Miniature spectrometer system of transparent polymer material based on stress regulation and control

Abstract

The invention discloses a stress regulation-based micro spectrometer system of a transparent polymer material. The system comprises a polarization modulation unit, a transparent polymer layer, an imaging detector and a spectrum reconstruction module. The transparent polymer material is stretched by a specific design and then is arranged between the two polarizing films of the polarization modulation unit, and the imaging detector chip is arranged at the bottom layer of the device. And the spectrum reconstruction module performs spectrum reconstruction on the data received by the imaging detector by applying a calculation spectrum reconstruction algorithm to restore the original spectrum data received by the whole device. According to the technical scheme, a new spectrum detection thought is provided, and high-resolution spectrum analysis can be carried out in each wave band while the size of a miniature device is ensured by adjusting the applicable wave band of each component.

Description

Technical Field

[0001] The present invention relates to micro-spectrometer technology, and in particular to a micro-spectrometer system based on stress-regulated transparent polymer materials. The micro-spectrometer system is suitable for different wavelengths, such as visible light, near-infrared (NIR), short-wave infrared (SWIR), medium-wave infrared (MWIR) and long-wave infrared (LWIR), and can be widely used in spectral analysis, environmental monitoring, biomedical testing, industrial testing and other fields. Background Art

[0002] Spectral detection technology plays a key role in multiple fields. However, traditional spectral analysis systems rely on bulky and costly optical components such as gratings, prisms, and tunable filters, hindering device miniaturization and integration. Furthermore, existing computational spectral analysis techniques still have limitations in spectral resolution, imaging speed, and applicable wavelengths. A new, more compact, efficient, and multi-band spectral analysis solution is urgently needed.

[0003] The above content is only used to assist in understanding the technical solution of the present invention and does not constitute an admission that the above content is prior art. Summary of the Invention

[0004] This invention provides a micro-spectrometer system based on stress-controlled transparent polymer materials. By combining polarization modulation with a computational spectral reconstruction algorithm, it achieves a compact, high-spectral-resolution micro-spectrometer system. This system is applicable to multiple wavelengths and has broad applications in environmental monitoring, biomedical analysis, food safety testing, remote sensing, and other fields.

[0005] To achieve the above-mentioned object, the micro-spectrometer system proposed in the present invention includes a polarization modulation unit, a transparent polymer layer, an imaging detector and a spectrum reconstruction module;

[0006] The polarization modulation unit comprises at least a polarizer and an analyzer, which are used to perform polarization modulation and polarization analysis on the incident light respectively;

[0007] The transparent polymer layer is made of a transparent polymer material that has undergone stress regulation to have birefringence characteristics. It is arranged between the polarizer and the analyzer of the polarization modulation unit and modulates the incident light using the birefringence effect.

[0008] The imaging detector is used to receive the light signal modulated by the polarization modulation unit and the transparent polymer layer;

[0009] The spectrum reconstruction module uses a spectrum reconstruction algorithm to extract and reconstruct spectrum information from the light signal received by the imaging detector.

[0010] According to a preferred embodiment of the present invention, the polarizer and analyzer of the polarization modulation unit are polarizers suitable for polarization modulation of visible light, near-infrared light, short-wave infrared light, and long-wave infrared light. Preferably, the polarizer and analyzer are linear polarizers, circular polarizers, thin-film polarizers, or grating polarizers. Preferably, the polarization directions of the polarizer and analyzer are parallel or perpendicular to each other.

[0011] According to a preferred embodiment of the present invention, the stress regulation treatment method of the transparent polymer layer includes the following steps: heating the transparent polymer material, applying internal stress to the transparent polymer material by mechanical stretching, cooling the material while maintaining the stretched state, fixing the internal stress in the material, and obtaining a transparent polymer layer, wherein different stretching ratios will produce different birefringence coefficients, thereby modulating the incident light.

[0012] According to a preferred embodiment of the present invention, the transparent polymer material is epoxy resin, PMMA (polymethyl methacrylate), PET (polyethylene terephthalate), PS (polystyrene) or PC (polycarbonate), and the area of the transparent polymer layer covers the entire imaging detector.

[0013] The imaging detector includes but is not limited to complementary metal oxide semiconductor (CMOS), charge coupled device (CCD), indium gallium arsenide (InGaAs) detector, mercury cadmium telluride (HgCdTe) detector or other photodetectors suitable for different bands, which are used to receive the modulated optical signal.

[0014] The spectral reconstruction algorithm used by the spectral reconstruction module includes but is not limited to traditional regularization algorithm (Regularization), compressed sensing (Compressed Sensing), neural network (Neural Networks), deep learning (Deep Learning), etc., which are used to extract and reconstruct spectral information from the detector signal.

[0015] The present invention also provides a spectrum analysis method based on the micro-spectrometer system, which comprises the following steps:

[0016] 1) selecting a polarizer, an analyzer, and an imaging detector suitable for the wavelength of the incident light to be detected according to the wavelength band of the incident light to be detected, obtaining a required birefringence of the transparent polymer layer according to the wavelength band of the incident light to be detected, setting a stretch ratio of the transparent polymer material according to the required birefringence, then processing the transparent polymer layer, and assembling the obtained components into the micro-spectrometer system;

[0017] 2) After the incident light to be detected passes through the polarizer, it is decomposed into two orthogonal polarization components, namely the ordinary light polarization component and the extraordinary light polarization component. The two components correspond to the ordinary light refractive index n of the transparent polymer layer. o and the extraordinary refractive index n e Since the two components have different refractive indices in the transparent polymer layer, their propagation speeds in the transparent polymer layer are also different, resulting in a phase difference and causing light dispersion.

[0018] The phase difference Δφ between ordinary and extraordinary light oe Expressed as:

[0019]

[0020] Among them, |n o -n e | is the birefringence coefficient of the transparent polymer material, λ is the wavelength of the incident light, and d is the thickness of the birefringent material. After being screened by the analyzer, the intensity I of the transmitted light is expressed as:

[0021]

[0022] Where I0 is the intensity of the incident light, α and β are the polarization axis angles of the polarizer and analyzer respectively;

[0023] 3) The imaging detector receives the modulated light information and reads it out as a digital or analog signal. The spectral reconstruction module then uses a spectral reconstruction algorithm to analyze the modulated light signal and reconstruct the pre-modulation spectral information to achieve multi-band spectral analysis.

[0024] The present invention uses the birefringence effect of transparent polymer materials to encode spectral information. The birefringence coefficient of transparent polymer materials is zero when unstretched and gradually increases with the stretch ratio. Therefore, the birefringence coefficient of transparent polymer materials can be controlled according to the stretch ratio. By optimizing the mechanical stretching parameters of the transparent polymer material and combining it with a polarizer, the present invention achieves multi-band spectral detection and combines it with advanced computational spectroscopy methods to improve spectral resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0026] Figure 1 This is a structural diagram of an example perspective of the micro-spectrometer system of the present invention;

[0027] Figure 2 Schematic diagram of the stretching of the stress-regulated transparent polymer material of the present invention;

[0028] Figure 3 This is the internal stress change curve of a transparent polymer material (taking epoxy resin E-51 as an example) after stretching;

[0029] Figure 4 This is a schematic diagram of the birefringence principle of the transparent polymer material of the present invention;

[0030] Figure 5 The transmittance spectra of transparent polymer materials (taking epoxy resin E-51 as an example) at different positions along the stretching direction under polarized dark field;

[0031] Description of the accompanying drawings: 10 - polarization modulation unit, 11 - natural light, 12 - polarizer, 13 - transparent polymer layer, 14 - analyzer, 15 - detector.

[0032] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0035] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] The present invention provides a micro-spectrometer system based on a stress-regulated transparent polymer material.

[0037] Reference Figure 1 In one embodiment of the present invention, the physical structure of the micro-spectrometer system includes:

[0038] The polarization modulation unit 10 (including a polarizer 12 and an analyzer 14 ), a transparent polymer layer 13 and an imaging detector 15 .

[0039] Reference Figure 1 The structure of the spectral imaging system from top to bottom is: a polarizer 12, a transparent polymer layer 13, an analyzer 14 and an imaging detector 15.

[0040] The polarization directions of the polarizer 12 and the analyzer 14 should form a certain angle to obtain better wavelength selection characteristics. Preferably, the polarization directions of the polarizer 12 and the analyzer 14 are parallel or perpendicular to each other. The polarization modulation unit 10 includes but is not limited to linear polarizers, circular polarizers, thin film polarizers, grating polarizers, and other polarization modulation schemes suitable for various wavelength bands.

[0041] The transparent polymer layer 13 is based on the principle of birefringence and should have different optical refractive indices for ordinary light and extraordinary light after being stretched in a specially designed manner. o and n eIndicates. The transparent polymer material can be selected from transparent materials available on the market, such as epoxy resin, PMMA, PET, PS or PC, and the area of the transparent polymer layer covers the entire imaging detector. In a specific embodiment of the present invention, the stress regulation treatment method includes the following steps: heating the transparent polymer material (the heating temperature depends on the specific material, and the heated material should be easy to stretch), and applying internal stress to the transparent polymer material by mechanical stretching (using a certain tensile force to stretch the two opposite ends of the material to stretch the material to a set stretching ratio), cooling the material while maintaining the stretching state to solidify it, fixing the internal stress in the material, and obtaining a transparent polymer layer, wherein different stretching ratios will produce different birefringence coefficients, thereby modulating the incident light. Reference Figure 2 Figure 2 shows the principle of stress regulation in the present invention. Mechanical stretching generates different stresses within the material depending on its shape. In the unstretched state, the polymer chains are randomly curled and have no internal stress. Heating the material above its glass transition temperature and then stretching it causes the polymer chains to stretch, forming a directional structure that generates internal stress. After stretching, the material is cooled, and the internal stress is fixed.

[0042] The present invention takes the stretching of a thin plate-shaped isosceles triangle epoxy resin material (epoxy resin E-51) as an example, and the stretching direction is the axis direction of its symmetry axis. Figure 3 The figure shows the internal stress changes along the central axis of the stretched triangular epoxy resin material (black dashed arrow). The clamping part is the black area and is not stretched during the stretching process.

[0043] The spectrum analysis method using the micro-spectrometer system of the present invention comprises the following steps:

[0044] S1: According to the incident light to be detected (refer to Figure 4 In this embodiment, the incident light is natural light 11), and a polarizer, analyzer, and imaging detector suitable for the wavelength are selected. The birefringence required for the transparent polymer layer is obtained according to the wavelength band of the incident light to be detected. The stretching ratio of the transparent polymer material is set according to the required birefringence, and then the transparent polymer layer is processed to obtain the transparent polymer layer. The obtained components are assembled into the micro-spectrometer system.

[0045] S2: Reference Figure 4 When natural light 11 passes through the polarizer 12, it is decomposed into two orthogonal polarization components, namely the ordinary light polarization component and the extraordinary light polarization component. The two components correspond to the ordinary light refractive index n of the material. o and the extraordinary refractive index n eSince the two components have different refractive indices in the transparent polymer material, their propagation speeds are also different, resulting in a phase difference and causing light dispersion.

[0046] Mathematically, the phase difference Δφ between ordinary light and extraordinary light oe It can be expressed as:

[0047]

[0048] Among them, |n o -n e | is the birefringence coefficient of the transparent polymer layer 13, λ is the wavelength of the incident light, and d is the thickness of the birefringent material 13. After being screened by the analyzer 14, the intensity I of the transmitted light can be expressed as:

[0049]

[0050] Wherein, I0 is the intensity of the incident light, and α and β are the polarization axis angles of the polarizer 12 and the analyzer 14, respectively.

[0051] Here, an orthogonal polarization system is taken as an example, that is, the polarization axes of the polarizer 12 and the analyzer 14 are perpendicular to each other, β = α + π / 2, and the intensity of the transmitted light is:

[0052]

[0053] For natural light containing multiple wavelengths, the total intensity of the transmitted light is the sum of the intensities of all the monochromatic lights:

[0054]

[0055] Where i represents the light components of different wavelengths, (I0) i is the initial intensity of light at each wavelength.

[0056] For monochromatic light, the maximum transmission wavelength is determined by the following formula:

[0057]

[0058] Here, m is an integer.

[0059] Figure 5 Taking the aforementioned triangular epoxy resin material as an example, the transmission spectrum after modulation is shown. The stretching ratio of the material decreases from top to bottom, and the birefringence |n o -n e The larger the birefringence, the greater the fluctuations in the modulated transmission spectrum, and the richer the information contained. By gradually modulating the birefringence of the material, making it larger or smaller, the transmission spectrum information can be made to cover the entire operating wavelength range.

[0060] S3: The imaging detector 15 receives the light information modulated by the pre-structure and reads it out in the form of a digital or analog signal. The imaging detector includes but is not limited to complementary metal oxide semiconductor (CMOS), charge coupled device (CCD), indium gallium arsenide (InGaAs) detector, mercury cadmium telluride (HgCdTe) detector or other photoelectric detectors suitable for different bands, which are used to receive the modulated light signal. The modulated light signal is then analyzed using a spectral reconstruction algorithm to reconstruct the spectral information before modulation to achieve multi-band spectral analysis. The spectral reconstruction algorithm includes but is not limited to traditional regularization algorithm (Regularization), compressed sensing (Compressed Sensing), neural network (Neural Networks), deep learning (Deep Learning), etc.

[0061] It should be noted that the basic process of spectral analysis based on a micro-spectrometer and the spectral reconstruction algorithm involved in this process are well known in the art. The present invention does not require or limit the spectral reconstruction algorithm. Any spectral reconstruction algorithm applicable to spectral analysis in other micro-spectrometers is applicable to the micro-spectrometer of the present invention. The core innovation of this invention lies in encoding spectral information through the birefringence effect of a transparent polymer material. By optimizing the mechanical stretching parameters of the transparent polymer material and combining it with a polarizer, multi-band spectral detection is achieved.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A micro-spectrometer system based on stress-regulated transparent polymer materials, characterized in that: It includes a polarization modulation unit, a transparent polymer layer, an imaging detector and a spectrum reconstruction module; The polarization modulation unit comprises at least a polarizer and an analyzer, which are used to perform polarization modulation and polarization analysis on the incident light respectively; The transparent polymer layer is made of a transparent polymer material that has undergone stress regulation to have birefringence characteristics. It is arranged between the polarizer and the analyzer of the polarization modulation unit and modulates the incident light using the birefringence effect. The imaging detector is used to receive the light signal modulated by the polarization modulation unit and the transparent polymer layer; The spectrum reconstruction module uses a spectrum reconstruction algorithm to extract and reconstruct spectrum information from the light signal received by the imaging detector.

2. The micro-spectrometer system according to claim 1, wherein: The polarizer and analyzer of the polarization modulation unit are polarizers suitable for polarization modulation of visible light, near infrared light, short-wave infrared light and long-wave infrared light.

3. The micro-spectrometer system according to claim 1, wherein: The polarizer and analyzer are linear polarizers, circular polarizers, thin film polarizers or grating polarizers.

4. The micro-spectrometer system according to claim 1, wherein: The polarization directions of the polarizer and the analyzer are parallel or perpendicular to each other.

5. The micro-spectrometer system according to claim 1, wherein: The stress regulation treatment method for the transparent polymer layer includes the following steps: heating the transparent polymer material, applying internal stress to the transparent polymer material by mechanical stretching, cooling the material while maintaining the stretching state, fixing the internal stress in the material, and obtaining a transparent polymer layer, wherein different stretching ratios will produce different birefringence coefficients, thereby modulating the incident light.

6. The micro-spectrometer system according to claim 5, wherein: The transparent polymer material is epoxy resin, PMMA, PET, PS or PC, and the area of the transparent polymer layer covers the entire imaging detector.

7. The micro-spectrometer system according to claim 1, wherein: The imaging detector is a complementary metal oxide semiconductor, a charge coupled device, an indium gallium arsenide detector or a mercury cadmium telluride detector, and is used to receive the modulated light signal.

8. The micro-spectrometer system according to claim 1, wherein: The spectrum reconstruction algorithm adopted by the spectrum reconstruction module includes but is not limited to a traditional regularization algorithm, a compressed sensing algorithm, a neural network algorithm or a deep learning algorithm.

9. A spectrum analysis method based on the micro-spectrometer system according to any one of claims 1 to 8, characterized in that The steps include: 1) selecting a polarizer, an analyzer, and an imaging detector suitable for the wavelength of the incident light to be detected according to the wavelength band of the incident light to be detected, obtaining a required birefringence of the transparent polymer layer according to the wavelength band of the incident light to be detected, setting a stretch ratio of the transparent polymer material according to the required birefringence, then processing the transparent polymer layer, and assembling the obtained components into the micro-spectrometer system; 2) After the incident light to be detected passes through the polarizer, it is decomposed into two orthogonal polarization components, namely the ordinary light polarization component and the extraordinary light polarization component. The two components correspond to the ordinary light refractive index n of the transparent polymer layer. o and the extraordinary refractive index n e Since the two components have different refractive indices in the transparent polymer layer, their propagation speeds in the transparent polymer layer are also different, resulting in a phase difference and causing light dispersion. The phase difference Δφ between ordinary and extraordinary light oe Expressed as: Among them, |n o -n e | is the birefringence coefficient of the transparent polymer material, λ is the wavelength of the incident light, and d is the thickness of the birefringent material. After being screened by the analyzer, the intensity I of the transmitted light is expressed as: Where I0 is the intensity of the incident light, α and β are the polarization axis angles of the polarizer and analyzer respectively; 3) The imaging detector receives the modulated light information and reads it out as a digital or analog signal. The spectral reconstruction module then uses a spectral reconstruction algorithm to analyze the modulated light signal and reconstruct the pre-modulation spectral information to achieve multi-band spectral analysis.

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