Spectrometer

Abstract

The present invention provides a spectrometer, comprising: a transmitting system, comprising: a control device, used for generating a plurality of wavelength encoding data corresponding to a plurality of wavebands to be measured; a light source, used for emitting light source light, the light source light comprising light beams of the plurality of wavebands to be measured, and the light beams of the light source light of different wavebands to be measured are separated from each other in space; and a modulation device, comprising a plurality of modulation sub-regions, the plurality of modulation sub-regions modulating the light source light of the corresponding waveband to be measured according to the corresponding wavelength encoding data and obtaining a first detection light having the corresponding wavelength encoding data information, the first detection light being transmitted along a first direction and irradiated to the surface of a target to be measured; and a receiving system, used for determining the light beams of each waveband to be measured included in the received first target light, and the absorption characteristics and / or reflection characteristics of the target to be measured for the light beams of different wavebands to be measured, according to the relationship between the light intensity of the first target light and time and the plurality of wavelength encoding data.

Description

Technical Field

[0001] The present invention relates to the technical field of spectrum analysis and detection, and in particular to a spectrometer. Background Art

[0002] This section is intended to provide a background or context to the detailed description of the invention as recited in the claims. No admission is made that the description herein is prior art by inclusion in this section.

[0003] The spectrometer can separate composite light into narrow spectra, and determine the composition and other information of the measured object by measuring the spectral characteristics of the target light (such as the self-luminous or reflected light of the object). According to the principle of spectrum decomposition adopted by the spectrometer, it can be divided into two categories: classical spectrometer based on spatial dispersion and modulation spectrometer based on modulation principle. Classical spectrometers include, for example, prism spectrometers, diffraction grating spectrometers, interference spectrometers, etc.; modulation spectrometers include, for example, Fourier transform spectrometers, Hadamard transform spectrometers, fence modulation spectrometers, etc.

[0004] At present, spectrometers are widely used in biochemistry, food hygiene, environmental testing, space exploration and other fields. In recent years, with the improvement of living standards, people pay more and more attention to food safety. Spectrometers can detect pesticide residues on the surface of fruits and vegetables. From the perspective of portability, the size of the spectrometer needs to be as small as possible. However, it is often difficult to take into account the detection accuracy while reducing the size. Therefore, a portable spectrometer with small size and high detection accuracy is urgently needed. Summary of the invention

[0005] The present invention provides a spectrometer, comprising: a transmitting system, comprising:

[0006] The transmitting system comprises: a control device for generating a plurality of wavelength encoding data corresponding to a plurality of wavebands to be measured one by one; a light source for emitting light source light, the light source light comprising light beams of a plurality of wavebands to be measured, and the light source light beams of different wavebands to be measured are spatially separated from each other; and a modulation device, comprising a micromirror array including a plurality of microreflectors, having a plurality of modulation sub-regions, each modulation sub-region corresponding to a waveband to be measured and a wavelength encoding data, the plurality of modulation sub-regions modulating the light source light of the corresponding waveband to be measured according to the corresponding wavelength encoding data and obtaining a first detection light having the corresponding wavelength encoding data information, thereby realizing the encoding of the light source light by the modulation device, the first detection light is transmitted along a first direction and irradiated to the surface of the target to be measured; and a receiving system for determining the light beams of each waveband to be measured included in the received first target light, and the absorption characteristics and / or reflection characteristics of the target to be measured for the light beams of different wavebands to be measured, according to the relationship between the light intensity of the first target light emitted by the target to be measured, including the reflected first detection light, and the time variation, and the plurality of wavelength encoding data.

[0007] In one embodiment, the control device is also used to generate a plurality of verification data corresponding one by one to the plurality of wavelength bands to be measured; the plurality of modulation sub-areas also modulate the light source light of the corresponding wavelength band to be measured according to the corresponding wavelength coding data and obtain a second detection light having the corresponding verification data information, thereby realizing the encoding of the light source light by the modulation device, and the second detection light is transmitted along the second direction and irradiated to the surface of the target to be measured; and the receiving system also determines the light beams of each wavelength band to be measured included in the received second target light, and the absorption characteristics and / or reflection characteristics of the target to be measured for the light beams of different wavelength bands to be measured, according to the relationship between the light intensity of the second target light emitted by the target to be measured including the reflected second detection light and time, and the plurality of verification data.

[0008] In one implementation, the wavelength encoding data is binary data, and the check data is obtained by inverting each bit of the corresponding wavelength encoding data.

[0009] In one embodiment, each wavelength-encoded data has a plurality of data bits, and the modulation device is provided with at least one micro-reflector in each modulation sub-region, and at least part of the modulation units in each modulation sub-region sequentially control the ratio of the first detection light and the second detection light corresponding to the wavelength band to be measured according to the numerical value of each data bit of the corresponding wavelength-encoded data. If each modulation sub-region uses a different number of micro-reflectors, the wavelength band to be measured is further light-intensity encoded, which is conducive to improving the efficiency and accuracy of the receiving system in identifying the wavelength band of the light beam.

[0010] In one embodiment, the modulation unit is a micro-mirror having multiple stable states, and the proportions of the first detection light corresponding to the measured band emitted by the micro-mirror are different when the micro-mirror is in different stable states, and the proportions of the second detection light corresponding to the measured band emitted by the micro-mirror are different when the micro-mirror is in different stable states, and the micro-mirrors in each modulation sub-area are in the corresponding steady state in sequence according to the value of each data bit in the corresponding wavelength-encoded data.

[0011] In one embodiment, the micro-reflector has a first stable state and a second stable state. When the micro-reflector is in the first stable state, the proportion of the first detection light emitted by the micro-reflector is 100%, and the proportion of the second detection light emitted by the micro-reflector is 0%; when the micro-reflector is in the second stable state, the proportion of the first detection light emitted by the micro-reflector is 0%, and the proportion of the second detection light emitted by the micro-reflector is 100%.

[0012] In one embodiment, the receiving system includes a first receiving subsystem and a second receiving subsystem, the first receiving subsystem is used to receive the first target light and decode the first target light according to the wavelength encoding data, and the second receiving subsystem is used to receive the second target light and decode the second target light according to the verification data.

[0013] In one embodiment, the light source includes N light beams of a band to be measured, the control device generates a timing coded data for each detection of the target to be measured, the modulation device modulates the light source light according to the timing coded data, and the time period is a modulation period, the modulation period includes N modulation time periods, and the modulation device is used to modulate the light beam corresponding to the band to be measured using the data in different data bits in the wavelength coded data in different modulation time periods.

[0014] In one embodiment, each modulation cycle includes a plurality of modulation time periods corresponding to a plurality of wavebands to be measured, and in each modulation cycle, the modulation device emits modulated sub-beams of different wavebands to be measured as first detection light in different modulation time periods. Therefore, the receiving system can only detect the influence of the detection light beam belonging to one waveband to be measured on the emitted light intensity of the target to be measured at one time, which is conducive to improving the efficiency and accuracy of the receiving system in identifying the waveband of the light beam.

[0015] In one embodiment, the light source includes a light-emitting unit and a dispersion component, wherein the light-emitting unit is used to generate broadband light, the broadband light including a plurality of light beams of wavelength bands to be measured that overlap with each other in space, and after the broadband light passes through the dispersion component, light source light is obtained in which the light beams of different wavelength bands to be measured are spatially separated from each other.

[0016] In one embodiment, the dispersion component includes a first diffraction element and a second diffraction element. The broad-spectrum light passes through the first diffraction element and the second diffraction element in sequence to obtain first-order diffraction light and second-order diffraction light respectively. The first-order diffraction light includes a plurality of light beams of different bands spaced apart from each other in space along a first direction. A light beam of each band in the first-order diffraction light is converted into a light beam of a portion of the bands to be measured in a plurality of bands to be measured spaced apart from each other along a second direction in the second-order diffraction light. The first direction is different from the second direction. The second-order diffraction light is used as a light source.

[0017] In one embodiment, the first diffraction element and the second diffraction element are both transmissive gratings.

[0018] In one embodiment, the first diffraction element is a reflective grating, and the second diffraction element is a transmissive grating.

[0019] In one embodiment, the transmitting system further includes a light homogenizing device, and the first detection light or the second detection light emitted by the modulation device is used to irradiate the target to be measured after being homogenized by the light homogenizing device. The uniformly mixed detection light is irradiated on the target to be measured, which can improve the uniformity of the detection light after being reflected by the target to be measured, and avoid the randomness and uncertainty of the detection intensity distribution caused by uneven spatial distribution.

[0020] In one embodiment, the light source includes a light-emitting body array, and each light-emitting body in the light-emitting body array is used to emit a light beam in a wavelength band to be measured in the light source light.

[0021] In one embodiment, the array of light emitters includes an array of light emitting diodes or an array of laser diodes.

[0022] In one embodiment, the light source includes a wavelength conversion material array and a light emitting diode or a laser diode, the wavelength conversion material array includes a plurality of wavelength conversion units made of different materials arranged in an array, and each wavelength conversion unit is used to generate a light beam in a wavelength band to be measured in the light of the light source under the excitation of light emitted by the light emitting diode or the laser diode.

[0023] In one embodiment, the light source is infrared light.

[0024] The present invention provides a spectrometer that uses a modulation device (MEMS) to perform identifiable encoding on light source light and obtain detection light, which is irradiated onto a target to be measured, and decodes the target light emitted by the target to be measured through a receiving system, thereby accurately determining the absorption characteristics and / or reflection characteristics of light beams of different wavelengths and determining the composition of the target to be measured. The spectrometer has the advantages of high precision and accuracy in the wavelength range of the detection light beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments / methods of the present invention, the drawings required for use in the description of the embodiments / methods will be briefly introduced below. Obviously, the drawings described below are some embodiments / methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a schematic structural diagram of a spectrometer provided in the first embodiment of the present invention.

[0027] Figure 2 for Figure 1 Schematic diagram of the intermediate image shown.

[0028] Figure 3 This is a timing diagram of a modulation signal.

[0029] Figure 4 This is a timing diagram of another modulation signal.

[0030] Figure 5 This is a schematic structural diagram of a spectrometer provided in accordance with a second embodiment of the present invention.

[0031] Main component symbols

[0032] Spectrometer 100、200 Launch system 110、210 Light emitting unit 111、211 Dispersion Components 112、212 First diffractive element 1121、2121 The second diffractive element 1122、2122 Imaging optical system 113、213 Intermediate Image A Modulation Signal S11, S12,…,Sij,…,Smn cycle T Modulation period Δt Light splitting and combining device 114 Modulation device 115 Controls 116 light source 119 Reflective element 218 Receiving system 130、230 detector 131 Data Processor 132 Target to be tested P

[0033] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0034] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. The embodiments described are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] The present invention provides a spectrometer, which performs identifiable encoding on detection light according to multiple wavelength encoding data, irradiates the detection light onto a target to be measured, and detects the light intensity of the target light emitted by the target to be measured through a receiving system, and determines the light beams of each wavelength band to be measured included in the received target light according to the multiple wavelength encoding data, that is, decodes the target light through the receiving system, thereby accurately determining the absorption characteristics and / or reflection characteristics of light beams of different wavelengths and determining the composition of the target to be measured. The spectrometer has the advantages of small size and high precision and accuracy in the wavelength range of the detection light beam.

[0038] See also Figure 1, the spectrometer 100 provided in the first embodiment of the present invention is a portable spectrometer, but is not limited to portable in other embodiments. The spectrometer 100 includes a transmitting system 110 and a receiving system 130. The transmitting system 110 includes a light source 119, a modulator 115 and a control device 116. The control device 116 is used to generate a plurality of wavelength encoding data corresponding to a plurality of wavelength bands to be measured, the light source 119 is used to emit a light source light, the light source light includes a plurality of light beams of wavelength bands to be measured, and the light source light beams of different wavelength bands to be measured are separated from each other in space; the modulator 115 is used to modulate the light source light according to the plurality of wavelength encoding data and obtain modulated light. Specifically, the modulator 115 has a plurality of modulation sub-areas, each modulation sub-area corresponds to a wavelength band to be measured and a wavelength encoding data, each modulation sub-area modulates the light source light of the corresponding wavelength band to be measured according to the corresponding wavelength encoding data and obtains a modulated sub-beam with the corresponding wavelength encoding data information, and the plurality of modulated sub-beams emitted by the modulator 115 are used as the first detection light irradiated to the target P to be measured. The receiving system 130 is used to detect the relationship between the light intensity of the first target light emitted by the target P to be measured, including the reflected first detection light, and time, as well as multiple wavelength encoding data, to determine the light beams of each waveband to be measured included in the received first target light, and the absorption characteristics and / or reflection characteristics of the target to be measured for the light beams of different wavebands to be measured.

[0039] Specifically, the multiple wavebands to be measured to which the light source light emitted by the spectrometer 100 belongs do not overlap and are pre-set parameters of the spectrometer 100, or the multiple wavebands to be measured can be set by the user through the external input device (mouse, keyboard, touch display panel, etc.) of the spectrometer 100. For the sake of calculation simplicity, the bandwidth of the light source light in this embodiment is taken as 0.1 μm. Usually, the accuracy of the detection wavelength range of the spectrometer can reach 1 nm (that is, the spectrometer can distinguish two types of light with a wavelength difference of 1 nm). In the present invention, the bandwidth of the light source light can be evenly divided into 100 wavebands to be measured, and the bandwidth of each waveband to be measured is 1 nm. The control device 116 generates wavelength encoding data corresponding to multiple wavebands to be measured, that is, each wavelength encoding data corresponds to a waveband to be measured, and different wavebands to be measured have different corresponding wavelength encoding data. The control device 116 can randomly generate the wavelength encoding data or obtain the wavelength encoding data according to a predetermined algorithm or formula.

[0040] like Figure 1As shown, the light source 119 includes a light emitting unit 111 and a dispersion component 112, wherein the light emitting unit 111 is used to generate broadband light, and the broadband light includes a plurality of light beams of wavelength bands to be measured that overlap each other in space. In one embodiment, the light beams of various wavelength bands in the broadband light are uniformly distributed in space, that is, at a spatial point on the transmission optical path of the broadband light, there are lights of multiple wavelength bands to be measured. The broadband light is preferably infrared light, and the spectrometer 100 uses the absorption characteristics of the material to infrared radiation of different wavelengths to perform molecular structure and chemical composition analysis. The material is composed of continuously vibrating atoms, and the vibration frequency of these atoms is equivalent to the vibration frequency of infrared light. When infrared light is irradiated on organic matter, the molecules absorb infrared light and vibration energy level transitions occur. Different chemical bonds or functional groups have different absorption frequencies. Each organic molecule only absorbs the infrared spectrum consistent with its molecular vibration and rotation frequency. The resulting absorption spectrum is usually called an infrared absorption spectrum. By analyzing the infrared spectrum, the material can be qualitatively analyzed. The content of each substance will also be reflected in the infrared absorption spectrum, and quantitative analysis can be performed based on the peak position and absorption intensity. In this embodiment, the broadband light has a bandwidth of 0.1 μm and a wavelength range of 1.9 μm-2.0 μm. The light emitting unit 111 may be a light emitting diode light source or a laser diode light source, that is, the light emitting unit 111 may include a light emitting diode, a light emitting diode array, a laser diode or a laser diode array.

[0041] The dispersion component 112 is used to disperse and split the incident broadband light. Furthermore, the beams of multiple wavebands to be measured in the broadband light overlap in space. After the broadband light passes through the dispersion component 112, the light source light in which the beams of different wavebands to be measured are separated from each other in space is obtained. In this embodiment, there are 100 wavebands to be measured, and then a beam of broadband light is divided into 100 beams in the light source light by the dispersion component 112. Each beam in the light source light belongs to a waveband to be measured, that is, the wavelength range of each beam in the light source light is within the range of a waveband to be measured, and different beams in the light source light belong to different wavebands to be measured, that is, the dispersion component 112 is used to divide the broadband light into a plurality of beams corresponding to the wavebands to be measured according to the plurality of wavebands to be measured.

[0042] Specifically, in this embodiment, the dispersion component 112 includes a first diffraction element 1121 and a second diffraction element 1122. The first diffraction element 1121 and the second diffraction element 1122 are both transmission gratings, that is, the light is diffracted and transmitted in the first diffraction element 1121 and the second diffraction element 1122. In this embodiment, the first diffraction element 1121 includes a transparent substrate and a series of grooves formed on the substrate, and the wide spectrum light forms a striped diffraction pattern after passing through the first diffraction element 1121. In one embodiment, the first diffraction element 1121 includes a transparent substrate and a series of strip grooves formed on the substrate. In another embodiment, the first diffraction element 1121 includes a metal substrate and a series of slits formed on the metal substrate. The structure of the second diffraction element 1122 can be the same as or different from that of the first diffraction element 1121. The first diffraction element 1121 has m grooves, and the second diffraction element 1122 has n grooves. In this implementation, for ease of calculation, the plurality of wavebands to be measured are 100 wavebands, and m=n=10.

[0043] The first diffraction element 1121 and the second diffraction element 1122 have different dispersion splitting directions. In this embodiment, the first diffraction element 1121 and the second diffraction element 1122 have their splitting directions perpendicular to each other, that is, the extension directions of the scribed lines of the first diffraction element 1121 and the second diffraction element 1122 are perpendicular to each other. Figure 1 As shown, the scribed lines of the first diffraction element 1121 are along Figure 1 The second diffraction element 1122 extends in the vertical direction, and the lines of the second diffraction element 1122 extend perpendicular to Figure 1 It can be understood that the extension direction of the scribed lines of the first diffraction element 1121 and the second diffraction element 1122 can also be Figure 1 The directions shown in are different.

[0044] The broadband light passes through the first diffraction element 1121 and the second diffraction element 1122 in sequence to obtain first-order diffraction light and second-order diffraction light respectively. The first-order diffraction light includes the first direction ( Figure 1 The first diffraction element 1211 is a first diffraction element that converts a beam of incident broad-spectrum light into 10 beams of first-order diffraction light with non-overlapping bandwidths. The bandwidths of the 10 beams of first-order diffraction light are added together to form a bandwidth of the broad-spectrum light. A beam of each wavelength band in the first-order diffraction light is converted into a beam of incident broad-spectrum light along the second direction (perpendicular to the vertical direction in the first diffraction light). Figure 1The first diffraction element 1122 is used to disperse and split light beams of some of the wavelength bands to be measured in the plurality of wavelength bands to be measured that are spaced from each other (in the paper direction in the figure), that is, each beam of the first-order diffraction light is dispersed and split by the second diffraction element 1122, and each beam of the first-order diffraction light is divided into multiple beams of narrower wavelength bands. For example, after the first beam of the first-order diffraction light (with a central wavelength of λ1) passes through the second diffraction element 1122, n beams of light with non-overlapping wavelength ranges are obtained, and the central wavelengths are λ11...λ1n, respectively. After all the first diffraction light beams pass through the second diffraction element 1122, 100 beams of light beams with central wavelengths of λ11...λ1n, λ21...λ2n, λm1...λmn are obtained. The bandwidth of each beam of light is recorded as λij, ΣΔλij=Δλi, where j=1,2,...n, ΣΔλij=Δλ, where i=1,2,...m, j=1,2,...n, and in this embodiment, m=n=10. That is, after a plurality of light beams spaced apart along the first direction in the first diffraction light pass through the second diffraction element 1122, a light beam array of the second diffraction light arranged in a matrix along the first direction and the second direction is obtained. The wavelength ranges of different light beams in the light beam array do not overlap, and each light beam belongs to a wave band to be measured. Different light beams in the light beam array belong to different wave bands to be measured. A two-dimensionally distributed intermediate image A is formed on the transmission path of the second diffraction light. The intermediate image A is as shown in FIG. Figure 2 As shown, the intermediate image A is a two-dimensional matrix including m×n pixels, the wavelength ranges of the light beams irradiating different pixels do not overlap with each other, and the central wavelength of the secondary diffraction light irradiating each pixel is λij.

[0045] In a modified embodiment, the light source 119 includes a light-emitting body array for emitting light from the light source, each light-emitting body in the light-emitting body array is used to emit a light beam of a wavelength band to be measured in the light source light, and the light beams of different wavelength bands to be measured do not overlap in space. The light-emitting body array may include a light-emitting diode array or a laser diode array.

[0046] In another altered embodiment, the light source includes a wavelength conversion material array and a light emitting diode or a laser diode, the wavelength conversion material array includes a plurality of wavelength conversion units made of different materials arranged in an array, each wavelength conversion unit is used to generate a light beam in a wavelength band to be measured in the light of the light source under the excitation of the light emitted by the light emitting diode or the laser diode, and the wavelength conversion material array may include quantum dots made of different materials.

[0047] like Figure 1 As shown, the secondary diffracted light is used as a light source to illuminate the modulation device 115, and the intermediate image A is imaged on the incident surface of the modulation device 115 through the imaging optical system 113, wherein the imaging optical system 113 may include multiple lenses and reflectors.

[0048] The modulation device 115 has a high degree of integration, and thus is conducive to the miniaturization design of the spectrometer 100. In this embodiment, the spectrometer 100 is portable. It is understandable that in other modified embodiments, the spectrometer 100 is not limited to being portable. The modulation device 115 includes a modulation area for receiving light from a light source and modulating the light from the light source according to modulation data. In this embodiment, the modulation area is square or strip-shaped, and the modulation area includes the above-mentioned multiple modulation sub-areas, each modulation sub-area is a part of the modulation area, and is used to receive the light source light beam emitted from the corresponding pixel, that is, each modulation sub-area also corresponds to a light source light beam of a wavelength band to be measured.

[0049] Each wavelength encoding data generated by the control device 116 has multiple data bits to distinguish light beams of different wavelength bands to be measured in the light source light, and each light beam corresponds to unique wavelength encoding data, so that it is convenient for the receiving system 130 to determine the wavelength band of the target light according to the wavelength encoding data. The modulation device 115 is provided with at least one micro-reflector in each modulation sub-area, and the micro-reflector in each modulation sub-area sequentially controls the proportion of the light beam of the corresponding wavelength band to be measured as the first detection light according to the numerical value of each data bit of the corresponding wavelength encoding data in the modulation data. For example, the control device encodes the light source light in binary, that is, the wavelength encoding data is binary data. In order to distinguish 100 wavelength bands to be measured, the wavelength encoding data needs to have at least 7 data bits (27=128>100). Assuming that the wavelength encoding data received by a modulation sub-area is 1000000, the micro-reflectors in the first sub-area can control the proportion of the emitted light as the first detection light according to the numerical value (1 or 0) in each data bit in the wavelength encoding data in the order from left to right. For the data bits 1 and 0, the proportion of the light emitted by the micro-reflectors in the modulation sub-area as the first detection light is different. For example, for the data bit 1, the proportion of the modulated sub-beam emitted by the micro-reflectors in the modulation sub-area as the first detection light is 100%, and for the data bit 0, the proportion of the light emitted by the micro-reflectors in the modulation sub-area as the first detection light is 0, that is, for the data bit 1, the modulated sub-beam emitted by the micro-reflectors in the modulation sub-area is completely emitted as the first detection light, and for the data bit 0, the light emitted by the micro-reflectors in the modulation sub-area is not emitted as the first detection light.

[0050] In this embodiment, each modulation sub-area includes 100 micro-reflectors, and all of the 100 micro-reflectors in each modulation sub-area are used to modulate the light source light of a specific wavelength band to be measured, and control the proportion of the received light source light emitted as the first detection light. In other embodiments, in at least some of the modulation sub-areas, at least some of the modulation units are used to control the proportion of the light beam of the corresponding wavelength band to be measured converted into the first detection light according to the value of each data bit of the corresponding wavelength encoding data. For example, 100 modulation units are arranged in each modulation sub-area. Assuming that the wavelength coding data of one waveband to be measured is 1000100, and the wavelength coding data of another waveband to be measured is 1000001, when encoding the light source light of the waveband to be measured coded as 1000100, 90 of the 100 micromirrors are used, and the intensity of the first detection light emitted by the modulation sub-area becomes 9 / 10 of the incident light source light, and when encoding the light source light of the waveband to be measured with the wavelength coding data of 1000001, 50 of the 100 micromirrors are used, and the intensity of the first detection light emitted by the modulation sub-area becomes 1 / 2 of the incident light source light. By controlling the number of modulation units started (used to modulate the incident light source light) in each modulation sub-area, the coding intensity of the light beam can be increased, thereby further improving the recognition degree of the light beam signals of different wavebands to be measured. The above-mentioned 100 modulation units correspond to one modulation area, and can have a relatively rich modulation combination involved in modulating the light source light. This method of modulating light of different wavelengths by using different numbers of micromirrors in each modulation sub-region is not only applicable to this embodiment, but also to other embodiments of the present invention.

[0051] For MEMS, each modulation unit is a micro-mirror with multiple stable states. In a three-dimensional MEMS, the micro-mirror can arbitrarily adjust the posture of the micro-mirror in three-dimensional space. In this embodiment, the modulation device 115 is a two-dimensional MEMS, that is, the micro-mirror in the modulation device 115 can rotate the micro-mirror within the range defined by the two-dimensional coordinate system, thereby adjusting the angle of the outgoing light. When the micro-mirror is in different stable states, the outgoing angle of the light beam corresponding to the measured band is different, resulting in different proportions of conversion into the first detection light.

[0052] The multiple modulated sub-beams emitted by the modulation device 115 are unevenly distributed in space, the wavelength distribution is also uneven, and they also carry data coding. In order to reduce the component cost and complexity of the back-end receiving system 130, among these three uneven characteristics, data coding is selected as the detection target parameter of the receiving system 130. The wavelength of each modulated sub-beam can be derived from the data coding. To this end, there is no need to maintain the uneven spatial distribution of modulated sub-beams in different bands. The transmitting system 110 includes a light homogenizing device 117, and the first detection light emitted by the modulation device 115 is used to irradiate the target to be measured after being homogenized by the light homogenizing device 117. The transmitting system 110 also includes a light splitting and combining device 114, which is used to guide the light source light emitted by the imaging optical system 113 to be incident on the modulation device 115, and guide the first detection light emitted by the modulation device 115 to be incident on the light homogenizing device 117.

[0053] After the multiple modulated sub-beams emitted by the modulation device 115 pass through the light homogenization device 117, they become the first detection light with uniform spatial distribution. The uniformly mixed first detection light is irradiated on the target P to be measured, which can improve the uniformity of the first detection light after being reflected by the target P to be measured, and avoid the randomness and uncertainty of the detection intensity distribution caused by the uneven spatial distribution. The light homogenization device 117 can include optical structures such as an optical integrator rod, a lens, and a compound eye lens.

[0054] The micro-mirrors in each modulating sub-area are in a corresponding steady state according to the value of each data bit of the corresponding wavelength-coded data, thereby controlling the proportion of an emitted modulated sub-beam incident on the light homogenizing device 117, that is, controlling the proportion of the emitted modulated sub-beam emitted as the first detection light. In this embodiment, the modulation device 115 is a digital micromirror device (DMD) belonging to a two-dimensional MEMS device. The DMD includes a plurality of micromirrors arranged in an array. Each micromirror has two stable states, namely a first stable state (on state) and a second stable state (off state). When the micromirror is in the first stable state, the angle of the emitted light is +12° (or other angles), and the modulated sub-beams emitted by the micromirror corresponding to the measured band are all incident on the homogenizing device 117, and the proportion of the modulated sub-beams emitted as the first detection light is 100%; when the micromirror is in the second stable state, the angle of the emitted light is -12°, and the modulated sub-beams emitted by the micromirror corresponding to the measured band are incident outside the homogenizing device 117, and the proportion of the modulated sub-beams emitted as the first detection light is 0. For mature DMD products, the time that the micromirror is in each steady state is about 20μs. Taking 20μs as the time for encoding one bit of data, it only takes about 0.14ms to encode 7 bits of data in the wavelength-encoded data.

[0055] The light source includes N light beams of the wavelength band to be measured. The control device 116 generates a timing coded data for each detection of the target P to be measured. The modulation device 115 modulates the time period of the light source according to the timing coded data as a modulation period. The modulation period includes N modulation time periods. The modulation device 115 is used to modulate the light beam corresponding to the wavelength band to be measured using the data in different data bits in the wavelength coded data in different modulation time periods.

[0056] In one embodiment, N=100, the light source includes 100 light beams of the wavelength band to be measured, the modulation device 115 includes 100 modulation sub-areas, the modulation cycle includes 100 equally distributed modulation time periods, the modulation time periods correspond to the wavelength band to be measured one by one, and in each modulation cycle, the modulation device emits modulated sub-beams of different wavelength bands to be measured in different modulation time periods as the first detection light. Figure 3 In this embodiment, the corresponding modulation signal Sij is a pulse signal, i and j are integers from 1 to 10, corresponding to the modulation sub-areas numbered 1-100, that is, the modulation signal Sij corresponding to the modulation sub-area numbered ij. The modulated sub-beam emitted by each modulation sub-area only in a corresponding modulation period Δt is completely emitted as the first detection light, and the modulation period Δt corresponding to each modulation sub-area is different.

[0057] For the sake of example, if N=4, the modulation device 115 includes 4 modulation sub-areas, and the modulation cycle T includes 4 modulation time periods Δt. Therefore, in the first modulation time period Δt in the cycle T, only the light emitted from the first modulation sub-area is incident on the light homogenizing device 117 and is completely emitted as the first detection light. It can be understood that in each modulation time period Δt in the cycle T, only a modulated sub-beam of a measured band emitted by a modulation sub-area is emitted as the detection light. Therefore, the receiving system 130 can only detect the influence of a detection light beam belonging to a measured band on the emitted light intensity of the target P to be measured at a time, which is beneficial to improving the efficiency and accuracy of the receiving system 130 in identifying the light beam band.

[0058] That is, in this mode of emitting the first detection light, only one modulated sub-beam emitted in a modulation period Δt in each modulation sub-area in the modulation period T is completely used as the first detection light, and the modulated sub-beams emitted in other modulation periods Δt are not used as the first detection light. In an embodiment of the present invention having 100 wavelength bands to be measured, only the first detection light of one wavelength band to be measured is emitted in each modulation period.

[0059] like Figure 4 As shown, in another embodiment, the modulation signal Sij is obtained by the wavelength encoding data to form a step pulse, and the variation curve of the modulation signal Sij over time is as shown in Figure 4As shown, in this embodiment, N=100, i and j are both integers from 1 to 10. In a modulation period in each modulation cycle, the modulation device increases or decreases a modulated sub-beam of a wavelength band to be measured as the first detection light to be emitted. That is, in a modulation cycle T, the modulated sub-beams emitted from different modulation sub-areas are sequentially emitted as the first detection light, and the time when the modulated sub-beams emitted from different modulation sub-areas start to be emitted as the first detection light is different.

[0060] exist Figure 4 In the illustrated embodiment, the modulated sub-beam emitted from the first modulation period Δt by the modulation sub-region numbered 11 is emitted as the first detection light, i.e., is incident on the light homogenizing device 117. The modulated sub-beam emitted from the second modulation period Δt by the modulation sub-region numbered 12 is emitted as the first detection light, and the modulated sub-beam emitted from the (i-1)×10+jth modulation period Δt by the modulation sub-region numbered ij is emitted as the first detection light.

[0061] For the sake of example, if N=4, the modulation device 115 includes 4 modulation sub-areas, the modulation period T includes 4 modulation time periods, and in each modulation time period, the first detection light has one more light beam of the wavelength band to be measured, which is beneficial to improve the accuracy of the intensity ratio of the first detection light beam of the receiving system 130. In a modified implementation, in one modulation time period in each modulation cycle, the modulation device reduces a modulated sub-beam of the wavelength band to be measured as the first detection light to be emitted.

[0062] The above two modulation methods of emitting modulated sub-beams of different to-be-measured wavelength bands in different modulation time periods are not limited to being applied to the first embodiment of the present invention, but may also be applied to other embodiments.

[0063] like Figure 1 As shown, the first detection light is irradiated on the target P to be measured, and the target P to be measured emits the first target light under the irradiation of the first detection light. The first target light includes the first detection light reflected by the target P to be measured, and the first target light is finally collected by the receiving system 130.

[0064] The receiving system 130 determines the wavelength band range to which the light beam included in the received target light belongs, as well as the absorption characteristics and / or reflection characteristics of the target to be measured for light beams in different wavelength bands to be measured based on the relationship between the intensity of the detected target light and time (for example, detection light-no detection light-detection light-no detection light...) and multiple wavelength encoding data, where 1 in the wavelength encoding data corresponds to detection light and 0 corresponds to no detection light.

[0065] The receiving system 130 may include a detector 131 and a data processor 132, and may also include a slit, a light shaping device, etc. The slit, the light shaping device, etc. project the processed light spot onto the detector 131. The detector 131 is used to convert the incident light signal, especially the light intensity of the incident target light, into an electrical signal, and the detector 131 may be a PIN photodetector. After the detector 131 converts the light intensity signal of the target light into an electrical signal, the electrical signal representing the light intensity is transmitted to the data processor 132, and the data processor 132 is electrically connected to the control device 116. The data processor 132 decodes the received electrical signal representing the light intensity according to the wavelength encoding data generated by the control device 116, and obtains the data of the light reflected by the target P to be measured, thereby confirming the composition of the target P to be measured according to the known material spectrum information table. Therefore, the accuracy of the receiving system 130 in detecting the band to which the target light belongs is not limited by the wavelength range. For example, a general spectrometer can distinguish between two light beams with a wavelength difference of more than 1nm, that is, the detection accuracy is 1nm, but two light beams with a wavelength difference of less than 1nm cannot be distinguished. The spectrometer 100 provided in this embodiment can confirm the band to which the target light belongs based on the encoding and decoding method, and can distinguish between two light beams with a wavelength difference of less than 1nm, and can even distinguish between two light beams with a smaller wavelength difference, thereby greatly improving the detection accuracy of the spectrometer.

[0066] As described above, the wavelength coded data is binary data, and the receiving system 130 is used to receive the relationship between the light intensity of the first target light emitted by the target P to be measured, including the reflected first detection light, and the time variation, as well as the multiple wavelength coded data, to determine the light beams of each waveband to be measured included in the received first target light, and the absorption characteristics and / or reflection characteristics of the target to be measured for the light beams of different wavebands to be measured.

[0067] In one embodiment, the control device 116 is also used to generate a plurality of verification data corresponding to a plurality of wavelength bands to be measured; a plurality of modulation sub-areas also modulate the light source light of the corresponding wavelength band to be measured according to the corresponding wavelength coding data and obtain a second detection light with corresponding verification data information, thereby realizing the encoding of the light source light by the modulation device, and the second detection light is transmitted along the second direction and irradiated to the surface of the target to be measured; and the data processor 132 in the receiving system 130 also determines the light beams of each wavelength band to be measured included in the received second target light, and the absorption characteristics and / or reflection characteristics of the target to be measured for the light beams of different wavelength bands to be measured, according to the relationship between the light intensity of the second target light including the reflected second detection light emitted by the target to be measured P and the multiple verification data. The verification data is obtained by inverting each bit of the corresponding wavelength coding data, and the second detection light has verification data information corresponding to the verification data. Detecting the target to be measured P by the additional second detection light is conducive to improving the signal-to-noise ratio of the receiving system 130.

[0068] Specifically, each wavelength-encoded data has multiple data bits, and the modulation device 115 is provided with at least one micro-reflector in each modulation sub-area. At least part of the modulation units in each modulation sub-area sequentially control the ratio of the first detection light and the second detection light corresponding to the measured band according to the numerical value of each data bit of the corresponding wavelength-encoded data.

[0069] The modulation unit is a micro-mirror with multiple stable states. When the micro-mirror is in different stable states, the proportion of the first detection light corresponding to the measured band emitted is different, and when the micro-mirror is in different stable states, the proportion of the second detection light corresponding to the measured band emitted is different. The micro-mirror in each modulation sub-area is in the corresponding steady state in sequence according to the value of each data bit in the corresponding wavelength encoding data.

[0070] Specifically, the detection light emitted by the modulation device 115 includes a first detection light corresponding to the wavelength encoding data and a second detection light corresponding to the verification data; the modulated sub-beam emitted when the micro-reflector is in the first stable state is emitted as the first detection light, and the modulated sub-beam emitted when the micro-reflector is in the second stable state is emitted as the second detection light. The micro-reflector has a first stable state and a second stable state. When the micro-reflector is in the first stable state, the proportion of the first detection light emitted by the micro-reflector is 100%, and the proportion of the second detection light emitted by the micro-reflector is 0%; when the micro-reflector is in the second stable state, the proportion of the first detection light emitted by the micro-reflector is 0%, and the proportion of the second detection light emitted by the micro-reflector is 100%. For example, if the wavelength encoding data corresponding to the first detection light is "1101010", the verification data corresponding to the second detection light is "0010101", and the state of the micro-reflector coded modulated sub-beam is "first stable state-first stable state-second stable state-first stable state-second stable state-first stable state-second stable state". That is, the micro-reflector in the modulation device 115 has different angles of emitted light in the first stable state and the second stable state, the light splitting and combining device 114 is arranged in the +12° direction of the micro-reflector, and the first detection light emitted by the micro-reflector in the first stable state passes through the light splitting and combining device 114 and the light homogenizing device 117 in sequence and then irradiates the surface of the target P to be measured. The transmitting system 110 also includes a guiding element and a second light homogenizing device arranged in the -12° direction of the micro-reflector. The second detection light emitted by the micro-reflector in the second stable state passes through the guiding element and the second light homogenizing device in sequence and then irradiates the surface of the target P to be measured. The first detection light and the second detection light are irradiated to the surface of the target to be measured along different directions. The target to be measured generates a first target light and a second target light respectively under the irradiation of the first detection light and the second detection light. The first target light and the second target light are transmitted along different directions and collected by the receiving system 130.

[0071] Accordingly, the receiving system 130 includes a first receiving subsystem and a second receiving subsystem. The first receiving subsystem is used to receive the first target light and decode the first target light according to the wavelength encoding data. The second receiving subsystem is used to receive the second target light and decode the second target light according to the verification data.

[0072] The spectrometer 100 performs identifiable encoding on the light source light and obtains the detection light, which is irradiated onto the target P to be measured, and decodes the target light emitted by the target P to be measured through the receiving system 130, thereby accurately determining the absorption characteristics and / or reflection characteristics of light beams of different wavelengths and determining the composition of the target to be measured. The spectrometer 100 has the advantages of high precision and accuracy in the wavelength range of the detection light beam.

[0073] See also Figure 5 In a second embodiment of the present invention, a spectrometer 200 is provided. The spectrometer 200 includes a transmitting system 210 and a receiving system 230. The transmitting system includes a light emitting unit 211, a dispersion component 212, and an imaging optical system 213. The main difference between the spectrometer 200 and the spectrometer 100 is that the first diffraction element 2121 in the dispersion component 212 is a reflective grating, and the second diffraction element 2122 is a transmissive grating. Accordingly, the transmitting system 210 also includes a reflective element 218. The wide-spectrum light emitted by the light emitting unit 211 is sequentially reflected by the reflective element 218, reflected by the first diffraction element 2121, and transmitted by the second diffraction element 2122 before being incident on the imaging optical system 213. The use of the reflective first diffraction element 2121 in the spectrometer 200 is conducive to shortening the transmission system as needed. Figure 5 The horizontal dimension is conducive to the miniaturization design of the spectrometer 200. It can be understood that the second diffraction element 2122 can also be a reflective grating.

[0074] It should be noted that within the scope of the spirit or basic features of the present invention, the specific schemes in each implementation manner can be mutually applicable. In order to save space and avoid repetition, they will not be described here in detail.

[0075] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple devices stated in the device claim can also be implemented by the same device or system through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A spectrometer, characterized in that: include: Launch system, including: A control device, used to generate a plurality of wavelength encoding data corresponding to the plurality of wavelength bands to be measured and generate a plurality of verification data corresponding to the plurality of wavelength bands to be measured; A light source, configured to emit light source light, wherein the light source light includes light beams of the plurality of wavelength bands to be measured, and light beams of light source light of different wavelength bands to be measured are spatially separated from each other; and A modulation device, comprising a micromirror array including a plurality of micromirrors, having a plurality of modulation sub-areas, each modulation sub-area corresponding to a wavelength band to be measured and a wavelength encoding data, the plurality of modulation sub-areas modulating the light source light of the corresponding wavelength band to be measured according to the corresponding wavelength encoding data and obtaining a first detection light having corresponding wavelength encoding data information and a second detection light having corresponding verification data information, thereby realizing the encoding of the light source light by the modulation device, the first detection light is transmitted along a first direction and irradiated to a surface of a target to be measured, and the second detection light is transmitted along a second direction and irradiated to the surface of a target to be measured; and A receiving system is used to determine the light beams of various wavelength bands to be measured included in the received first target light, and the absorption characteristics and / or reflection characteristics of the target to be measured for the light beams of different wavelength bands to be measured, based on the relationship between the light intensity of the first target light including the reflected first detection light emitted by the target to be measured and the time variation and the multiple wavelength encoding data, and determine the light beams of various wavelength bands to be measured included in the received second target light, and the absorption characteristics and / or reflection characteristics of the target to be measured for the light beams of different wavelength bands to be measured, based on the relationship between the light intensity of the second target light of the reflected second detection light and the time variation and the multiple verification data.

2. The spectrometer according to claim 1, wherein the wavelength encoding data is binary data, and the verification data is obtained by inverting each bit of the corresponding wavelength encoding data.

3. The spectrometer according to claim 2, characterized in that Each wavelength-encoded data has multiple data bits, and the modulation device is provided with at least one micro-reflector in each modulation sub-area. At least part of the modulation units in each modulation sub-area sequentially control the ratio of the first detection light and the second detection light corresponding to the measured band according to the numerical value of each data bit of the corresponding wavelength-encoded data.

4. The spectrometer according to claim 3, characterized in that The modulation unit is a micro-mirror with multiple stable states. When the micro-mirror is in different stable states, the proportion of the first detection light corresponding to the measured band emitted is different, and when the micro-mirror is in different stable states, the proportion of the second detection light corresponding to the measured band emitted is different. The micro-mirror in each modulation sub-area is in the corresponding stable state in sequence according to the value of each data bit in the corresponding wavelength encoding data.

5. The spectrometer according to claim 4, characterized in that The micro-reflector has a first stable state and a second stable state, When the micro-reflector is in the first stable state, the proportion of the first detection light emitted by the micro-reflector is 100%, and the proportion of the second detection light emitted by the micro-reflector is 0%; When the micro-reflector is in the second stable state, the proportion of the first detection light emitted by the micro-reflector is 0%, and the proportion of the second detection light emitted by the micro-reflector is 100%.

6. The spectrometer according to claim 5, characterized in that The receiving system includes a first receiving subsystem and a second receiving subsystem. The first receiving subsystem is used to receive the first target light and decode the first target light according to the wavelength encoding data. The second receiving subsystem is used to receive the second target light and decode the second target light according to the verification data.

7. The spectrometer according to claim 1, characterized in that The light source includes N light beams of the wavelength band to be measured, the control device generates a timing coded data for each detection of the target to be measured, the modulation device modulates the light source light according to the timing coded data for a time period as a modulation period, the modulation period includes N modulation time periods, and the modulation device is used to modulate the light beam corresponding to the wavelength band to be measured using data in different data bits in the wavelength coded data in different modulation time periods.

8. The spectrometer according to claim 7, characterized in that Each modulation cycle includes a plurality of modulation time periods corresponding to the plurality of wavebands to be measured. In each modulation cycle, the modulation device emits modulated sub-beams of different wavebands to be measured in different modulation time periods as first detection light.

9. The spectrometer according to claim 7, characterized in that: Each modulation cycle includes a plurality of modulation time periods corresponding one-to-one to a plurality of wavelength bands to be measured. In a modulation time period in each modulation cycle, the modulation device increases or decreases a modulated sub-beam of a wavelength band to be measured as the first detection light to be emitted.

10. The spectrometer according to claim 1, characterized in that: The light source includes a light-emitting unit and a dispersion component, wherein the light-emitting unit is used to generate broadband light, the broadband light includes a plurality of light beams of to-be-measured wavelength bands that overlap with each other in space, and after the broadband light passes through the dispersion component, light source light is obtained in which the light beams of different to-be-measured wavelength bands are spatially separated from each other.

11. The spectrometer according to claim 10, characterized in that The dispersion component includes a first diffraction element and a second diffraction element. The broad-spectrum light passes through the first diffraction element and the second diffraction element in sequence to obtain first-order diffraction light and second-order diffraction light respectively. The first-order diffraction light includes a plurality of light beams of different bands spaced apart from each other in space along a first direction. A light beam of each band in the first-order diffraction light is converted into a light beam of a part of the to-be-measured bands in a plurality of to-be-measured bands spaced apart from each other along a second direction in the second-order diffraction light. The first direction is different from the second direction. The second-order diffraction light is used as the light source light.

12. The spectrometer according to claim 11, characterized in that The first diffraction element and the second diffraction element are both transmission gratings.

13. The spectrometer according to claim 11, characterized in that The first diffraction element is a reflective grating, and the second diffraction element is a transmissive grating.

14. The spectrometer according to any one of claims 1 to 13, characterized in that: The transmitting system further comprises a light homogenizing device, and the first detection light or the second detection light emitted by the modulation device is used to illuminate the target to be detected after being homogenized by the light homogenizing device.

15. The spectrometer according to any one of claims 1 to 13, characterized in that: The light source comprises a light-emitting body array, and each light-emitting body in the light-emitting body array is used for emitting a light beam in a wavelength band to be measured in the light source light.

16. The spectrometer according to claim 15, characterized in that The light-emitting body array includes a light-emitting diode array or a laser diode array.

17. The spectrometer according to any one of claims 1 to 13, characterized in that: The light source includes a wavelength conversion material array and a light emitting diode or a laser diode. The wavelength conversion material array includes a plurality of wavelength conversion units made of different materials arranged in an array. Each wavelength conversion unit is used to generate a light beam of a wavelength band to be measured in the light of the light source under the excitation of the light emitted by the light emitting diode or the laser diode.

18. The spectrometer according to any one of claims 1 to 13, characterized in that: The light source is infrared light.

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