Sample measurement device

Abstract

A sample measurement device is provided that can realize a simple and compact device configuration and can measure the physical characteristics of a target sample by detecting the polarization state of light. [Solution] Sample measurement device A has a light source 1, a non-polarizing beam splitter 2, a polarization-controlled liquid crystal 3, and a polarization camera 4. Sample measurement device A also has a linear polarizer 6 and an objective lens 7. Furthermore, polarization camera 4 detects horizontally linearly polarized components and vertically linearly polarized components of light that is from light source 1 and originates from light reflected by target sample 5.

Description

[Technical Field]

[0001] The present invention relates to a sample measurement device. [Background technology]

[0002] Conventionally, various methods have been used to non-destructively examine the properties of a material by irradiating a sample to be measured with light and measuring or analyzing information on the reflected light.

[0003] For example, an apparatus has been proposed that measures the physical characteristics of a target sample by detecting the distribution of the direction of propagation of incident light on the target sample (see, for example, Patent Document 1).

[0004] The sample measurement device described in Patent Document 1 performs spatial polarization filtering on both incident light and reflected light to detect tilt, waviness, minute steps, scratches, etc. on the reflecting surface of the sample to be measured.

[0005] In addition, in the sample measurement device described in Patent Document 1, the light irradiated onto the target sample is passed through a polarized beam splitter that selectively extracts polarized components in specific directions (polarized components in the x-axis direction and polarized components in the y-axis direction), and then each polarized component is detected by two polarized cameras. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7525119 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the sample measurement device described in Patent Document 1, in order to detect the polarization component in the x-axis direction and the polarization component in the y-axis direction, as described above, it is necessary to combine a polarizing beam splitter and two cameras, which poses the problem of making the device configuration complex and large.

[0008] Furthermore, since calibration (correction of pixel misalignment, field of view, etc.) is required for each of the two cameras, adjusting the entire system is time-consuming and there is a risk of reduced measurement accuracy.

[0009] Furthermore, the sample measurement device described in Patent Document 1 had room for improvement in terms of detecting with high sensitivity low-intensity light scattered by minute steps on the surface from the light reflected by the target sample.

[0010] Furthermore, the sample measurement device described in Patent Document 1 is a device that acquires only information about the intensity of the polarization component in the x-axis direction and the polarization component in the y-axis direction for reflected light from the target sample, and there was room for improvement in terms of a configuration that could obtain more detailed information about the polarization state in order to investigate the detailed characteristics of a substance.

[0011] The present invention was devised in consideration of the above points, and aims to provide a sample measurement device that can realize a simple and compact device configuration and can measure the physical characteristics of a target sample by detecting the polarization state of light. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the sample measurement device of the present invention comprises a light source; a polarization camera that receives light from the light source reflected from a target sample and detects horizontally and vertically linearly polarized components derived from the reflected light; a specified optical element that can split light at a specific ratio while maintaining its polarization state and that guides a portion of the light emitted from the light source to the target sample and guides a portion of the reflected light to the polarization camera; and a polarization conversion element that is positioned between the target sample and the specified optical element and has multiple sections that can individually control the polarization of the transmitted light, and the polarization conversion element is configured to transmit light from the reflected light whose optical path has shifted from the light incident on the target sample while maintaining the polarization state of the light, and to convert the polarization state of the light to a different polarization state and transmit it depending on the amount of shift in the optical path.

[0013] Here, the light from the light source can be irradiated onto the surface of the target sample using a light source and a specified optical element that can branch the light at a specific ratio and directs a portion of the light emitted from the light source to the target sample.

[0014] Furthermore, the specified optical element can split the light at a specific ratio while maintaining the polarization state, and by guiding a portion of the reflected light reflected from the target sample to the polarization camera, the light from the light source reflected by the target sample can be guided to the polarization camera without converting the polarization state of the light before and after passing through the specified optical element.

[0015] Furthermore, by placing a polarization conversion element between the target sample and a predetermined optical element and having multiple sections that can individually control the polarization of the light that passes through, the polarization of the light can be changed for each section, and the polarization state of a specific polarization can be detected with a polarization camera. As a result, when the light reflected by the target sample contains both high-intensity light that has been specularly reflected and low-intensity light that has been scattered by minute steps on the surface, the polarization can be controlled to detect even weak light with high sensitivity.

[0016] Furthermore, the polarization camera receives light from a light source reflected from a target sample and detects the horizontally and vertically linearly polarized components derived from the reflected light, thereby making it possible to visualize the surface condition of the target sample based on the linearly polarized components in two directions. That is, by acquiring an intensity distribution image of the linearly polarized components in two directions, it is possible to check for minute steps or tilts on the surface of the target sample. Furthermore, since information on the linearly polarized components in two directions can be acquired with a single polarization camera, it becomes easier to miniaturize the entire device. Furthermore, compared to an embodiment using two cameras, the labor required for tasks such as calibration of the polarization camera is reduced, making it easier to adjust the device.

[0017] Furthermore, the polarization conversion element can transmit reflected light whose optical path is deviated from that of the incident light on the target sample while maintaining the polarization state of the light, and can also convert the polarization state of the light to a different polarization state depending on the amount of optical path deviation before transmitting it, making it possible to detect scattered components caused by unevenness, etc. on the surface of the target sample. In other words, when light is scattered by unevenness, etc. on the surface of the target sample to which light is irradiated, a deviation in the optical paths of the incident light and the reflected light occurs. The polarization conversion element converts the polarization state of the reflected light to a different polarization state depending on the amount of optical path deviation, and then compares the image captured by the polarization camera with the image captured by the polarization camera while maintaining the polarization state of the reflected light, making it possible to detect scattered components of light.

[0018] Furthermore, when a polarization camera detects the 45° and 135° linearly polarized components originating from reflected light, it can obtain information on the four linearly polarized components, including the horizontal and vertical linearly polarized components. In other words, by combining and analyzing the intensities of the four linearly polarized components, it is possible to determine the type of polarization of the light reflected from the surface of the target sample, i.e., whether it is linearly polarized, circularly polarized, or elliptically polarized.

[0019] Furthermore, when a phase shifter is detachably installed between the polarization camera and a predetermined optical element and applies a predetermined phase difference to light guided from the predetermined optical element to the polarization camera, the polarization camera can capture images of light reflected from the surface of the target sample and traveling from the predetermined optical element to the polarization camera, both with and without a phase difference. More specifically, the phase shifter applies a phase difference to two orthogonal polarization components of the passing light, thereby changing the state of incident polarization. Based on information about the amount of phase shift applied by the phase shifter and information comparing the changes in the four linearly polarized components with and without a phase shift, the direction of circular rotation (right-handed or left-handed) of the polarization state of the reflected light can be determined. Furthermore, even when the material constituting the target sample has optical anisotropy and the change in the polarization state of the reflected light varies depending on the angle of incidence of the incident light, the change in the polarization state due to the material can be captured by comparing the changes in the four linearly polarized components with and without a phase shift.

[0020] Furthermore, when an electrically controlled variable birefringence polarizing element is installed between the polarization camera and a predetermined optical element and can electrically impart a predetermined phase difference to light guided from the predetermined optical element to the polarization camera, the polarization camera can capture images of light reflected from the surface of the target sample and traveling from the predetermined optical element to the polarization camera, both with and without a phase difference. More specifically, the electrically controlled variable birefringence polarizing element can impart a phase difference to two orthogonal polarization components of the passing light, thereby changing the state of incident polarization. Based on information about the amount of phase difference imparted by the electrically controlled variable birefringence polarizing element and information comparing the changes in the four linearly polarized components with and without phase difference, it is possible to determine the polarization state of the reflected light, including the direction of rotation of circularly polarized light. Furthermore, even when the material constituting the target sample has optical anisotropy and the change in the polarization state of the reflected light varies depending on the angle of incidence of the incident light, comparing the changes in the four linearly polarized components with and without phase difference can capture changes in the polarization state due to the material.

[0021] Furthermore, if the Stokes parameters of the target sample can be obtained based on the information on the polarization components detected by the polarization camera, the polarization state of the light reflected from the surface of the target sample can be identified as information on the physical quantity that represents the physical properties of polarization.

[0022] Furthermore, if the specified optical element is a non-polarizing beam splitter, it is possible to treat the light irradiated from the light source onto the target sample and the reflected light returning from the target sample on the same optical axis, which simplifies the optical system, facilitating adjustment of the device and reducing manufacturing costs. [Effects of the Invention]

[0023] The sample measurement device according to the present invention can realize a simple and compact device configuration, and can measure the physical characteristics of a target sample by detecting the polarization state of light. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram showing the overall configuration of a first embodiment of the present invention. [Figure 2] FIG. 10 is a schematic diagram showing the overall configuration of a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic diagram showing the overall configuration of a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, modes for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the drawings. The following description is an example of a sample measurement device to which the present invention is applied, and the present invention is not limited to this example, and the design can be modified as appropriate.

[0026] [First embodiment of the present invention] As shown in FIG. 1, the sample measurement device A has a light source 1, a non-polarizing beam splitter 2, a polarization control liquid crystal 3, and a polarization camera 4.

[0027] This sample measurement device A is a device that irradiates light from a light source 1 onto a target sample 5 (see Figure 1), captures an image of the light reflected on the surface of the target sample 5 with a polarization camera 4, and measures the polarization state of the reflected light.

[0028] The sample measurement device A also has a linear polarizer 6 and an objective lens 7 (see FIG. 1).

[0029] Here, the light source 1 is a member for emitting light to irradiate the target sample 5, and for example, an LED light source can be used.

[0030] The non-polarizing beam splitter 2 is an optical element that directs a portion of the light emitted from the light source 1 to the target sample 5. The non-polarizing beam splitter 2 is also a component that directs a portion of the light reflected on the surface of the target sample to the polarization camera 4.

[0031] The non-polarizing beam splitter 2 referred to here is a member that corresponds to the predetermined optical element in the claims of the present application.

[0032] The non-polarizing beam splitter 2 is an optical element that splits the incident light at a constant rate while maintaining the polarization state of the light. That is, for example, part of the light incident on the non-polarizing beam splitter 2 is reflected toward the target sample 5, and the remaining part passes through the non-polarizing beam splitter 2 and is split at a constant rate.

[0033] The polarization control liquid crystal 3 is a liquid crystal element made up of a plurality of sections, and controls polarization for each section. The plurality of sections are, for example, planar and arranged in a grid pattern.

[0034] The polarization-controlled liquid crystal 3 is a component that can transmit light whose optical path has shifted between the incident light and the reflected light on the target sample by converting the polarization state of the reflected light into a different polarization state for each section depending on the amount of the shift in the optical path. Details of this section will be described later.

[0035] The polarization control liquid crystal 3 here is a member that corresponds to the polarization conversion element in the claims of the present application.

[0036] The linear polarizer 6 is a polarizer that converts the light from the light source 1 into linearly polarized light that vibrates in only one direction (for example, linearly polarized light that vibrates only in the y-axis direction).

[0037] The objective lens 7 is a lens element that collects light that passes through the polarization control liquid crystal 3 and heads toward the target sample 5. The objective lens 7 is also a lens element that collects light reflected by the target sample 5 and directs it toward the polarization camera 4.

[0038] In addition, the polarization camera 4 is a camera that detects the horizontal linear polarization component (linear polarization component that vibrates only in the x direction) and the vertical linear polarization component (linear polarization component that vibrates only in the y direction) of the light from the light source 1 that originates from the light reflected by the target sample 5.

[0039] This polarization camera 4 can acquire intensity distribution images of linearly polarized light components in two directions, the horizontal and vertical directions.

[0040] In addition, in the sample measurement device A, the non-polarizing beam splitter 2 is arranged between the light source 1 and the polarization control type liquid crystal 3, and between the polarization control type liquid crystal 3 and the polarization camera 4 in the light propagation path.

[0041] Due to the positioning of the non-polarizing beam splitter 2, the sample measurement device A can handle the light irradiating the target sample and the light reflected from the surface of the target sample on the same optical axis.

[0042] In the sample measurement device A, the polarization control liquid crystal 3 is disposed between the non-polarizing beam splitter 2 and the objective lens 7 .

[0043] In the sample measurement device A, the light source 1, the non-polarizing beam splitter 2, and the polarization control liquid crystal 3 are all arranged on one side of the target sample 5 (the reflecting surface side).

[0044] Here, it is not necessary to use a non-polarizing beam splitter 4 in the sample measurement device A, and any optical element that can split light at a constant rate while maintaining the polarization state can be used, for example, a half mirror. However, it is preferable to use a non-polarizing beam splitter 4 in the sample measurement device A because it allows the light irradiated from the light source 1 and the light reflected from the target sample 5 to be handled on the same optical axis, simplifying the optical system and facilitating adjustment of the device, and because the polarization dependency of the transmittance and reflectance is small for each type of polarization, making it easy to correct for polarization characteristics.

[0045] Next, we will explain the propagation path of light in the sample measurement device A. First, light emitted from the light source 1 passes through the linear polarizer 6, and is converted by the linear polarizer 6 into linearly polarized light that vibrates only in the y-axis direction.

[0046] Furthermore, the light that has passed through the linear polarizer 6 reaches the non-polarizing beam splitter 2, where a portion of the light is reflected toward the polarization control liquid crystal 3, and this light passes through the polarization control liquid crystal 3 in a linearly polarized state. At this time, the section of the polarization control liquid crystal 3 through which the light passes is controlled by a setting that maintains the polarization state.

[0047] Furthermore, the light that has passed through the polarization-controlled liquid crystal 3 is collected by the objective lens 7 and irradiated onto the surface of the target sample. The irradiated light is reflected from the surface of the target sample, and the reflected light is collected by the objective lens 7 and passes through the polarization-controlled liquid crystal 3 again.

[0048] Furthermore, the polarization-controlled liquid crystal 3 can transmit light reflected from the target sample by changing the polarization for each section. In the polarization-controlled liquid crystal 3, which of the multiple sections the light passes through depends on the way the light is reflected on the surface of the target sample (whether it is scattered or not, etc.).

[0049] The reflected light includes specularly reflected light whose optical path is not deviated from that of the incident light, and reflected light whose optical path is deviated due to scattering caused by the unevenness of the surface of the target sample. Normally, the majority of reflected light is specularly reflected light, and the proportion of scattered light is small.

[0050] Therefore, by controlling the polarization in the section through which the specularly reflected light passes, the polarization-controlled liquid crystal 3 reduces the amount of specularly reflected light with high intensity when the reflected light is captured by the polarization camera 4, enabling highly sensitive detection of scattered reflected light with low intensity. More specifically, by converting specularly reflected light into a specific polarized light, the amount of specific polarized light components detected by the polarization camera is reduced, resulting in a phenomenon known as dark field mode. As a result, it is possible to visualize light with low intensity (a small component).

[0051] In addition, the polarization-controlled liquid crystal 3 can adjust the polarization state of the reflected light that passes through the target sample by either allowing the reflected light to pass through each section while maintaining its polarization state, or converting the polarization state of the reflected light into a different polarization state and passing it through the section through which the reflected light passes, depending on the amount of deviation in the optical path.

[0052] Here, converting the polarization state of reflected light into another polarization state depending on the amount of optical path deviation in the section through which the reflected light passes due to the optical path deviation means, for example, the following conversion.

[0053] In section a, through which the reflected light with a certain amount of optical path deviation passes, the linearly polarized light vibrating only in the y-axis direction is rotated by 90 degrees, converted into linearly polarized light vibrating only in the x-axis direction, and then passes through section a.

[0054] In addition, in section b, through which reflected light with a different amount of optical path deviation passes, linearly polarized light vibrating only in the y-axis direction is rotated by 45 degrees, converted into linearly polarized light with vibration components in both the x-axis and y-axis directions, and then passed through section b.

[0055] Furthermore, in section c, through which specularly reflected light without any deviation in the optical path passes, linearly polarized light vibrating only in the y-axis direction is passed without being rotated as linearly polarized light vibrating only in the y-axis direction.

[0056] In this way, in the polarization control liquid crystal 3, the reflected light passes through different sections depending on the amount of deviation of the optical path, and can be converted into a different polarization state for each section.

[0057] The reflected light that passes through the polarization control liquid crystal 3 then enters the non-polarizing beam splitter 2, where it is split at a fixed rate while maintaining its polarization state, passes through the non-polarizing beam splitter 2, and enters the polarization camera 4.

[0058] Furthermore, depending on whether or not the polarization state of light is converted according to the amount of deviation in the optical path by the polarization-controlled liquid crystal 3 described above, the polarization camera 4 can obtain detection results that are a mixture of two types of detection: detection of reflected light whose polarization state is maintained in each section of the polarization-controlled liquid crystal 3, and detection of reflected light that is converted into a different polarization state depending on the section.

[0059] By checking the mixed detection results obtained by the polarization camera 4, it becomes possible to identify scattering caused by surface irregularities of the target sample as differences in polarization state. In other words, the sample measurement device A can separate the scattering components caused by surface irregularities of the target sample.

[0060] In this way, in the sample measurement device A, by detecting horizontal and vertical linear polarization components using the polarization camera 4, it is possible to accurately detect minute irregularities, steps, scratches, tilt of the reflecting surface, waviness, etc. on the surface of the target sample.

[0061] Furthermore, the sample measurement device A can be constructed by combining the non-polarizing beam splitter 2 and one polarization camera 4, so the device configuration is relatively simple and the entire device can be made compact.

[0062] [Second embodiment of the present invention] Next, a second embodiment of the present invention will be described. A sample measurement device B according to the second embodiment of the present invention is shown in Figure 2. Note that the same components as those in the first embodiment of the present invention described above are given the same reference numerals and their description will be omitted.

[0063] As shown in FIG. 2, the sample measurement device B has a polarization camera 40.

[0064] This polarization camera 40 is a camera that detects horizontally linearly polarized components, vertically linearly polarized components, 45° linearly polarized components, and 135° linearly polarized components of light that is emitted from the light source 1 and originates from light reflected by the target sample 5.

[0065] This polarization camera 40 can acquire intensity distribution images of linearly polarized light components in four directions: horizontal, vertical, 45°, and 135°.

[0066] As a result, the sample measurement device B can identify the type of polarization, i.e., linear polarization, circular polarization, or elliptically polarization, based on the intensity of the linearly polarized components in four directions, regarding the polarization state of the light reflected from the target sample.

[0067] Sample measurement device B can obtain information on the type of polarization that could not be confirmed from information on the two-directional linear polarization components, horizontal and vertical, alone, and can grasp the polarization state of the reflected light in more detail.

[0068] [Third embodiment of the present invention] Next, a third embodiment of the present invention will be described. A sample measurement device C according to the third embodiment of the present invention is shown in Figure 3. Note that the same components as those in the first and second embodiments of the present invention described above are given the same reference numerals and their description will be omitted.

[0069] As shown in Figure 3, the sample measurement device C has a λ / 4 plate 8. This λ / 4 plate 8 is an element that imparts a phase difference of λ / 4 (90°) to one of the two orthogonal polarization components that make up the polarization of light that has passed through the non-polarizing beam splitter 2, thereby changing the state of incident polarization. Note that the λ / 4 plate 8 referred to here is a component that corresponds to the phase shifter in the claims of this application.

[0070] For example, if the light incident on the λ / 4 plate 8 from the non-polarizing beam splitter 2 is linearly polarized at 45°, the light that passes through the λ / 4 plate 8 is given a phase difference of λ / 4 (90°) and is converted into circularly polarized light.

[0071] The sample measurement device C also has a polarization camera 40. In the sample measurement device C, a λ / 4 plate 8 is also installed so as to be detachable.

[0072] Depending on whether or not the λ / 4 plate 8 is attached or detached, the polarization state of the light that does not pass through the λ / 4 plate 8 (when the λ / 4 plate 8 is removed) and the light that passes through the λ / 4 plate 8 (when the λ / 4 plate 8 is installed) can be obtained by the polarization camera 40.

[0073] In other words, in the sample measurement device C, by attaching or detaching the λ / 4 plate 8 and capturing the reflected light from the target sample with the polarization camera 40, eight types of intensity distribution images can be obtained, which are patterns of linearly polarized components in four directions (horizontal, vertical, 45° and 135° directions) and with or without phase difference.

[0074] In other words, by making it possible to obtain information on the changes in amplitude and phase of the polarization components of the polarization state of the light reflected from the target sample, it is possible to confirm not only the type of polarization but also the direction of rotation of the circularly polarized light (right-handed or left-handed) regarding the polarization state of the reflected light.

[0075] Here, by obtaining information on the intensity distribution of linearly polarized components in four directions (horizontal, vertical, 45° and 135°), the type of polarization, and the direction of rotation of circularly polarized light, all the information necessary to identify the state of the electromagnetic wave of light is obtained.

[0076] This makes it possible for the sample measurement device C to separate the polarization characteristics of the material of the target sample 5 made of a material that has optical anisotropy (exhibits birefringence).

[0077] That is, when the material constituting the target sample 5 is made of a material having optical anisotropy, the change in the polarization state of the reflected light of light incident on the surface of the target sample 5 changes depending on the angle of incidence. The polarization state of reflected light from incident light at a certain angle of incidence remains unchanged, but the polarization state of reflected light from incident light at a different angle of incidence is reflected in a polarization state different from the polarization state of the incident light.

[0078] The sample measurement device C can capture changes in the polarization state caused by the optical anisotropy of the material that makes up the target sample 5 by comparing the changes in the linearly polarized components in four directions with and without the λ / 4 plate 8.

[0079] Furthermore, by using the sample measurement device C to obtain information on the changes in the linearly polarized light components in four directions with and without the λ / 4 plate 8, it becomes possible to calculate the Stokes parameters, which are physical quantities that represent the physical properties of polarized light.

[0080] The Stokes parameters S0, S1, S2, and S3 are generally defined as follows: S0 is the total light intensity; S1 is the difference in light intensity between the 0° linearly polarized component and the 90° linearly polarized component; S2 is the difference in light intensity between the 45° linearly polarized component and the 135° linearly polarized component; and S3 is the difference in light intensity between the right-handed circularly polarized component and the left-handed circularly polarized component.

[0081] In this way, with the sample measurement device C, it is possible to express the polarization state of the light reflected from the target sample as Stokes parameters.

[0082] Here, the λ / 4 plate 8 does not necessarily need to be detachably installed in the sample measurement device C, and an electrically controlled variable birefringence polarizing element can be used instead of the λ / 4 plate 8. For example, an electrically controlled birefringence liquid crystal, which is an example of an electrically controlled variable birefringence polarizing element, uses the birefringence of the liquid crystal to change the phase difference by applying a voltage to the liquid crystal molecules, and can impart a phase difference to the light passing through.

[0083] Furthermore, the sample measurement device C does not necessarily require that the λ / 4 plate 8 be detachably installed; wave plates that impart different amounts of phase shift to light can be used. For example, a λ / 2 plate can be used. Furthermore, as long as it is possible to measure multiple polarization states with or without a phase shift, and the amount of phase shift to be imparted is clear, wave plates other than λ / 4 plates and λ / 2 plates can also be used.

[0084] In this way, in the sample measurement device C, which is the third embodiment of the present invention, information is obtained regarding the polarization state of reflected light from the target sample 5, such as the intensity distribution of linearly polarized components in four directions, the type of polarization, and the direction of rotation of circularly polarized light, making it possible to confirm the detailed polarization state of the reflected light.

[0085] The sample measuring devices according to the first to third embodiments of the present invention are useful as a technique for detecting, for example, minute steps and thin film irregularities on the surface of a semiconductor wafer, glass substrate, or the like at high speed.

[0086] It is also possible to visualize and quantify extremely small scratches and defects on the surfaces of smartphone terminal components, optical devices, etc.

[0087] It also makes it possible to detect unevenness on the order of nano to submicron, which was difficult to detect using conventional simple illumination and observation methods.

[0088] As described above, the sample measurement device of the present invention can realize a simple and compact device configuration, and is capable of measuring the physical characteristics of a target sample by detecting the polarization state of light.

[0089] The invention made by the inventor has been specifically described above based on an embodiment, but it goes without saying that the present invention is not limited to the above embodiment and can be modified in various ways without departing from the gist of the invention. [Explanation of symbols]

[0090] A Sample measurement device 1 light source 2. Non-polarizing beam splitter 3. Polarization-controlled LCD 4 Polarization camera 5. Target samples 6 Linear polarizer 7 Objective Lens B. Sample measurement device 40 Polarization Camera C. Sample measurement device 8 λ / 4 plate

Claims

1. a predetermined optical element capable of splitting light at a specific ratio while maintaining the polarization state, and guiding a portion of the light emitted from the light source to the target sample and guiding a portion of the reflected light from the target sample to a light receiving unit; a polarization conversion element disposed between the target sample and the predetermined optical element, the polarization conversion element having a plurality of sections capable of individually controlling the polarization of light passing through the polarization conversion element; The polarization conversion element is capable of transmitting light from the reflected light whose optical path has shifted from that of the incident light on the target sample while maintaining the polarization state of the light, or converting the polarization state of the light into another polarization state and transmitting the light according to the amount of shift in the optical path. Sample measurement device.

2. The predetermined optical element is a non-polarizing beam splitter. The sample measurement device according to claim 1 .

3. The device is arranged between the target sample and a predetermined optical element that guides a portion of the light emitted from the light source to the target sample and guides a portion of the reflected light reflected from the target sample to a light receiving section, and has a plurality of sections that can individually control the polarization of the light that passes through it, and also has a polarization conversion element that can transmit, with the reflected light having an optical path that is shifted from the incident light on the target sample, while maintaining the polarization state of the light, or can convert the polarization state of the light to another polarization state and transmit it according to the amount of the optical path shift. Sample measurement device.

Images