CN112611456A

CN112611456A - Spectrometer

Info

Publication number: CN112611456A
Application number: CN201910882552.2A
Authority: CN
Inventors: 巫英坚; 林学春; 米麟
Original assignee: Shenzhen Zhongguang Industrial Technology Research Institute
Current assignee: Shenzhen Zhongguang Industrial Technology Research Institute
Priority date: 2019-09-18
Filing date: 2019-09-18
Publication date: 2021-04-06
Also published as: WO2021052144A1

Abstract

The invention provides a spectrometer comprising: a transmission system, comprising: the control device is used for generating a plurality of wavelength coding data which correspond to a plurality of to-be-tested wave bands one by one; the light source is used for emitting light source light, the light source light comprises light beams of the multiple bands to be measured, and the light beams of the light source light of different bands to be measured are separated from each other in space; the modulation device is provided with a plurality of modulation sub-regions, the modulation sub-regions modulate light source light corresponding to a wave band to be detected according to corresponding wavelength coding data to obtain first detection light with corresponding wavelength coding data information, and the first detection light is transmitted along a first direction and irradiates the surface of a target to be detected; and the receiving system is used for determining the light beams of the received first target light in each to-be-detected wave band and the absorption characteristics and/or the reflection characteristics of the to-be-detected target to the light beams of different to-be-detected wave bands according to the relation that the light intensity of the first target light changes along with time and the plurality of wavelength encoding data.

Description

Spectrometer

Technical Field

The invention relates to the technical field of spectral analysis and detection, in particular to a spectrometer.

Background

This section is intended to provide a background or context to the specific embodiments of the invention that are recited in the claims. The description herein is not admitted to be prior art by inclusion in this section.

The spectrometer is capable of separating the composite light into narrow spectra and determining information such as the composition of the object being measured by measuring spectral characteristics of the target light (e.g., self-illumination or reflected light of the object). Depending on the principle of splitting spectra employed by spectrometers, they can be divided into two broad categories: classical spectrometers based on spatial dispersion and modulated spectrometers based on the modulation principle. Classical spectrometers include, for example, prism spectrometers, diffraction grating spectrometers, interference spectrometers, and the like; modulation spectrometers include, for example, fourier transform spectrometers, hadamard transform spectrometers, grating modulation spectrometers, and the like.

At present, the spectrometer is widely applied to the fields of biochemistry, food sanitation, environmental detection, space detection and the like. In recent years, with the improvement of living standard, people pay more attention to food safety, a spectrometer can detect pesticide residues on the surfaces of fruits and vegetables, and the spectrometer is required to be as small as possible from the viewpoint of portability. However, since the size is reduced and it is often difficult to consider the detection accuracy, there is a need for a portable spectrometer having a small size and high detection accuracy.

Disclosure of Invention

The invention provides a spectrometer comprising: a transmission system, comprising:

a transmission system, comprising: the control device is used for generating a plurality of wavelength coding data which correspond to a plurality of to-be-tested wave bands one by one; the light source is used for emitting light source light, the light source light comprises a plurality of light beams of the wave bands to be measured, and the light beams of the light source light of different wave bands to be measured are separated from each other in space; the modulation device comprises a micro mirror array comprising a plurality of micro mirrors, and is provided with a plurality of modulation sub-regions, each modulation sub-region corresponds to a to-be-detected wave band and a wavelength coding data, the plurality of modulation sub-regions modulate the light source light of the corresponding to-be-detected wave band according to the corresponding wavelength coding data and obtain first detection light with corresponding wavelength coding data information, so that the modulation device codes the light source light, and the first detection light is transmitted along a first direction and irradiates the surface of a target to be detected; and the receiving system is used for determining the light beams of all the bands to be detected included in the received first target light and the absorption characteristics and/or the reflection characteristics of the target to be detected on the light beams of different bands to be detected according to the relation of the change of the light intensity of the first target light which comprises the reflected first detection light and is emitted by the target to be detected along with time and the plurality of wavelength encoding data.

In one embodiment, the control device is further configured to generate a plurality of check data corresponding to a plurality of bands to be measured one by one; the modulation subareas also modulate the light source light corresponding to the to-be-detected waveband according to the corresponding wavelength coding data and obtain second detection light with corresponding verification data information, so that the modulation device can encode the light source light, and the second detection light is transmitted along a second direction and irradiates the surface of the to-be-detected target; and the receiving system also determines the light beams of each wave band to be detected contained in the received second target light and the absorption characteristics and/or the reflection characteristics of the light beams of different wave bands to be detected of the target to be detected according to the relation of the light intensity of the second target light which comprises the reflected second detection light and is emitted by the target to be detected along with the change of time and a plurality of verification data.

In one embodiment, the wavelength-encoded data is binary data, and the check data is inverted from each bit of data corresponding to the wavelength-encoded data.

In one embodiment, each wavelength-coded data has a plurality of data bits, the modulation device is provided with at least one micro mirror in each modulation subarea, and at least part of the modulation units in each modulation subarea sequentially control the proportion of the first detection light and the second detection light which emit the corresponding wavelength band to be detected according to the value of each data bit of the corresponding wavelength-coded data. If each modulation sub-region adopts different numbers of micro-mirrors, the light intensity coding is further carried out on the wave band to be detected, and the efficiency and the accuracy of the receiving system for identifying the wave band of the light beam are improved.

In an embodiment, the modulation unit is a micro-mirror having a plurality of stable states, the proportion of the first detection light emitted by the micro-mirror in the corresponding wavelength band to be measured is different when the micro-mirror is in different stable states, the proportion of the second detection light emitted by the micro-mirror in the corresponding wavelength band to be measured is different when the micro-mirror is in different stable states, and the micro-mirror in each modulation sub-region is in the corresponding stable state in sequence according to the value of each data bit in the corresponding wavelength encoding data.

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

In one embodiment, the receiving system includes a first receiving subsystem for receiving the first target light and decoding the first target light according to the wavelength-coded data, and a second receiving subsystem for receiving the second target light and decoding the second target light according to the verification data.

In one embodiment, the light source light includes N light beams in a wavelength band to be measured, the control device generates a time sequence encoding data for each detection of the target to be measured, the modulation device modulates a time period of the light source light into a modulation cycle according to the time sequence encoding data, the modulation cycle includes N modulation periods, and the modulation device is configured to modulate the light beams in the corresponding wavelength band to be measured with data in different data bits in the wavelength encoding data in different modulation periods.

In one embodiment, each modulation cycle includes a plurality of modulation periods corresponding to a plurality of wavelength bands to be measured, and in each modulation cycle, the modulation device emits modulated sub-beams of different wavelength bands to be measured as the first detection light in different modulation periods. Therefore, the receiving system can only detect the influence of the detection light beams belonging to one to-be-detected wave band on the emergent light intensity of the to-be-detected target at one moment, and the efficiency and the accuracy of the receiving system for identifying the wave bands of the light beams are improved.

In one embodiment, the light source includes a light emitting unit and a dispersion component, where the light emitting unit is configured to generate wide-spectrum light, the wide-spectrum light includes light beams in a plurality of bands to be measured that are spatially overlapped with each other, and the wide-spectrum light passes through the dispersion component to obtain light source light in which the light beams in different bands to be measured are spatially separated from each other.

In one embodiment, the dispersion assembly includes a first diffraction element and a second diffraction element, the wide-spectrum light sequentially passes through the first diffraction element and the second diffraction element to respectively obtain first-order diffracted light and second-order diffracted light, the first-order diffracted light includes a plurality of light beams with different wavelength bands spaced apart from each other in a first direction, one light beam in each wavelength band in the first-order diffracted light is converted into a light beam with a wavelength band to be measured in a plurality of wavelength bands to be measured spaced apart from each other in a second direction in the second-order diffracted light, the first direction is different from the second direction, and the second-order diffracted light is used as light source light.

In one embodiment, the first diffractive element and the second diffractive element are both transmissive gratings.

In one embodiment, the first diffractive element is a reflective grating and the second diffractive element is a transmissive grating.

In one embodiment, the emission system further includes a light uniformizing device, and the first detection light or the second detection light emitted by the modulation device is used for being uniformized by the light uniformizing device and then irradiated to the object to be measured. The uniformly mixed detection light is irradiated on the target to be detected, so that the uniformity of the detection light reflected by the target to be detected can be improved, and the influence on the randomness and the uncertainty of detection intensity distribution due to nonuniform spatial distribution is avoided.

In one embodiment, the light source includes an array of light emitters, each light emitter in the array of light emitters being configured to emit a light beam in a wavelength band of interest in the light source light.

In one embodiment, the array of light emitters comprises an array of light emitting diodes or an array of laser diodes.

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 for generating a light beam of a wavelength band to be measured in the light source light under the excitation of light emitted by the light emitting diode or the laser diode.

In one embodiment, the source light is infrared light.

The spectrometer provided by the invention can be used for carrying out identifiable coding on light source light by using a modulation device (MEMS) to obtain detection light, the detection light is irradiated onto a target to be detected, and target light emitted by the target to be detected is decoded by using a receiving system, so that the absorption characteristics and/or the reflection characteristics of light beams with different wavelengths are accurately determined, and the components of the target to be detected are determined.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments/modes of the present invention, the drawings needed to be used in the description of the embodiments/modes are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments/modes of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a spectrometer according to a first embodiment of the present invention.

Fig. 2 is a schematic view of the intermediate image shown in fig. 1.

Fig. 3 is a timing diagram of a modulation signal.

Fig. 4 is a timing diagram of another modulation signal.

Fig. 5 is a schematic structural diagram of a spectrometer according to a second embodiment of the present invention.

Description of the main elements

Spectrometer	100、200
		Transmitting system	110、210
Light emitting unit	111、211
		Dispersive component	112、212
First diffraction element	1121、2121
		Second diffractive element	1122、2122
Imaging optical system	113、213
		Intermediate image	A
Modulating signals	S11、S12、……、Sij、……、Smn
		Period of time	T
Modulation period	Δt
		Light splitting and combining device	114
Modulation device	115
		Control device	116
Light source	119
		Reflective element	218
Receiving system	130、230
		Detector	131
Data processor	132
		Target to be measured	P

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a detailed description of the present invention will be given below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention, and the described embodiments are merely a subset of the embodiments of the present invention, rather than a complete embodiment. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The invention provides a spectrometer, which can identify and code detection light according to a plurality of wavelength coding data, the detection light irradiates on a target to be detected, the light intensity of target light emitted by the target to be detected is detected through a receiving system, light beams of each band to be detected included in the received target light are determined according to the plurality of wavelength coding data, namely the target light is decoded through the receiving system, so that the absorption characteristics and/or the reflection characteristics of the light beams with different wavelengths are accurately determined, and the components of the target to be detected are determined. The spectrometer has the advantages of small volume and high precision and accuracy of the wavelength range of the detection light beam.

Referring to fig. 1, a spectrometer 100 according to a first embodiment of the present invention is a portable spectrometer, but is not limited to portable spectrometer in other embodiments. The spectrometer 100 includes a transmission system 110 and a reception system 130. Wherein the emitting system 110 comprises a light source 119, a modulation means 115 and a control means 116. The control device 116 is configured to generate a plurality of wavelength-encoded data corresponding to a plurality of wavelength bands to be measured, the light source 119 is configured to emit light source light, the light source light includes light beams of the plurality of wavelength bands to be measured, and the light beams of the light source light of different wavelength bands to be measured are spatially separated from each other; the modulation device 115 is configured to modulate the light source light according to the plurality of wavelength-encoded data and obtain modulated light. Specifically, the modulation device 115 has a plurality of modulation sub-regions, each modulation sub-region corresponds to a wavelength band to be measured and a wavelength-coded data, each modulation sub-region modulates the light source light in the corresponding wavelength band to be measured according to the corresponding wavelength-coded data to obtain a modulated sub-beam having information of the corresponding wavelength-coded data, and a plurality of modulated sub-beams emitted by the modulation device 115 are used as the first detection light irradiated to the target P to be measured. The receiving system 130 is configured to detect a relationship between a change with time of light intensity of a first target light emitted from the target P to be detected and including the reflected first detection light, and a plurality of wavelength-encoded data, and determine light beams of each wavelength band to be detected included in the received first target light, and absorption characteristics and/or reflection characteristics of the target to be detected on the light beams of different wavelength bands to be detected.

Specifically, the multiple bands to be measured to which the light source light emitted by the spectrometer 100 belongs are not overlapped and are parameters of the spectrometer 100 that are set in advance, or the multiple bands to be measured may be set by a user through an external input device (a mouse, a keyboard, a touch display panel, or the like) of the spectrometer 100. For simple calculation, the bandwidth of the light source light in the embodiment is 0.1 μm, and the precision of the detection wavelength range of the spectrometer can reach 1nm (i.e. the spectrometer can distinguish two lights with a wavelength difference of 1 nm), in the present invention, the bandwidth of the light source light can be equally divided into 100 bands to be measured, and the bandwidth of each band to be measured is 1 nm. The control device 116 generates wavelength-encoded data corresponding to a plurality of bands to be measured, that is, each wavelength-encoded data corresponds to one band to be measured, and the wavelength-encoded data corresponding to different bands to be measured are different. The control device 116 may randomly generate the wavelength-encoded data or obtain the wavelength-encoded data according to a predetermined algorithm or formula.

As shown in fig. 1, the light source 119 includes a light emitting unit 111 and a dispersing component 112, wherein the light emitting unit 111 is configured to generate a broad spectrum light, the broad spectrum light includes a plurality of light beams of wavelength bands to be measured, which are spatially overlapped with each other, and in one embodiment, light rays of various wavelength bands in the broad spectrum light are spatially uniformly distributed, that is, light rays of a plurality of wavelength bands to be measured are provided at a spatial point on a transmission optical path of the broad spectrum light. The broad spectrum light is preferably infrared light, and the spectrometer 100 performs molecular structure and chemical composition analysis using absorption characteristics of the substance for infrared radiation of different wavelengths. The substance is composed of atoms that vibrate constantly, and the vibration frequency of these atoms is equivalent to the vibration frequency of infrared light. When an organic matter is irradiated by infrared light, molecules absorb the infrared light to generate vibration level transition, different chemical bonds or functional groups have different absorption frequencies, each organic matter molecule only absorbs infrared spectrum consistent with the molecular vibration and rotation frequency of the organic matter molecule, and the obtained absorption spectrum is generally called infrared absorption spectrum. The infrared spectrum is analyzed, and qualitative analysis can be carried out on the substances. The content of each substance will also be reflected on the infrared absorption spectrum, and can be quantitatively analyzed according to the peak position and absorption intensity. In the present embodiment, the broad spectrum bandwidth is 0.1 μm and the wavelength range is 1.9 μm to 2.0. mu.m. The light emitting unit 111 may be a light emitting diode light source or a laser diode light source, i.e. the light emitting unit 111 may comprise a light emitting diode, a light emitting diode array, a laser diode or a laser diode array.

The dispersion component 112 is configured to perform dispersion and splitting on the incident wide-spectrum light, further, light beams of multiple bands to be measured in the wide-spectrum light are overlapped in space, and the wide-spectrum light passes through the dispersion component 112 to obtain light source light in which the light beams of different bands to be measured are separated from each other in space. In this embodiment, if the number of the bands to be measured is 100, one wide spectrum light beam is divided into 100 light beams in the light source light by the dispersion component 112, each light beam in the light source light belongs to one band to be measured, that is, the wavelength range of each light beam in the light source light is within the range of one band to be measured, different light beams in the light source light belong to different bands to be measured, that is, the dispersion component 112 is configured to divide the wide spectrum light into a plurality of light beams corresponding to the bands to be measured according to a plurality of bands to be measured.

Specifically, in the present embodiment, the dispersive element 112 includes a first diffractive element 1121 and a second diffractive element 1122. The first diffractive element 1121 and the second diffractive element 1122 are both transmissive gratings, that is, light is diffracted and transmitted by the first diffractive element 1121 and the second diffractive element 1122. In this embodiment, the first diffraction element 1121 includes a transparent substrate and a series of scribe lines formed on the substrate, and the wide-spectrum light passes through the first diffraction element 1121 to form a striped diffraction pattern. In one embodiment, the first diffraction element 1121 includes a transparent substrate and a series of stripe-shaped grooves formed on the substrate, and in another embodiment, the first diffraction element 1121 includes a metal substrate and a series of slits formed on the metal substrate. The second diffractive element 1122 can have the same or different structure as the first diffractive element 1121. The first diffractive element 1121 has m cuts and the second diffractive element 1122 has n cuts. In the present embodiment, for easy calculation, the plurality of bands to be measured are 100 bands, and m is 10.

The first diffraction element 1121 and the second diffraction element 1122 have different dispersion splitting directions, and in the present embodiment, the splitting directions of the first diffraction element 1121 and the second diffraction element 1122 are perpendicular, that is, the extending directions of the scribed lines of the first diffraction element 1121 and the second diffraction element 1122 are perpendicular to each other, that is, as shown in fig. 1, the scribed line of the first diffraction element 1121 extends in the vertical direction in fig. 1, and the scribed line of the second diffraction element 1122 extends in the direction perpendicular to the paper surface in fig. 1, it can be understood that the extending directions of the scribed lines of the first diffraction element 1121 and the second diffraction element 1122 may be different from the directions shown in fig. 1.

After the broad-spectrum light sequentially passes through the first diffraction element 1121 and the second diffraction element 1122, first-order diffraction light and second-order diffraction light are obtained respectively, the first-order diffraction light comprises a plurality of light beams with different wavelength bands which are spaced from each other along a first direction (vertical direction in fig. 1), the central wavelengths of the plurality of light beams in the first-order diffraction light are represented as λ 1 and λ 2 … … λ m, each light beam has a bandwidth Δ λ 1 … … Δ λ m, wherein Σ Δ λ i is Δ λ, and i is 1, 2, … … m. In the present embodiment, m is 10 and Δ λ is 0.1 μm, that is, the first diffraction element 1211 splits the incident one broad-spectrum light into 10 non-overlapping first-order diffracted lights, and the bandwidths of the 10 first-order diffracted lights are added to the bandwidth of the broad-spectrum light. One beam in each wavelength band in the first-order diffracted light is converted into a beam in a part of a wavelength band to be measured among a plurality of wavelength bands to be measured spaced apart from each other in the second direction (direction perpendicular to the paper surface in fig. 1) in the second-order diffracted light, i.e., each beam in the first-order diffracted light is dispersed and split by the second diffraction element 1122 to split each beam in the first-order diffracted light into a plurality of narrower wavelength bands. For example, a first light beam (center wavelength λ 1) of the first-order diffracted lights passes through the second diffraction element 1122 to obtain n light beams whose wavelength ranges are not overlapped, the center wavelengths of the light beams are λ 11 … … λ 1n, and the center wavelengths of the light beams obtained by passing all the light beams of the first-order diffracted lights through the second diffraction element 1122 are 100 light beams of λ 11 … … λ 1n, λ 21 … … λ 2n, and λ m1 … … λ mn, and the bandwidth of each light beam is λ ij, Σ Δ ij is Δ λ i, where j is 1, 2, … … n, and Σ Δ λ ij is Δ λ, where i is 1, 2, … … m, and j is 1, 2, … … n, and m is 10 in this embodiment. That is, a plurality of light beams spaced apart in the first direction in the first-order diffracted light pass through the second diffraction element 1122 to obtain a light beam array of the second diffracted light arranged in a matrix in the first direction and the second direction, wavelength ranges of different light beams in the light beam array do not overlap, each light beam belongs to a wavelength band to be measured, wavelength bands to be measured of different light beams in the light beam array are different, a two-dimensional distributed intermediate image a is formed on a transmission path of the second-order diffracted light, the intermediate image a is a two-dimensional matrix including m × n pixels, wavelength ranges of light beams irradiated to different pixels do not overlap, and a center wavelength of the second-order diffracted light irradiated to each pixel is λ ij, as shown in fig. 2.

In a modified embodiment, the light source 119 includes an array of light emitters for emitting light source light, each light emitter in the array of light emitters is for emitting 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 array of light emitters may comprise an array of light emitting diodes or an array of laser diodes.

In another modified 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 for generating a light beam of a wavelength band to be measured in the light source light under the excitation of 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.

As shown in fig. 1, the second-order diffracted light is used as light source light to irradiate 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 a plurality of lenses and mirrors.

The modulation device 115 is highly integrated and thus facilitates a compact design of the spectrometer 100, and in this embodiment the spectrometer 100 is portable, it being understood that in other variations the spectrometer 100 is not limited to being portable. The modulation means 115 comprise modulation regions for receiving the light source light and modulating the light source light in accordance with modulation data. In this embodiment, the modulation region is square or long, the modulation region includes the above-mentioned multiple modulation sub-regions, each modulation sub-region is a part of the modulation region and is configured to receive the light source light beam emitted from the corresponding pixel, that is, each modulation sub-region also corresponds to one light source light beam in a wavelength band to be measured.

Each wavelength-encoded data generated by the control device 116 has a plurality of data bits to distinguish the light beams of different wavelength bands to be measured in the source light, each light beam corresponding to a unique wavelength-encoded data, thereby facilitating the receiving system 130 to determine the wavelength band of the target light based on the wavelength-encoded data. The modulation device 115 is provided with at least one micro-mirror in each modulation sub-region, and the micro-mirror in each modulation sub-region sequentially controls the proportion of the light beam corresponding to the wavelength band to be detected as the first detection light according to the 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-encoded data is binary data, and in order to distinguish 100 wavelength bands to be measured, the wavelength-encoded data needs to have at least 7 data bits (27 ═ 128 > 100). Assuming that the wavelength-encoded data received by a sub-modulation region is 1000000, the micro-mirrors in the first sub-modulation region can control the proportion of the emergent light as the first detection light according to the value (1 or 0) in each data bit in the wavelength-encoded data from left to right, and the proportion of the emergent light of the micro-mirrors in the sub-modulation region as the first detection light is different for 1 and 0 on the data bit. For example, for 1 on a data bit, the proportion of the modulated sub-beams emitted by the micro-mirrors in the modulation sub-region as the first detection light is 100%, for 0 on the data bit, the proportion of the light emitted by the micro-mirrors in the modulation sub-region as the first detection light is 0, that is, for 1 on the data bit, the modulated sub-beams emitted by the micro-mirrors in the modulation sub-region are completely emitted as the first detection light, and for 0 on the data bit, the light emitted by the micro-mirrors in the modulation sub-region is not emitted as the first detection light.

In the present embodiment, each of the modulator sub-regions includes 100 micro mirrors, and all of the 100 micro mirrors in each of the modulator sub-regions are used to modulate the light source light of a specific wavelength band to be measured, and control the ratio of the received light source light to be emitted as the first detection light. In other embodiments, in at least part of the modulation subarea, at least part of the modulation unit is used for controlling the proportion of the light beam corresponding to the wavelength band to be detected converted into the first detection light according to the value of each data bit of the corresponding wavelength encoding data. For example, each modulation sub-region is provided with 100 modulation units, assuming that wavelength encoding data of one wavelength band to be measured is 1000100, and wavelength encoding data of another wavelength band to be measured is 1000001, when encoding light source light of a wavelength band to be measured which is 1000100, 90 of 100 micromirrors are used, then the modulation sub-region emits the intensity of first detection light to become 9/10 of incident light source light, and when encoding light source light of a wavelength band to be measured which is 1000001, 50 of 100 micromirrors are used, then the modulation sub-region emits 1/2 of first detection light whose intensity becomes incident light source light. The coded intensity of the light beams can be increased by controlling the number of the modulation units which are started (used for modulating the incident light source light) in each modulation subarea, so that the recognition degree of the light beam signals of different wave bands to be measured is further improved. The above 100 modulation units correspond to one modulation region, and can have richer modulation combinations participating in modulating the light of the light source. This way of modulating light of different wavelengths by using different numbers of micromirrors through each modulation sub-region can be applied not only to the present embodiment, but also to other embodiments of the present invention.

For MEMS, each modulation cell is a micro-mirror with multiple stable states. In the three-dimensional MEMS, the micro-mirror can adjust the posture of the micro-mirror in a three-dimensional space at will, 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 a range defined by a two-dimensional coordinate system, so as to adjust the angle of the emergent light. When the micro-reflector is in different stable states, the emergent angles of the light beams which guide and emit corresponding to the wave bands to be detected are different, so that the proportion of the light beams which are converted into the first detection light is different.

The plurality of modulated sub-beams emitted by the modulation device 115 are not uniformly distributed in space, the wavelength distribution is not uniform, and the modulated sub-beams also carry data codes, and in order to reduce the component cost and complexity of the receiving system 130 at the rear end, the data codes are selected as detection target parameters of the receiving system 130 among the three non-uniform characteristics. The wavelength of each modulated sub-beam can be derived from the data encoding. For this reason, it is not necessary to keep the spatial distribution of the modulated sub-beams of different wavelength bands uneven. The emitting system 110 includes an optical homogenizer 117, and the first detection light emitted from the modulator 115 is used for irradiating to the target to be measured after being homogenized by the optical homogenizer 117. The emitting system 110 further includes a light splitting and combining device 114, and the light splitting and combining device 114 is configured to guide the light source light emitted from the imaging optical system 113 to enter the modulating device 115, and guide the first detection light emitted from the modulating device 115 to enter the light uniformizing device 117.

The modulated sub-beams emitted by the modulation device 115 pass through the light uniformizing device 117 and become the first detection light with uniform spatial distribution, and the uniformly mixed first detection light irradiates on the object P to be detected, so that the uniformity of the first detection light reflected by the object P to be detected can be improved, and the influence of the spatial distribution on the randomness and uncertainty of detection intensity distribution can be avoided. The light homogenizing device 117 may include optical structures such as an optical integrator rod, a lens, a fly-eye lens, and the like.

The micro-mirrors in each modulation subarea are in corresponding steady states in sequence according to the value of each data bit of the corresponding wavelength-coded data, so that the proportion of the emitted modulated sub-beam to be incident on the light uniformizing device 117 is controlled, namely the proportion of the emitted modulated sub-beam as the first detection light is controlled. 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, which are 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 emergent light is +12 ° (or other angles), all of the modulated sub-light beams emitted from the Micromirror and corresponding to the wavelength band to be detected are incident to the light uniformizing Device 117, and the proportion of the emitted modulated sub-light beams as the first detection light is 100%; when the micro-mirror is in the second stable state, the angle of the emergent light is-12 °, the modulated sub-beam corresponding to the wavelength band to be detected and emitted by the micro-mirror is incident outside the light uniformizing device 117, and the proportion of the modulated sub-beam corresponding to the wavelength band to be detected as the first detection light is 0. For a mature DMD product, the time for each micromirror to stay at steady state is about 20 μ s, and with 20 μ s as the time for one bit data encoding, only about 0.14ms is required to encode 7 bits of data in the wavelength encoded data.

The light source light comprises N light beams of a to-be-detected waveband, the control device 116 generates a time sequence encoding data for each detection of a to-be-detected target P, the modulation device 115 modulates a time period of the light source light into a modulation cycle according to the time sequence encoding data, the modulation cycle comprises N modulation time periods, and the modulation device 115 is used for modulating the light beams of the corresponding to-be-detected waveband by using data in different data bits in the wavelength encoding data in different modulation time periods.

In one embodiment, N is 100, the light source light includes 100 light beams in a wavelength band to be detected, the modulation device 115 includes 100 modulation sub-regions, the modulation cycle includes 100 modulation periods that are evenly distributed, the modulation periods correspond to the wavelength band to be detected one by one, and in each modulation cycle, the modulation device emits modulated sub-beams in different wavelength bands to be detected in different modulation periods as the first detection light. Referring to fig. 3, in the present embodiment, the corresponding modulation signal Sij is a pulse signal, i and j are integers from 1 to 10, and the modulation signal used by the corresponding modulation sub-region with the number of 1-100, i.e., the modulation sub-region with the number of ij, is Sij. The modulation sub-beams emitted by each modulation sub-region only in a corresponding one of the modulation time periods Δ t are completely emitted as the first detection light, and the modulation time period Δ t corresponding to each modulation sub-region is different.

For convenience of example, if N is 4, the modulation device 115 includes 4 modulation sub-regions, and the modulation cycle T includes 4 modulation time periods Δ T, so that, in the first modulation time period Δ T in the cycle T, only the first modulation sub-region emitted light enters the light uniformizing device 117 and is completely emitted as the first detection light, it can be understood that, in each modulation time period Δ T in the cycle T, only one modulation sub-beam of the wavelength band to be detected emitted by one modulation sub-region is emitted as the detection light, so that the receiving system 130 can detect only the influence of the detection light beam belonging to one wavelength band to be detected on the emitted light intensity of the target P to be detected at one time, which is beneficial to improving the identification efficiency and accuracy of the receiving system 130 on the light beam wavelength band.

That is, in such a mode of emitting the first detection light, only one modulation sub-beam emitted by each modulation sub-region in the modulation period T is completely used as the first detection light, and the modulation sub-beams emitted by the other modulation periods Δ T are not used as the first detection light. In the embodiment of the present invention having 100 wavelength bands to be measured, only one first detection light of the wavelength band to be measured is emitted in each modulation period.

In another embodiment, as shown in fig. 4, a modulation signal Sij is obtained from wavelength-encoded data to form a step pulse, and a time-dependent change curve of the modulation signal Sij is as shown in fig. 4, in this embodiment, N is 100, and i and j are integers from 1 to 10. In one modulation period in each modulation cycle, the modulation device increases or decreases one modulated sub-beam of a wavelength band to be measured as the first detection light to be emitted. That is, in one modulation period T, the modulated sub-beams emitted from different modulation sub-regions sequentially emit as the first detection light, and the modulated sub-beams emitted from different modulation sub-regions start to emit as the first detection light at different times.

In the embodiment shown in fig. 4, the modulated sub-beam, numbered 11, of the modulated sub-region that emerges from the beginning of the first modulation period Δ t emerges as the first detection light, i.e. is incident on the light unifying means 117. The modulated sub-beam emitted from the second modulation period Δ t by the modulation sub-region denoted by reference numeral 12 is emitted as the first detection light, and the modulated sub-beam emitted from the (i-1) × 10+ j modulation period Δ t by the modulation sub-region denoted by reference numeral ij is emitted as the first detection light.

For convenience of example, if N is 4, the modulation device 115 includes 4 modulation sub-regions, and the modulation period T includes 4 modulation periods, in each of which one more light beam in the wavelength band to be measured is included in the first detection light, which is beneficial to improving the accuracy of the light intensity ratio of the first detection light beam in the receiving system 130. In a modified embodiment, the modulation device reduces the modulated sub-beams of one wavelength band to be measured as the first detection light to be emitted in one modulation period in each modulation cycle.

The two modulation methods for emitting the modulated sub-beams with different wavelength bands to be measured in different modulation periods are not limited to be applied to the first embodiment of the present invention, and can be applied to other embodiments.

As shown in fig. 1, the first detection light is irradiated on the object P to be measured, and the object 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 object P to be measured, and finally the first target light is collected by the receiving system 130.

The receiving system 130 determines the wavelength range to which the light beam included in the received target light belongs, and the absorption characteristic and/or the reflection characteristic of the target to be measured on the light beams of different wavelength bands to be measured according to the relationship of the light intensity of the detected target light (for example, detected light-no detected light-no detected light … …) with time and a plurality of wavelength-encoded data, wherein 1 in the wavelength-encoded data corresponds to detected light, and 0 in the wavelength-encoded data corresponds to no detected light.

The receiving system 130 may comprise a detector 131 and a data processor 132, and may further comprise a slit, a light shaping device, etc. A slit, a light shaping device, or the like projects the processed spot onto the detector 131. The detector 131 is used for converting an incident optical signal, particularly the light intensity of the incident target light, into an electrical signal, and the detector 131 may be a PIN photodetector. The detector 131 converts the light intensity signal of the target light into an electrical signal, and then transmits the electrical signal representing the light intensity to the data processor 132, the data processor 132 is electrically connected to the control device 116, and 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 to obtain the data of the reflected light of the target P to be detected, so as to confirm the components of the target P to be detected according to the known substance spectrum information table. Therefore, the accuracy of the receiving system 130 detecting the wavelength band to which the target light belongs is not limited by the wavelength range, for example, a general spectrometer can distinguish two beams of light with a wavelength difference of more than 1nm, that is, the detection accuracy is 1nm, and two beams of light with a wavelength difference of less than 1nm cannot be distinguished, the spectrometer 100 provided in this embodiment can confirm the wavelength band to which the target light belongs according to the encoding and decoding method, can distinguish two beams of light with a wavelength difference of less than 1nm, and can even distinguish two beams of light with a smaller wavelength difference, thereby greatly improving the detection accuracy of the spectrometer.

As described above, the wavelength-coded data is binary data, and the receiving system 130 is configured to receive a relationship that light intensity of the first target light including the reflected first detection light emitted from the target P to be detected changes with time, and the plurality of wavelength-coded data, determine the light beams of the respective wavelength bands to be detected included in the received first target light, and determine absorption characteristics and/or reflection characteristics of the target to be detected on the light beams of different wavelength bands to be detected.

In one embodiment, the control device 116 is further configured to generate a plurality of check data corresponding to a plurality of bands to be measured; the modulation subareas also modulate the light source light corresponding to the to-be-detected waveband according to the corresponding wavelength coding data and obtain second detection light with corresponding verification data information, so that the modulation device codes the light source light, and the second detection light is transmitted along a second direction and irradiates the surface of the to-be-detected target; and the data processor 132 in the receiving system 130 further determines, according to the relationship between the change with time of the light intensity of the second target light including the reflected second detection light emitted from the target P to be detected and the plurality of calibration data, the light beams of each wavelength band to be detected included in the received second target light, and the absorption characteristics and/or the reflection characteristics of the target to be detected on the light beams of different wavelength bands to be detected. The verification data is obtained by inverting the data of each bit corresponding to the wavelength coding data, and the second detection light has verification data information corresponding to the verification data. The detection of the object P to be measured by the additional second detection light is advantageous to improve the signal-to-noise ratio of the receiving system 130.

Specifically, each wavelength-encoded data has a plurality of data bits, the modulation device 115 is provided with at least one micro mirror in each modulation subregion, and at least part of the modulation units in each modulation subregion sequentially control the ratio of the first detection light and the second detection light which emit the corresponding wavelength band to be detected according to the numerical value of each data bit of the corresponding wavelength-encoded data.

The modulation unit is a micro-mirror with a plurality of stable states, the proportion of first detection light of the corresponding to-be-detected wave band emitted by the micro-mirror when the micro-mirror is in different stable states is different, the proportion of second detection light of the corresponding to-be-detected wave band emitted by the micro-mirror when the micro-mirror is in different stable states is different, and the micro-mirror in each modulation sub-region is in the corresponding stable state according to the numerical value of each data bit in the corresponding wavelength encoding data in sequence.

Specifically, the detection light emitted by the modulation device 115 includes first detection light corresponding to the wavelength-encoded data and second detection light corresponding to the verification data; the modulated sub-beams emitted when the micro-mirror is in the first stable state are emitted as first detection light, and the modulated sub-beams emitted when the micro-mirror is in the second stable state are emitted as second detection light. The micro-mirror has a first stable state and a second stable state, when the micro-mirror is in the first stable state, the proportion of first detection light emitted by the micro-mirror is 100%, and the proportion of second detection light emitted by the micro-mirror is 0%; when the micro-mirror is in the second stable state, the proportion of the first detection light emitted by the micro-mirror is 0%, and the proportion of the second detection light emitted by the micro-mirror is 100%. For example, the wavelength-encoded 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 micromirror encoding modulation sub-beam is "first stable state-second stable state-first stable state-second stable state". That is, the angles of the light emitted by the micro-mirrors in the modulation device 115 at the first stable state and the second stable state are different, the light splitting and combining device 114 is disposed in the +12 ° direction of the micro-mirrors, the first detection light emitted by the micro-mirrors at the first stable state sequentially passes through the light splitting and combining device 114 and the light uniformizing device 117 and then irradiates the surface of the target P to be measured, the emission system 110 further includes a guiding element and a second light uniformizing device disposed in the-12 ° direction of the micro-mirrors, the second detection light emitted by the micro-mirrors at the second stable state sequentially passes through the guiding element, the second light uniformizing device irradiates the surface of the target P to be measured, the first detection light and the second detection light irradiate the surface of the target P to be measured along different directions, the target to be measured correspondingly generates a first target light and a second target light under the irradiation of the first detection light and the second detection light, and the first target light and the second target light are transmitted along different directions and collected by the receiving system 130.

Correspondingly, the receiving system 130 includes a first receiving subsystem and a second receiving subsystem, the first receiving subsystem is configured to receive the first target light and decode the first target light according to the wavelength-coded data, and the second receiving subsystem is configured to receive the second target light and decode the second target light according to the verification data.

The spectrometer 100 performs identifiable coding on the light source light to obtain detection light, the detection light irradiates on the target P to be detected, and the target light emitted by the target P to be detected is decoded by the receiving system 130, so that the absorption characteristics and/or the reflection characteristics of the light beams with different wavelengths are accurately determined and the components of the target to be detected are determined, and the spectrometer 100 has the advantages of high precision and accuracy in the wavelength range of the detection light beams.

Referring to fig. 5, in a second embodiment of the present invention, a spectrometer 200 is provided, the spectrometer 200 includes an emission system 210 and a receiving system 230, the emission system includes a light emitting unit 211, a dispersion element 212 and an imaging optical system 213. The spectrometer 200 mainly differs from the spectrometer 100 in that the first diffractive element 2121 in the dispersive component 212 is a reflective grating, the second diffractive element 2122 is a transmissive grating, and accordingly, the emission system 210 further includes a reflective element 218, and the wide-spectrum light emitted from the light emitting unit 211 is incident to the imaging optical system 213 after being reflected by the reflective element 218, reflected by the first diffractive element 2121, and transmitted by the second diffractive element 2122. The use of the reflective first diffractive element 2121 in the spectrometer 200 is advantageous for shortening the lateral dimension of the emission system in fig. 5 as required, and for miniaturization of the spectrometer 200. It will be appreciated that the second diffractive element 2122 may also be a reflective grating.

It should be noted that the specific embodiments of the present invention can be applied to each other within the scope of the spirit or the basic features of the present invention, and for the sake of brevity and avoiding repetition, the details are not repeated herein.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. Several of the means recited in the apparatus claims may also be embodied by one and the same means or system in software or hardware. The terms first, second, etc. are used to denote names, but not any particular order.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A spectrometer, comprising:

a transmission system, comprising:

the control device is used for generating a plurality of wavelength coding data which correspond to a plurality of to-be-tested wave bands one by one;

the light source is used for emitting light source light, the light source light comprises light beams of the multiple bands to be measured, and the light beams of the light source light of different bands to be measured are separated from each other in space; and

the modulation device comprises a micro mirror array comprising a plurality of micro mirrors, and is provided with a plurality of modulation sub-regions, each modulation sub-region corresponds to a to-be-detected waveband and a wavelength coding data, the plurality of modulation sub-regions modulate light source light corresponding to the to-be-detected waveband according to the corresponding wavelength coding data and obtain first detection light with corresponding wavelength coding data information, so that the modulation device codes the light source light, and the first detection light is transmitted along a first direction and irradiates the surface of a target to be detected; and

and the receiving system is used for determining the light beams of the received first target light in each band to be detected and the absorption characteristics and/or the reflection characteristics of the target to be detected on the light beams in different bands to be detected according to the relation that the light intensity of the first target light which comprises the reflected first detection light and is emitted by the target to be detected changes along with time and the plurality of wavelength encoding data.

2. The spectrometer of claim 1, wherein the control device is further configured to generate a plurality of calibration data corresponding to a plurality of bands under test one to one;

the modulation sub-regions also modulate the light source light corresponding to the to-be-detected waveband according to the corresponding wavelength coding data to obtain second detection light with corresponding verification data information, and the second detection light is transmitted along a second direction and irradiates the surface of the to-be-detected target; and

the receiving system also determines the light beams of each to-be-detected wave band included by the received second target light and the absorption characteristics and/or the reflection characteristics of the to-be-detected target to the light beams of different to-be-detected wave bands according to the relation of the change of the light intensity of the second target light which is emitted by the to-be-detected target and comprises the reflected second detection light along with time and the plurality of check data.

3. The spectrometer of claim 2, wherein the wavelength-encoded data is binary data, and the verification data is inverted from each bit of data corresponding to the wavelength-encoded data.

4. A spectrometer as claimed in claim 3 wherein each wavelength encoded data has a plurality of data bits, the modulation means is provided with at least one micro-mirror in each sub-modulation region, at least some of the modulation cells in each sub-modulation region sequentially controlling the ratio of the first detected light and the second detected light exiting the corresponding wavelength band to be measured in accordance with the value of each data bit corresponding to the wavelength encoded data.

5. The spectrometer of claim 4, wherein the modulation unit is a micro-mirror having a plurality of stable states, the micro-mirror emitting different proportions of the first detection light in the corresponding wavelength band under test when in different stable states, and the micro-mirror emitting different proportions of the second detection light in the corresponding wavelength band under test when in different stable states, the micro-mirror in each sub-modulation region being in the corresponding stable state in turn according to the value of each data bit in the corresponding wavelength encoded data.

6. The spectrometer of claim 5, wherein the micro-mirrors have a first stable state and a second stable state,

when the micro-reflector is in the first stable state, the proportion of first detection light emitted by the micro-reflector is 100%, and the proportion of 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%.

7. A spectrometer as in claim 6, wherein the receiving system comprises a first receiving subsystem to receive the first target light and decode the first target light based on the wavelength encoded data and a second receiving subsystem to receive the second target light and decode the second target light based on the verification data.

8. The spectrometer as claimed in claim 1, wherein the source light includes N light beams of a wavelength band to be measured, the control device generates a timing code data for each detection of the target to be measured, the modulation device modulates a time period of the source light into a modulation cycle according to the timing code data, the modulation cycle includes N modulation periods, and the modulation device is configured to modulate the light beams of the corresponding wavelength band to be measured with data in different data bits in the wavelength code data in different modulation periods.

9. The spectrometer of claim 8, wherein each modulation cycle comprises a plurality of modulation periods in one-to-one correspondence with a plurality of wavelength bands to be measured, and in each modulation cycle, the modulation device emits modulated sub-beams of different wavelength bands to be measured as the first detection light at different modulation periods.

10. The spectrometer of claim 8, wherein each modulation cycle comprises a plurality of modulation periods in one-to-one correspondence with a plurality of wavelength bands under test, and the modulation device increases or decreases the modulated sub-beam of one wavelength band under test in one modulation period in each modulation cycle to be emitted as the first detection light.

11. A spectrometer as in claim 1, wherein the light source comprises a light emitting unit and a dispersive component, wherein the light emitting unit is configured to generate a wide spectrum of light, the wide spectrum of light includes a plurality of light beams of different wavelength bands to be measured that overlap each other in space, and the wide spectrum of light passes through the dispersive component to obtain light source light in which the light beams of different wavelength bands to be measured are separated from each other in space.

12. A spectrometer as claimed in claim 11, wherein the dispersive element comprises a first diffractive element and a second diffractive element, the broad spectrum light passes through the first diffractive element and the second diffractive element in sequence to obtain a first order diffracted light and a second order diffracted light respectively, the first order diffracted light comprises a plurality of light beams of different wavelength bands spaced apart from each other along a first direction, one light beam of each wavelength band in the first order diffracted light is converted into a light beam of a part of the wavelength bands to be measured in the second order diffracted light, the part of the wavelength bands to be measured is spaced apart from each other along a second direction, the first direction is different from the second direction, and the second order diffracted light is used as the source light.

13. The spectrometer of claim 12, wherein the first diffractive element and the second diffractive element are both transmissive gratings.

14. The spectrometer of claim 12, wherein the first diffractive element is a reflective grating and the second diffractive element is a transmissive grating.

15. A spectrometer as claimed in any of claims 1 to 14 wherein the emission system further comprises an integrator, and the first detection light or the second detection light emitted from the modulator is used to illuminate the target after being homogenized by the integrator.

16. The spectrometer of any of claims 1-14, wherein the light source comprises an array of light emitters, each light emitter in the array of light emitters being configured to emit a light beam in a wavelength band of interest in the source light.

17. The spectrometer of claim 16, wherein the array of light emitters comprises an array of light emitting diodes or an array of laser diodes.

18. A spectrometer as claimed in any of claims 1 to 14 wherein the light source comprises an array of wavelength converting materials and a light emitting diode or laser diode, the array of wavelength converting materials comprising a plurality of wavelength converting elements of different materials arranged in an array, each wavelength converting element being adapted to generate a light beam of a wavelength band to be measured in the source light under excitation by light from the light emitting diode or laser diode.

19. The spectrometer of any of claims 1-14, wherein the source light is infrared light.