can be estimated to some extent.

[0464] Functional group vibrations, caused by the vibration of hydrogen atoms bonded to nitrogen atoms within proteins, absorb light in the 1.43 μm to 1.55 μm range. Protein structures with unique structures (secondary structures), such as the helical α-helix and the folded β-sheet, absorb light in the 1.5 μm to 1.6 μm range. Basic amino acids absorb light in the 1.43 μm to 1.52 μm range. Among basic amino acids, the absorption wavelengths, in descending order of shortest to longest, are lysine, arginine, and histidine.

[0465] The absorption wavelength range of proteins shown in Figure 31B merely represents the range of functional group vibrations caused by the vibration of hydrogen atoms bonded to nitrogen atoms; the actual absorption wavelength range of proteins is much broader. This is because alanine, an amino acid, contains a methyl group (included in the lipid range), and serine contains a hydroxyl group (included in the water absorption range), so their absorption bands also appear.

[0466] The combined tone region absorbs light mainly in the range of 1.14 μm to 1.45 μm with a wavelength of 980, and the amount of light absorbed is smaller compared to the first harmonic region. The second harmonic region absorbs light mainly in the range of 0.95 μm to 1.25 μm with a wavelength of 980, and the amount of light absorbed is even smaller compared to the first harmonic region. Within this second harmonic region, the light absorption wavelength range for lipids is 1.10 μm to 1.25 μm, for carbohydrates it is 1.06 μm to 1.14 μm, and for proteins it is 0.94 μm to 1.10 μm.

[0467] As shown in Figure 31B, the amount of light absorption is greatest in the first harmonic region and least in the second harmonic region. Therefore, in the spectral characteristics information after baseline correction, the maximum absorbance in the first harmonic region is greater than the maximum absorbance in the second harmonic region and the combined tone region. This characteristic can be used to predict the correction curve. In other words, baseline correction may be performed so that the maximum absorbance in the first harmonic region is greater than the maximum absorbance in the second harmonic region and the combined tone region.

[0468] In this embodiment, the above features may be used to optimize the correction curve to match the lower envelope in the second harmonic region (0.95 μm to 1.25 μm) or the short wavelength region (0.90 μm to 1.35 μm, preferably 0.95 μm to 1.32 μm) within the light intensity attenuation spectral characteristics (light intensity attenuation spectral characteristics) before baseline correction.

[0469] As Figure 31B shows, the light absorption of water (pure water) is very large in the wavelength range of 1.3 μm to 1.8 μm. While water (pure water) also absorbs light in the wavelength range of 0.88 μm to 1.3 μm, it is relatively smaller than in the above range. As components of biological systems, the wavelength ranges in which proteins, carbohydrates, and lipids absorb light significantly (or the central wavelengths of their respective absorption bands) were relatively separated across different wavelength values. However, the wavelength range in which water (pure water) absorbs light significantly overlaps with the above wavelength ranges.

[0470] Water makes up the majority of the composition of each component that constitutes a living system. Therefore, when a living organism is used as the object of measurement 22, the spectral characteristic signal of pure water accounts for the majority of the spectral characteristic signal obtained from the detected light 1100. This situation is explained by the example in Figure 31A(a). Proteins, carbohydrates, lipids, and nucleotides are included as constituent components ζ1092 of some living organism. However, because the water content, which corresponds to the other constituent components ξ1096 of the living organism, is overwhelmingly large, the spectral characteristic information corresponding to constituent component ζ1092 is buried in the spectral characteristic information of pure water. In this case, it is necessary to remove the absorbance characteristic component of water (spectral characteristic information corresponding to the first extracted information 1004) from the spectral characteristic signal obtained from the measurement unit 8 (or signal receiving unit 40).

[0471] In the life sciences, cell culture methods using culture media are widely employed. Therefore, real-time monitoring of the cell culture status within the culture medium is required. To address this requirement, this embodiment demonstrates the following: 1. Pre-extract the spectral characteristics information (first extraction information) of the culture medium alone. 2. Measure the cells in culture in each culture medium. 3. Spectral characteristic information of the culture medium alone, extracted in advance from the spectral characteristic signals obtained from cells in the culture medium. This is used to extract spectral characteristic information (second extraction information) from cultured cells. Signal processing (data processing) 1000 can be performed using the following procedure.

[0472] Here, we extend the concept of "solvent" as it is when a solute dissolves in a solvent to form a solution. For example, as described above, with regard to cultured cells in a culture medium, we broadly define the cultured cells as a type of solute and the culture medium as a type of solvent. The culture medium contains various nutrients necessary for cell culture, and for convenience, we broadly define the entire culture medium, including these various nutrients, as a "water-containing solvent." Furthermore, we consider biomolecules such as proteins, carbohydrates, lipids, and nucleotides as a type of solute, and for convenience, we broadly define the water system contained in living organisms as a "water-containing solvent."

[0473] In the signal processing method (data processing method) 1000, which consists of a series of processes described in Figure 26A, "using the first extracted information to reduce disturbance noise and extract second information," an example of the signal processing method (data processing method) 1000 when the first extracted information relates to "a solvent containing water" is described below.

[0474] The spectral characteristic signal obtained by the measurement unit 8 or the signal receiving unit 40 is given in the form of a collection of detection intensity (detected light quantity) data for each measurement wavelength of detected light 1100. The signal processing unit 42 converts this spectral characteristic signal into a light quantity attenuation characteristic signal for each measurement wavelength within the object to be measured 22 using a method described later.

[0475] In the first information extraction step 1004 preceding the measurement, absorbance (or absorbance rate) characteristic information of the "water-containing solvent" is acquired in advance. Then, for the above light intensity attenuation characteristic signal, a subtraction process is performed for each measurement wavelength by multiplying the absorbance (absorbance rate) characteristic information of the "water-containing solvent" by a predetermined coefficient.

[0476] In the absorbance (or absorbance) characteristic information for "water-containing solvents," the absorbance (absorbance) reaches its m...

Claims

1. In a light utilization device capable of measuring the absorbance characteristics of only the first component from a first object composed of a first component and a second component, The aforementioned optical utilization device includes a light source unit, a measurement unit, and a signal processing unit. The light source emits a first light to illuminate the first object to be measured. The measurement unit receives the second light obtained from the first object to be measured, A first spectral characteristic signal relating to the received second light is collected, The light source emits the first light to irradiate a second object to be measured, which is composed only of the second component. The measurement unit receives the third light obtained from the second object to be measured, A second spectral characteristic signal relating to the received third light is collected, A light utilization device in which the signal processing unit extracts the absorbance characteristics of only the first component using the first spectral characteristic signal and the second spectral characteristic signal.

2. Prepare a first object to be measured, which consists of a first component and a second component, and a second object to be measured, which contains only the second component. The first light is shone onto the first object to be measured, From the second light obtained from the first object to be measured, A first spectral characteristic signal relating to the first object to be measured is collected, The first light is shone onto the second object to be measured, From the third light obtained from the second object to be measured, A second spectral characteristic signal relating to the second object to be measured is collected, A light utilization method for extracting the absorbance characteristics of only the first component using the first spectral characteristic signal and the second spectral characteristic signal.

3. Prepare a first object to be measured, which consists of a first component and a second component, and a second object to be measured, which contains only the second component. The first light is shone onto the first object to be measured, From the second light obtained from the first object to be measured, A first spectral characteristic signal relating to the first object to be measured is collected, The first light is shone onto the second object to be measured, From the third light obtained from the second object to be measured, A second spectral characteristic signal relating to the second object to be measured is collected, Using the first spectral characteristic signal and the second spectral characteristic signal, the absorbance characteristic of only the first component is extracted. A service provision method that provides services based on the results of the extraction described above.

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