High-modulation integrated cellulose liquid crystal diffraction spectrum device and preparation method thereof, diffraction spectrum information sensing system and method

Abstract

The present application relates to a diffraction spectrum information sensing system and method, in particular to a high modulation integrated cellulose liquid crystal diffraction spectrum device and a preparation method thereof, a diffraction spectrum information sensing system and method, which solves the technical problems of narrow regulation band and low integration of the existing liquid crystal diffraction spectrum device. The high modulation integrated cellulose liquid crystal diffraction spectrum device uses the diffraction microstructure of the diffraction microzone in the cellulose liquid crystal diffraction layer to obtain the diffraction light field in the XY plane, and the diffraction spectrum information can be obtained by single imaging of the detector, avoiding the complex operation of the traditional diffraction spectrum device which expands the spectrum along the Z axis direction and the detector needs to be moved multiple times to obtain the diffraction spectrum information, without moving parts, higher integration and smaller size; meanwhile, the modulation layer can realize dynamic fine regulation of the diffraction spectrum, and the regulation band is wide. The diffraction spectrum information sensing system of the present application realizes the space-time modulation of the diffraction spectrum information through the control unit and the external modulator.

Description

TECHNICAL FIELD

[0001] The present application relates to a diffraction spectrum information sensing system and method, in particular to a high modulation integrated cellulose liquid crystal diffraction spectrum device and a preparation method thereof, a diffraction spectrum information sensing system and method. BACKGROUND

[0002] With the rapid development of the intelligent era, dynamic modulated spectrum information sensing technology has attracted widespread attention in the fields of smart medical care, smart agriculture, artificial intelligence vision system, etc. Liquid crystal, as a kind of intelligent material that dynamically responds to external electric field, magnetic field, thermal field, etc., has become an important material basis in the field of dynamic modulated spectrum information sensing technology.

[0003] The liquid crystal diffraction spectrum device expands the incident light along its transmission direction, which can realize high energy efficiency sensing and detection of spectral information, and meets the development needs of actual weak ambient spectrum information sensing technology. The liquid crystal diffraction spectrum device controls the spectral information by electric field, etc., so as to overcome the problem that the optical parameters of the traditional optical diffraction spectrum device are fixed and it is difficult to meet the development needs of intelligent reconfigurable spectrum information sensing technology. The commonly used liquid crystal diffraction spectrum device needs to be sealed in a liquid crystal cell structure, and it is very sensitive to the external temperature field, so that complex temperature control equipment is needed to realize accurate control of the spectral information. In addition, the preparation method of the liquid crystal diffraction spectrum device is usually a light orientation method on chip, and its cost rises rapidly with the increase of integration, which is difficult to meet the development needs of high-integration micro-diffraction spectrum information sensing technology.

[0004] At present, the cellulose liquid crystal diffraction spectrum device, as a new type of liquid crystal device that can maintain the liquid crystal director arrangement structure in solid state, does not need complex liquid crystal cell structure and temperature control equipment, and has become an important part of micro-diffraction spectrum information sensing technology. However, the existing cellulose liquid crystal diffraction spectrum device and its information sensing system usually adopt simple passive concentration modulation method and on-chip single diffraction structure modulation method. The passive concentration modulation method is described in yuanyuan Cao, et al, Adv. Mater. 2020. 32. 1907376, and the on-chip single diffraction structure modulation method is described in Guang Chu, et al, Adv. Optical Mater. 2021. 9. 2002258. Both methods have the problems of narrow modulation range and low integration, which are difficult to meet the development needs of high modulation micro-diffraction spectrum information sensing technology. Therefore, it is urgent to develop a wide-band, high-integration cellulose liquid crystal diffraction spectrum device and its spectrum information sensing system to meet the application scene needs of actual high-energy efficiency high-spectrum or even hyperspectrum technology. SUMMARY

[0005] The purpose of this invention is to solve the technical problems of narrow modulation band and low integration of existing liquid crystal diffraction spectroscopy devices, and to provide a highly modulated integrated cellulose liquid crystal diffraction spectroscopy device and its preparation method, as well as a diffraction spectroscopy information sensing system and method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-modulation integrated cellulose liquid crystal diffraction spectroscopy device, characterized in that it includes a modulation layer and a cellulose liquid crystal diffraction layer disposed on the modulation layer;

[0008] The cellulose liquid crystal diffraction layer is made of cellulose liquid crystal and includes N diffraction micro-regions, where N is an integer and N≥1;

[0009] The diffraction microstructure of the diffraction micro-region is a one-dimensional diffraction grating, a two-dimensional diffraction grating, or a random diffraction microstructure, used to receive the test laser and diffract it, so that the test laser produces a diffraction pattern in the XY plane; the XY plane is a plane perpendicular to the transmission optical path of the test laser.

[0010] The modulation layer is used to connect with an external modulator to modulate the spatial structure of the cellulose liquid crystal in the N diffraction micro-regions of the cellulose liquid crystal diffraction layer, thereby modulating the diffraction characteristics of the test laser corresponding to the N diffraction micro-regions.

[0011] Furthermore, N≥4, the N diffraction micro-regions are arranged in an array.

[0012] Furthermore, the maximum linewidth of the diffraction micro-region is 10 micrometers to 100 micrometers.

[0013] This invention also provides a method for fabricating the above-mentioned high-modulation integrated cellulose liquid crystal diffraction spectroscopy device, characterized by comprising the following steps:

[0014] Step A1: Preparation of high-pH region nematic cellulose liquid crystal: NaOH solution is added to cholesteric cellulose liquid crystal and then controlled to form a near-glassy nematic phase arrangement structure cellulose liquid crystal, thus obtaining a high-pH region nematic cellulose liquid crystal. Here, high pH refers to a pH value of 11.9-12.3.

[0015] Step A2: Preparation of a monolithic integrated PDMS diffraction master: Design a cellulose liquid crystal diffraction layer structure with N diffraction micro-regions and a diffraction microstructure with N diffraction micro-regions, and prepare a metal mask accordingly; then transfer the N diffraction microstructures on the metal mask to the SU8 master, combining them with the microstructure of the SU8 master itself to obtain the SU8 master with N composite microstructures; then imprint the N composite microstructures on the SU8 master onto the PDMS diffraction structure to obtain a monolithic integrated PDMS diffraction master with N composite diffraction microstructures;

[0016] Step A3: Preparation of integrated cellulose liquid crystal diffraction spectroscopy device: Select a conductive substrate, perform oxygen cleaning on the conductive surface of the conductive substrate, then drop high-pH nematic cellulose liquid crystal onto the conductive surface of the conductive substrate, and cover the high-pH nematic cellulose liquid crystal with a monolithic integrated PDMS diffraction master, so that the high-pH nematic cellulose liquid crystal has N composite diffraction microstructures on the monolithic integrated PDMS diffraction master. After drying, remove the monolithic integrated PDMS diffraction master to form a cellulose liquid crystal diffraction layer, and obtain the integrated cellulose liquid crystal diffraction spectroscopy device.

[0017] Step A4: Fabrication of a high-modulation integrated cellulose liquid crystal diffraction spectrometer: Apply conductive silver paste to the edge of each diffraction micro-region of the integrated cellulose liquid crystal diffraction spectrometer. The conductive silver paste and the conductive substrate together form a modulation layer, thus obtaining the high-modulation integrated cellulose liquid crystal diffraction spectrometer.

[0018] Further, in step A1, the volume ratio of NaOH solution to cholesteric cellulose liquid crystal is 0.22:1 to 0.24:1, wherein the concentration of NaOH solution is 2 mol / L.

[0019] Further, in step A2, the N diffraction microstructures on the metal mask are transferred to the SU8 master plate by ultraviolet spectroscopy, and the N composite microstructures on the SU8 master plate are imprinted onto the PDMS diffraction structure by soft photolithography.

[0020] In step A3, the conductive substrate is an indium tin oxide glass sheet or an indium tin oxide film.

[0021] The present invention also provides a diffraction spectral information sensing system, which is characterized in that it includes a light source module, a diffraction spectral device, a lens module, a detector and an external modulator;

[0022] The diffraction spectroscopy device is the aforementioned high-modulation integrated cellulose liquid crystal diffraction spectroscopy device;

[0023] The light source module includes N light source elements corresponding to N diffraction micro-regions of the cellulose liquid crystal diffraction layer in the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device, and a control circuit. Each light source element includes M semiconductor lasers with different emission colors for emitting test lasers, where M is an integer and M≥2. The control circuit is connected to the control terminals of the N×M semiconductor lasers to control the M semiconductor lasers in each light source element to work in a time-division manner, thereby emitting test lasers of different colors in a time-division manner.

[0024] The high-modulation integrated cellulose liquid crystal diffraction spectrometer is disposed in the transmission optical path of the test laser. The cellulose liquid crystal diffraction layer is used to receive N test laser beams, and the modulation layer is connected to an external modulator. The high-modulation integrated cellulose liquid crystal diffraction spectrometer is used to diffract the N test laser beams to generate diffraction patterns in the XY plane and transmit them to the object under test. At the same time, it works with the external modulator to modulate the diffraction characteristics of the N test laser beams.

[0025] The lens module and detector are sequentially arranged in the reflected light path of the object under test. The lens module includes N lens elements corresponding to N diffraction micro-regions of the cellulose liquid crystal diffraction layer in the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device, which are used to focus the reflected light of the object under test onto the detector. The detector includes N detector elements corresponding to the N lens elements, which are used to detect the diffraction spectral information carried by the reflected light of the object under test, thereby realizing the perception of diffraction spectral information.

[0026] Furthermore, the external modulator is an electric field modulator, a magnetic field modulator, or a mechanical field modulator.

[0027] Furthermore, M=3, and the M semiconductor lasers emit light in red, green, and blue colors, respectively.

[0028] This invention also provides a method for sensing diffraction spectral information, employing the aforementioned diffraction spectral information sensing system, characterized by the following steps:

[0029] Step B1: Turn on the external modulator, and then control one semiconductor laser of the N light source elements in the light source module to work through the control circuit, so that the N light source elements emit N test lasers and are respectively incident on the N diffraction micro-regions of the cellulose liquid crystal diffraction layer.

[0030] Step B2: Under the modulation of an external modulator, the modulation layer modulates the spatial structure of the cellulose liquid crystal in N diffraction micro-regions respectively. Then, the N diffraction micro-regions diffract the test laser emitted by their corresponding light source unit, so that the N test lasers generate diffraction patterns in the XY plane respectively and transmit them to the object under test.

[0031] Step B3: The lens module focuses the reflected light from the object under test onto the detector for detection, thereby obtaining the diffraction spectrum information of the object under test;

[0032] Step B4: Determine whether the diffraction spectrum information of the object under test meets the requirements for diffraction spectrum information perception. If yes, proceed to step B5; otherwise, change the output of the external modulator and return to step B2.

[0033] Step B5: Control another semiconductor laser in the N light source elements of the light source module to work through the control circuit, so that the N light source elements emit N test lasers and are respectively incident on the N diffraction micro-regions of the cellulose liquid crystal diffraction layer. Then return to step B2 until each semiconductor laser in the N light source elements of the light source module 1 is traversed to complete the perception of diffraction spectrum information.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The high-modulation integrated cellulose liquid crystal diffraction spectroscopy device provided by the present invention utilizes the diffraction microstructure of the diffraction micro-region of the cellulose liquid crystal diffraction layer to arrange the diffraction field of the test laser in the XY plane. The detector can obtain spectral information in a single imaging, avoiding the complex operation of traditional diffraction spectroscopy devices that expand the spectrum along the Z-axis (the transmission optical path of the test laser) and require the detector to move multiple times to obtain diffraction spectral information. It does not require high-precision mechanical moving parts and liquid lens control devices, and has higher integration and smaller size.

[0036] 2. The high-modulation integrated cellulose liquid crystal diffraction spectroscopy device provided by the present invention modulates the spatial structure of the cellulose liquid crystal by an external modulator, thereby achieving dynamic and precise control of the diffraction spectrum;

[0037] 3. The high-modulation integrated cellulose liquid crystal diffraction spectroscopy device provided by the present invention has a maximum linewidth of 10 micrometers to 100 micrometers in the diffraction micro-region, which can meet the energy requirements of the diffraction light field and reduce the manufacturing cost.

[0038] 4. The fabrication method of the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device provided by the present invention can be easily mass-produced by a single transfer forming process, avoiding the high cost caused by multiple transfers required by traditional electron beam lithography and photo-alignment technology, and breaking through the technical bottleneck of large-scale fabrication of array-type high-integration multi-diffraction micro-area liquid crystal devices.

[0039] 5. The diffraction spectral information sensing system provided by the present invention controls the light source element to emit test lasers of different colors in a time-division manner through the control unit, thereby achieving modulation of spectral information in the time domain. At the same time, the spatial structure of the cellulose liquid crystal in the high-modulation integrated cellulose liquid crystal diffraction spectral device is controlled by an external modulator, thereby modulating the diffraction characteristics of the test laser and achieving modulation of spectral information in the spatial domain. The modulation range is wide and the degree of freedom is high.

[0040] 6. The diffraction spectral information sensing system provided by this invention is compatible with mature imprinting, optical lens array and LD array technologies, and can be easily expanded in a planar array to realize large-area array modulation on the XY plane in the spatial domain. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device according to an embodiment of the present invention;

[0042] Figure 2 The following is a schematic diagram of the diffraction pattern of a one-dimensional diffraction grating in the diffraction microstructure of the diffraction micro-region in the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device of the present invention. Among them, (a), (b), (c), and (d) are schematic diagrams of diffraction patterns with periods of 10 micrometers, 20 micrometers, 40 micrometers, and 80 micrometers, respectively.

[0043] Figure 3 The following is a schematic diagram of the diffraction pattern of a two-dimensional diffraction grating in the diffraction microstructure of the diffraction micro-region in the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device of the present invention. Among them, (a) and (b) are schematic diagrams of the diffraction patterns of a two-dimensional square diffraction structure and a two-dimensional microbeam array diffraction structure, respectively.

[0044] Figure 4 This is a schematic diagram of the R (red) G (green) B (blue) three-color light diffraction pattern in the cellulose liquid crystal diffraction layer of the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device of the present invention using a one-dimensional diffraction grating. Among them, (a), (b), and (c) are schematic diagrams of the diffraction patterns of red, green, and blue light, respectively.

[0045] Figure 5 This is a schematic diagram of the structure of the diffraction spectrum information sensing system according to an embodiment of the present invention (external modulator not shown).

[0046] The annotations in the attached figures are explained as follows:

[0047] 1-Light source module, 2-High modulation integrated cellulose liquid crystal diffraction spectrometer, 21-Modulation layer, 22-Cellulose liquid crystal diffraction layer, 3-Object under test, 4-Lens module, 5-Detector. Detailed Implementation

[0048] To make the objectives, advantages, and features of the present invention clearer, the following describes in further detail, with reference to the accompanying drawings and specific embodiments, a high-modulation integrated cellulose liquid crystal diffraction spectroscopy device and its preparation method, as well as the diffraction spectroscopy information sensing system and method proposed in the present invention.

[0049] A high-modulation integrated cellulose liquid crystal diffraction spectroscopy device, such as Figure 1 As shown, the system includes a modulation layer 21 and a cellulose liquid crystal diffraction layer 22 disposed on the modulation layer 21. The cellulose liquid crystal diffraction layer 22 is made of cellulose liquid crystal and includes four diffraction micro-regions arranged in an array. The diffraction micro-regions are used to receive and diffract the test laser, causing the test laser to produce a diffraction pattern in the XY plane, where the XY plane is a plane perpendicular to the transmission path of the test laser. The modulation layer 21 is used to connect to an external modulator, thereby modulating the spatial structure of the cellulose liquid crystal in the four diffraction micro-regions of the cellulose liquid crystal diffraction layer 22, and thus modulating the diffraction characteristics of the test laser corresponding to each of the four diffraction micro-regions.

[0050] The maximum linewidth of the diffraction micro-region is 10 micrometers to 100 micrometers. 10 micrometers is the minimum linewidth for ultraviolet lithography, and 100 micrometers is the limiting linewidth for uniform arrangement of cellulose liquid crystals, which can avoid the high manufacturing cost of electron beam lithography.

[0051] The diffraction microstructure of the diffraction micro-regions can be a one-dimensional diffraction grating, a two-dimensional diffraction grating, or a random diffraction microstructure. The diffraction microstructures of the four diffraction micro-regions can be the same or different. The diffraction patterns of the one-dimensional and two-dimensional diffraction gratings in the diffraction micro-regions are as follows: Figure 2 , Figure 3 As shown, the diffraction patterns of the one-dimensional diffraction grating with periods of 10 μm, 20 μm, 40 μm, and 80 μm are as follows: Figure 2 As shown in (a), (b), (c), and (d), the diffraction patterns of the two-dimensional square diffraction structure and the two-dimensional microbeam array diffraction structure are as follows: Figure 3 As shown in (a) and (b), the diffraction patterns in the XY plane represent alternating bright and dark one-dimensional and two-dimensional spectra, respectively. Figure 4 As shown in (a), (b), and (c), these are schematic diagrams of the diffraction patterns of the diffraction microstructure in the diffraction micro-region, which are diffracted by a one-dimensional diffraction grating for RGB light.

[0052] This embodiment also provides a method for fabricating the above-mentioned high-modulation integrated cellulose liquid crystal diffraction spectroscopy device, including the following steps:

[0053] Step A1: Preparation of high-pH nematic cellulose liquid crystal: Add 22 to 24 μL of 2 mol / L NaOH solution (sodium hydroxide solution) to 1 mL of cholesteric cellulose liquid crystal, and then regulate it to form a near-glassy nematic phase arrangement structure of cellulose liquid crystal, thus obtaining a high-pH nematic cellulose liquid crystal. Here, high pH refers to a pH value of 11.9-12.3.

[0054] The near-glass nematic arrangement of cellulose liquid crystals has relatively small intermolecular interactions, enabling one-dimensional long-range ordered arrangement. At the same time, the near-glass structure can avoid the perturbation defects of liquid crystal molecules during subsequent integration.

[0055] Step A2: Preparation of a monolithically integrated PDMS (polydimethylsiloxane) diffraction master: Using optical design software, a cellulose liquid crystal diffraction layer structure with four diffraction micro-regions arranged in an array and a diffraction microstructure of the four diffraction micro-regions are designed, and a chromium mask is prepared accordingly; then, the four diffraction microstructures on the chromium mask are transferred to the SU8 master using ultraviolet spectroscopy, so that they are combined with the microstructure of the SU8 master itself, resulting in an SU8 master with four composite microstructures; then, the four composite microstructures on the SU8 master are imprinted onto the PDMS diffraction structure using soft photolithography, resulting in a monolithically integrated PDMS diffraction master with four composite diffraction microstructures.

[0056] Step A3: Preparation of integrated cellulose liquid crystal diffraction spectroscopy device: An indium tin oxide (ITO) glass sheet is selected as the conductive substrate. The conductive surface of the ITO glass sheet is oxygen-cleaned. Then, a high-pH region nematic cellulose liquid crystal is dropped onto the conductive surface of the ITO glass sheet. A monolithic integrated PDMS diffraction master is then placed on the high-pH region nematic cellulose liquid crystal, so that the high-pH region nematic cellulose liquid crystal has the four composite diffraction microstructures on the monolithic integrated PDMS diffraction master. After being placed in a drying oven for 24 hours, the monolithic integrated PDMS diffraction master is removed. The ITO glass sheet and the high-pH region nematic cellulose liquid crystal form a cellulose liquid crystal diffraction layer 22, thus obtaining the integrated cellulose liquid crystal diffraction spectroscopy device.

[0057] In other embodiments, the conductive substrate can also be an indium tin oxide thin film. This step enables the one-time fabrication of integrated devices, significantly reducing costs. The SU8 master template and PDMS diffraction structure themselves possess microstructures, which, when combined with nematic cellulose liquid crystals in the high pH region, can further optimize the diffraction effect.

[0058] Step A4: Fabrication of a high-modulation integrated cellulose liquid crystal diffraction spectrometer: A conductive silver paste is brushed onto the edge of each polarization micro-region of the integrated cellulose liquid crystal diffraction spectrometer. The conductive silver paste and the conductive substrate together form a modulation layer 21, resulting in a high-modulation integrated cellulose liquid crystal diffraction spectrometer 2.

[0059] In this step, an indium tin oxide glass sheet is bonded to conductive silver paste to form a modulation layer 21, which serves as a modulation medium connecting the external modulator and the cellulose liquid crystal diffraction layer 22.

[0060] This embodiment also provides a diffraction spectral information sensing system, such as Figure 5 As shown, the system includes a light source module 1, a diffraction spectroscopy device, a lens module 4, a detector 5, and an external modulator. The diffraction spectroscopy device is the aforementioned highly modulated integrated cellulose liquid crystal diffraction spectroscopy device 2. The light source module 1 includes four light source elements corresponding to the four diffraction micro-regions of the cellulose liquid crystal diffraction layer 22 in the highly modulated integrated cellulose liquid crystal diffraction spectroscopy device 2, and a control circuit. Each light source element includes three semiconductor lasers with different emission colors for emitting test lasers. In this embodiment, the emission colors of the three semiconductor lasers are red, green, and blue, respectively. The control circuit is connected to the control terminals of the 4×3 semiconductor lasers to control the three semiconductor lasers in each light source element to operate in a time-division manner, thereby emitting test lasers of different colors in a time-division manner.

[0061] The high-modulation integrated cellulose liquid crystal diffraction spectrometer 2 is disposed in the transmission optical path of the test laser. The cellulose liquid crystal diffraction layer 22 is used to receive four test laser beams, and the modulation layer 21 is connected to an external modulator. The high-modulation integrated cellulose liquid crystal diffraction spectrometer 2 is used to diffract the four test laser beams, so that they generate diffraction patterns in the XY plane respectively, and transmit them to the object under test 3. At the same time, it works with the external modulator to modulate the diffraction characteristics of the four test laser beams.

[0062] The external modulator is an electric field modulator, a magnetic field modulator, or a mechanical field modulator, which can directly modulate the spatial structure of the cellulose liquid crystal in the four diffraction micro-regions of the cellulose liquid crystal diffraction layer 22 in the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device 2, thereby realizing the fine control of diffraction spectral information.

[0063] Lens module 4 and detector 5 are sequentially arranged in the reflected light path of the object under test 3. Lens module 4 includes four lens elements corresponding to the four diffraction micro-regions of the cellulose liquid crystal diffraction layer 22 in the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device 2, used to focus the reflected light from the object under test onto detector 5. Detector 5 is an area array detector, including four detector elements corresponding to the four lens elements, used to detect the diffraction spectral information carried by the reflected light from the object under test 3, thereby realizing the perception of diffraction spectral information.

[0064] The diffraction microstructures of the four diffraction microregions in the cellulose liquid crystal diffraction layer 22 are small in size. In this embodiment, a laser is used as the test light. The spectral linewidth of the laser is extremely narrow, close to that of ideal monochromatic light, which can avoid the overlap of adjacent diffraction patterns in the diffraction pattern generated after diffraction and improve the spectral resolution.

[0065] In this embodiment, a test laser emitted from the light source module 1 is incident on the highly modulated integrated cellulose liquid crystal diffraction spectrometer 2. The test laser passes through four diffraction micro-regions of the cellulose liquid crystal diffraction layer 22, generating four diffraction patterns in the XY plane. The laser then strikes the object under test 3, and the reflected light carrying the spectral information of the object under test 3 is collected by the lens module 4. Finally, the detector 5 detects and senses the diffraction spectrum information of the object under test 3. Specifically, the control circuit controls the three semiconductor lasers of each light source element in the light source module 1 to emit RGB three-color test lasers in a time-division manner, achieving modulation in the time domain. An external modulator modulates the spatial structure of the cellulose liquid crystal in the four diffraction micro-regions of the cellulose liquid crystal diffraction layer 22, thereby modulating the diffraction characteristics of the test laser and causing it to diffract to different positions in the XY plane, achieving modulation in the spatial domain.

[0066] This embodiment also provides a method for sensing diffraction spectral information, which uses the above-mentioned diffraction spectral information sensing system and includes the following steps:

[0067] Step B1: Turn on the external modulator, and then control one of the semiconductor lasers of the four light source elements in the light source module 1 to work through the control circuit, so that the four light source elements emit four green test lasers that are respectively incident on the four diffraction micro-regions of the cellulose liquid crystal diffraction layer 22.

[0068] In step B2, the modulation layer 21 modulates the spatial structure of the cellulose liquid crystal in the four diffraction micro-regions under the modulation of the external modulator. Then, the N diffraction micro-regions diffract the green test laser emitted by their corresponding light source units, so that the four green test lasers generate diffraction patterns in the XY plane and are transmitted to the object under test 3.

[0069] Step B3: Lens module 4 focuses the reflected light from the object under test 3 onto detector 5 for detection, and obtains the diffraction spectrum information of the object under test 3 under the green test laser.

[0070] Step B4: Determine whether the diffraction spectrum information of the object under test 3 meets the requirements for diffraction spectrum information perception. If yes, proceed to step B5; otherwise, change the output of the external modulator and return to step B2.

[0071] Step B5: Control the other semiconductor laser of each of the four light source elements in the light source module 1 through the control circuit, so that the four light source elements emit four red and blue test lasers in sequence and are incident on the four diffraction micro-regions of the cellulose liquid crystal diffraction layer 22 respectively. Then, following the method of steps B2 to B4, obtain the diffraction spectrum information of the object under test 3 under green, red and blue test lasers, and complete the perception of diffraction spectrum information.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A method for preparing a high-modulation integrated cellulose liquid crystal diffraction spectrum device, the high-modulation integrated cellulose liquid crystal diffraction spectrum device comprising a modulation layer (21) and a cellulose liquid crystal diffraction layer (22) disposed on the modulation layer (21); N is an integer, and N≥1; The cellulose liquid crystal diffraction layer (22) is prepared from cellulose liquid crystal, and includes N diffraction micro-zones, wherein, the diffraction microstructure of the diffraction microregion is a one-dimensional diffraction grating, a two-dimensional diffraction grating, or a random diffraction microstructure, for receiving and diffracting a test laser, so that the test laser produces a diffraction pattern in an XY plane; the XY plane is a plane perpendicular to the transmission path of the test laser; the modulation layer (21) is used to be connected with an external modulator, so as to respectively modulate the spatial structure of the cellulose liquid crystal in the N diffraction microregions of the cellulose liquid crystal diffraction layer (22), and then respectively modulate the diffraction characteristics of the N diffraction microregions corresponding to the test laser; characterized in that it comprises the following steps: Step A1, preparing a high-pH nematic phase cellulose liquid crystal: adding a NaOH solution to a cholesteric phase cellulose liquid crystal, and then regulating it to form a near-glass nematic phase arrangement structure cellulose liquid crystal, to obtain a high-pH nematic phase cellulose liquid crystal, wherein the high pH refers to a pH value of 11.9-12.3, the volume ratio of the NaOH solution to the cholesteric phase cellulose liquid crystal is 0.22:1 to 0.24:1, and the concentration of the NaOH solution is 2 mol / L; Step A2, preparing a monolithic integrated PDMS diffraction master: designing a cellulose liquid crystal diffraction layer structure with N diffraction microregions and a diffraction microstructure of the N diffraction microregions, and preparing a metal mask plate according to the same; then transferring the N diffraction microstructures on the metal mask plate to a SU8 master, so that the N diffraction microstructures are combined with the microstructure of the SU8 master itself, to obtain a SU8 master with N composite microstructures; then imprinting the N composite microstructures on the SU8 master on a PDMS diffraction structure, to obtain a monolithic integrated PDMS diffraction master with N composite diffraction microstructures; Step A3, preparing an integrated cellulose liquid crystal diffraction spectrum device: selecting a conductive base layer, performing oxygen cleaning on the conductive surface of the conductive base layer, then adding the high-pH nematic phase cellulose liquid crystal to the conductive surface of the conductive base layer, and covering the monolithic integrated PDMS diffraction master on the high-pH nematic phase cellulose liquid crystal, so that the high-pH nematic phase cellulose liquid crystal has the N composite diffraction microstructures on the monolithic integrated PDMS diffraction master, after drying, removing the monolithic integrated PDMS diffraction master, forming a cellulose liquid crystal diffraction layer (22), and obtaining an integrated cellulose liquid crystal diffraction spectrum device; Step A4, preparing a high-modulation integrated cellulose liquid crystal diffraction spectrum device: brushing conductive silver paste on the edge of each diffraction microregion of the integrated cellulose liquid crystal diffraction spectrum device, and the conductive silver paste and the conductive base layer together form a modulation layer (21), to obtain a high-modulation integrated cellulose liquid crystal diffraction spectrum device (2). N≥4, and the N diffraction microregions are arranged in a surface array.

2. The method for fabricating the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device according to claim 1, characterized in that: The maximum line width of the diffraction microregion is 10 microns to 100 microns.

3. A method of fabricating a high modulation integrated cellulose liquid crystal diffractive spectral device according to claim 1 or 2, characterized in that: ​ 4. The method for fabricating the high-modulation integrated cellulose liquid crystal diffraction spectroscopy device according to claim 3, characterized in that: In step A2, the N diffraction microstructures on the metal mask are transferred to the SU8 master by UV spectrum technology, and the N complex microstructures on the SU8 master are imprinted on the PDMS diffraction structure by soft lithography technology; In step A3, the conductive base layer is an indium tin oxide glass sheet or an indium tin oxide film.

5. A diffractive spectral information perception system characterized by: The device comprises a light source module (1), a diffraction spectrum device, a lens module (4), a detector (5) and an external modulator. The diffraction spectrum device is the high-modulation integrated cellulose liquid crystal diffraction spectrum device (2) as claimed in any one of claims 1-4. The light source module (1) comprises N light source elements corresponding to the N diffraction microzones of the cellulose liquid crystal diffraction layer (22) in the high-modulation integrated cellulose liquid crystal diffraction spectrum device (2) respectively, and a control circuit; each light source element comprises M semiconductor lasers with different emitting colors, for emitting test laser, wherein M is an integer and M≥2; the control circuit is connected with the control ends of the N×M semiconductor lasers, for controlling the M semiconductor lasers in each light source element to work in time division, so that test laser with different colors is emitted in time division. The high-modulation integrated cellulose liquid crystal diffraction spectrum device (2) is arranged on the transmission light path of the test laser, the cellulose liquid crystal diffraction layer (22) is used for receiving the N test lasers, and the modulation layer (21) is connected with the external modulator; the high-modulation integrated cellulose liquid crystal diffraction spectrum device (2) is used for diffracting the N test lasers, so that the N test lasers respectively generate diffraction patterns in the XY plane and are transmitted to the object (3) to be detected, and the diffraction characteristics of the N test lasers are modulated in cooperation with the external modulator. The lens module (4) and the detector (5) are arranged on the reflection light path of the object (3) to be detected in sequence, the lens module (4) comprises N lens elements corresponding to the N diffraction microzones of the cellulose liquid crystal diffraction layer (22) in the high-modulation integrated cellulose liquid crystal diffraction spectrum device (2), for focusing the reflection light of the object (3) to be detected to the detector (5); the detector (5) comprises N detector elements corresponding to the N lens elements, for detecting the diffraction spectrum information carried by the reflection light of the object (3) to be detected, so as to realize the perception of the diffraction spectrum information.

6. The diffractive spectral information sensing system of claim 5, wherein: The external modulator is an electric field modulator, a magnetic field modulator or a mechanical field modulator.

7. The diffractive spectral information perception system of claim 6, wherein: M=3, and the emitting colors of the M semiconductor lasers are red, green and blue respectively.

8. A diffraction spectrum information sensing method using the diffraction spectrum information sensing system according to any one of claims 5 to 7, characterized by, The device comprises the following steps: In step B1, the external modulator is turned on, and then one semiconductor laser in each of the N light source elements in the light source module (1) is controlled to work by the control circuit, so that the N light source elements emit N test lasers respectively to the N diffraction microzones of the cellulose liquid crystal diffraction layer (22); In step B2, the spatial structure of the cellulose liquid crystal in each of the N diffraction microzones is modulated by the modulation layer (21) under the modulation of the external modulator, and then each of the N diffraction microzones diffracts the test laser emitted by the corresponding light source element, so that the N test lasers respectively generate diffraction patterns in the XY plane and are transmitted to the object (3) to be detected. Step B3, the lens module (4) focuses the reflected light of the object (3) to the detector (5) for detection, and the diffraction spectrum information of the object (3) is obtained; Step B4, judging whether the diffraction spectrum information of the object (3) meets the requirement of diffraction spectrum information sensing, if yes, executing step B5; if not, changing the output of the external modulator and returning to step B2; Step B5, controlling another semiconductor laser of the N light source units in the light source module (1) to work through the control circuit, so that the N light source units emit N test lasers respectively to the N diffraction micro areas of the cellulose liquid crystal diffraction layer (22), and then returning to step B2 until each semiconductor laser of the N light source units in the light source module (1) is traversed, and the sensing of the diffraction spectrum information is completed.

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