Orthogonal grating polarization de-noising scanning type spectrum detection chip and application thereof

Abstract

The invention discloses a scanning type spectrum detection chip for orthogonal grating polarization denoising and an application of the scanning type spectrum detection chip. The detection chip comprises a bearing mechanism which can rotate around a rotating shaft and is at least used for performing angle scanning relative to the direction of incident light; the two spectrum detection units are arranged on the surface of the bearing mechanism in a spaced mode, each spectrum detection unit comprises a detector and an angle-sensitive one-dimensional grating structure, the one-dimensional grating structures are arranged on the detectors, and the detectors and the one-dimensional grating structures contained in the two spectrum detection units are the same; and the grating orientations of the one-dimensional grating structures contained in the two spectrum detection units are orthogonal. According to the detection chip, the high response contrast of the angle-sensitive one-dimensional grating structure to different polarized light is utilized, real-time signal difference is carried out through the completely same spectrum detection units integrated by the two orthogonal gratings in the scanning test process, noise can be effectively restrained, the signal-to-noise ratio is greatly increased, and the detection precision is improved. And the spectrum detection precision is obviously improved.

Description

Technical Field

[0001] The present application relates to a spectral detection chip, in particular to a scanning spectral detection chip with orthogonal grating polarization denoising and its application in spectral analysis, belonging to the technical field of optoelectronic devices. Background Art

[0002] At present, to meet the needs of various on-site rapid detections and spectral detections on light-load platforms, the industry has paid more and more attention to the research of micro-spectrometers. However, due to volume limitations, the detection performance of existing micro-spectrometers is inferior to that of bench-top spectrometers, and the anti-interference ability is weak. Tunable micro-spectrometers can achieve scanning spectral information sampling based on the technical architecture of a single detector combined with a tuning unit, and are expected to realize spectral detection chips with extremely low costs. However, their dynamically tunable working mode results in weaker anti-interference ability, seriously limiting the accuracy of spectral detection. Summary of the Invention

[0003] The main purpose of the present application is to provide a scanning spectral detection chip with orthogonal grating polarization denoising and its application, so as to overcome the deficiencies of the prior art.

[0004] To achieve the foregoing invention purpose, the technical solutions adopted in the present application include:

[0005] In a first aspect of the present application, there is provided a scanning spectral detection chip with orthogonal grating polarization denoising, which includes:

[0006] A carrying mechanism that can rotate around a rotation axis and is at least used for angular scanning relative to the incident light direction;

[0007] Two spectral detection units spaced apart on the surface of the carrying mechanism, each spectral detection unit includes a detector and an angle-sensitive one-dimensional grating structure, the one-dimensional grating structure is arranged on the detector, the materials and structures of the detectors and one-dimensional grating structures included in the two spectral detection units are the same, and the grating orientation of the one-dimensional grating structure included in one spectral detection unit is orthogonal to the grating orientation of the one-dimensional grating structure included in the other spectral detection unit.

[0008] Further, the two spectral detection units are respectively used as a working unit and a denoising unit. The grating orientation of the one-dimensional grating structure in the working unit is parallel to the rotation axis, and the polarization direction of the incident light is perpendicular to the rotation axis. That is to say, the grating of the working unit is parallel to the rotation axis, and the polarization direction of the incident light is perpendicular to the grating therein, which can excite resonance. The grating of the denoising unit is perpendicular to the rotation axis, and the polarization direction of the incident light is in the same plane as the grating therein, and resonance cannot be excited, showing a high reflection state.

[0009] Therefore, the difference between the working unit and the noise reduction unit lies in that the grating contained in the working unit can resonate with the incident light, and thus a photocurrent formed by resonance absorption or transmission will be generated. However, the grating contained in the noise reduction unit cannot resonate with the incident light, and thus a photocurrent formed by resonance absorption or transmission will not be generated.

[0010] In the present application, the angle-sensitive one-dimensional grating structure transmits or absorbs light of different wavelengths at different incident angles.

[0011] In one embodiment, the incident light is linearly polarized light. Relative to the one-dimensional grating structure (defined as the first grating structure) in one of the spectral detection units, the polarization direction of the incident light is parallel to the incident plane and perpendicular to the first grating structure, and it can be resonantly absorbed by the first grating structure (such as the Au-Si Schottky junction structure) or transmitted through the first grating structure and enter the corresponding detector (such as the InGaAs detector), and thus a photocurrent is generated. Relative to the one-dimensional grating structure (defined as the second grating structure) in the other spectral detection unit, the polarization direction of the incident light is perpendicular to the incident plane and parallel to the second grating structure, and it cannot be resonantly absorbed by the second grating structure or transmitted through the second grating structure and presents a high reflection state, so that a photocurrent cannot be generated thereby.

[0012] In one embodiment, the detector includes a photodetector or a photothermal detector. In some cases, the detector can also be other detectors capable of performing photoelectric conversion.

[0013] Furthermore, the detector can be directly formed by using the substrate. For example, the Si substrate material can be used as the photoelectric response material of the detector, and a metal-Si Schottky detector can be directly formed by processing it using silicon technology. Or, a photoelectric response material can be introduced by transfer, bonding or epitaxial growth on the substrate surface, and then a detector (such as graphene, Ge, etc.) can be prepared on the substrate by using semiconductor device technology. The substrate can be a part of the active region of the detector or only used as a substrate. Or, the substrate can be used as the carrier mechanism, and the already independently fabricated detector (such as InGaAs, Si, HgTe, etc. detectors) can be mounted on the substrate by means of patching, etc. The substrate and the detector are independent of each other and can be connected to each other through conductive lines, etc.

[0014] In one embodiment, the one-dimensional grating structure in the spectral detection unit can be integrally arranged on the detector.

[0015] Furthermore, the one-dimensional grating structure can be a part of the corresponding detector or integrated above the corresponding detector. In some cases, the detector can be integrally arranged with the one-dimensional grating structure.

[0016] Exemplarily, the detector in the spectral detection unit includes a semiconductor material, and a one-dimensional semiconductor grating is integrally formed on the surface of the semiconductor material. The one-dimensional grating structure includes the one-dimensional semiconductor grating and a metal material coated on the one-dimensional semiconductor grating, and a Schottky contact is formed between the metal material and the one-dimensional semiconductor grating.

[0017] Further, the semiconductor material may be selected from, but not limited to, III-V group semiconductor materials such as GaN and InGaAs, or other semiconductor materials such as crystalline silicon.

[0018] Exemplarily, the one-dimensional grating structure includes a one-dimensional dielectric grating disposed on the detector and a metal material coated on the one-dimensional dielectric grating, and the one-dimensional dielectric grating is formed of a dielectric material.

[0019] Further, the dielectric material may be selected from, but not limited to, inorganic dielectric materials or organic dielectric materials such as silicon dioxide, silicon nitride, aluminum oxide, hafnium oxide, magnesium fluoride, or polymethyl methacrylate.

[0020] Further, the thickness of the metal material coated on the one-dimensional semiconductor grating or the one-dimensional dielectric grating is greater than 20 nm and less than 100 nm.

[0021] Further, the metal material may be selected from, but not limited to, metals such as gold, platinum, silver, copper, aluminum, or titanium, or their alloys.

[0022] In the present application, the surface of the carrier mechanism is preferably a plane. Further, the distance between the two spectral detection units should preferably be as close as possible while ensuring non-contact, so as to minimize the influence of the incident light distribution. For example, the distance between the two spectral detection units can be controlled to be 5 μm to 2 mm.

[0023] More preferably, the two spectral detection units are symmetrically disposed on the surface of the carrier mechanism.

[0024] In one embodiment, the detection chip includes a substrate, and the substrate includes a fixed portion, a rotatable portion, and a rotation axis. The rotatable portion is the carrier mechanism and is rotatably mounted on the fixed portion through the rotation axis.

[0025] Exemplarily, the fixed portion has a frame structure, and the rotatable portion is rotatably mounted within the frame structure through the rotation axis.

[0026] Further, the material of the substrate may be selected from silicon or silicon on insulator (SOI), etc., and is not limited thereto. Exemplarily, the substrate may be a device that rotates about an axis fabricated on silicon or SOI based on MEMS technology, such as a silicon micro-mirror.

[0027] In one embodiment, the spectral detection unit has a first working electrode and a second working electrode. The first working electrode and the second working electrode are electrically connected to a first contact electrode and a second contact electrode respectively through a first electrode wiring and a second electrode wiring. Both the first electrode wiring and the second electrode wiring extend from the rotatable part to the fixed part along the rotation axis, and the first contact electrode and the second contact electrode are respectively arranged on the fixed part.

[0028] Further, the first working electrodes of the two spectral detection units can be connected to each other to form a common electrode, and the common electrode is electrically connected to a first contact electrode through a first electrode wiring. By adopting this design, the internal structure of the integrated chip can be made more concise and the manufacturing difficulty can be lower.

[0029] The second aspect of the present application provides a spectral detection method, which is implemented based on the above-mentioned scanning spectral detection chip, and the method includes:

[0030] Making the light to be detected incident on the scanning spectral detection chip;

[0031] Making the carrying mechanism rotate relative to the incident light to change the incident angle;

[0032] Recording and analyzing the corresponding detection signals output by the scanning spectral detection chip at each rotation angle of the carrying mechanism to realize the spectral detection of the light to be detected.

[0033] In one embodiment, the method specifically includes:

[0034] Defining two spectral detection units as a working unit and a noise reduction unit respectively, where the one-dimensional grating structure contained in the working unit can resonate with the incident light and generate a photocurrent signal formed by resonance absorption or transmission, and the one-dimensional grating structure contained in the noise reduction unit cannot resonate with the incident light and will not generate a photocurrent signal formed by resonance absorption or transmission;

[0035] Subtracting the photocurrent signal output by the working unit from the photocurrent signal output by the noise reduction unit to realize the noise reduction of the photocurrent signal output by the working unit, and then analyzing the spectrum of the light to be detected.

[0036] Compared with the prior art, the scanning spectral detection chip of the present application utilizes the high response contrast of the angle-sensitive one-dimensional grating structure to different polarized lights, and performs real-time signal difference through two completely identical spectral detection units integrated with orthogonal gratings during the scanning test process, which can effectively suppress noise, greatly improve the signal-to-noise ratio, and significantly improve the spectral detection accuracy. Description of the Drawings

[0037] Figure 1 It is a schematic structural diagram of a scanning spectroscopic detection chip in a typical embodiment of the present application;

[0038] Figure 2 It is a schematic structural diagram of the integration of a one-dimensional grating structure and a detector in a typical embodiment of the present application;

[0039] Figure 3 It is a schematic structural diagram of another integration of a one-dimensional grating structure and a detector in a typical embodiment of the present application;

[0040] Figure 4 It is a schematic structural diagram of yet another integration of a one-dimensional grating structure and a detector in a typical embodiment of the present application;

[0041] Figure 5 It is a top view of the one-dimensional grating structure in a typical embodiment of the present application;

[0042] Figure 6 It is a spectroscopic detection signal diagram formed by the response of the spectroscopic detection unit as a working unit to the light to be measured at different incident angles in a typical embodiment of the present application;

[0043] Figure 7 It is a spectroscopic detection signal diagram formed by the response of the spectroscopic detection unit as a denoising unit to the light to be measured at different incident angles in a typical embodiment of the present application;

[0044] Figure 8 It is a low-noise spectroscopic detection signal diagram obtained by performing differential processing on the spectroscopic detection signals of the working unit and the denoising unit in a typical embodiment of the present application;

[0045] Figure 9 It is a spectroscopic test diagram of non-differential denoising in a typical embodiment of the present application;

[0046] Figure 10 It is a spectroscopic test diagram of differential denoising in a typical embodiment of the present application;

[0047] Figure 11 It is a response spectroscopic diagram at different incident angles when p-polarized narrowband light and s-polarized broadband light with different central wavelengths in Example 1 are incident on a one-dimensional grating structure;

[0048] Figure 12 It is a spectroscopic detection signal diagram obtained by the response of the denoising unit, the working unit, and the reference device to the narrowband p-polarized incident light with the central wavelength λ1 at different incident angles and different denoising methods in Example 1. Specific embodiments

[0049] Currently, in the industry, micro or chip-type spectrometers are mainly used for on-site rapid spectral detection or spectral detection based on light-load platforms. However, most of the existing micro or chip-type spectrometers have the problem of low signal-to-noise ratio. For the scanning working mode, the influence of such environmental interference and system instability on the detection performance is more serious. In view of these deficiencies in the prior art, through long-term research and a large number of practices, the inventor of this case has proposed the technical solution of this application. It mainly utilizes the high response contrast of the angle-sensitive one-dimensional grating structure to different polarized lights, and performs real-time signal differential through two completely identical units integrated with orthogonal gratings during the scanning test process, that is, first differentiating the photocurrent, and then performing spectral analysis based on the differential signals at all angles, thereby effectively suppressing noise, significantly improving the signal-to-noise ratio, and greatly improving the spectral detection accuracy.

[0050] The technical solution of this application, its implementation process, principle, etc. will be further described below.

[0051] Please refer to Figures 1 - 5 As shown, in a typical implementation of this application, a scanning spectral detection chip includes a substrate 1 and two spectral detection units. Each spectral detection unit mainly consists of a detector and an angle-sensitive one-dimensional grating structure. The substrate 1 has a rotatable part 11, and the two spectral detection units are arranged on the surface of the rotatable part, and the rotatable part can rotate around a rotation axis 13 for angular scanning relative to the incident light direction.

[0052] If the two spectral detection units are respectively named the first spectral detection unit and the second spectral detection unit. Then the first spectral detection unit includes a first detector 21 and a first one-dimensional grating structure 31. The second spectral detection unit includes a second detector 22 and a second one-dimensional grating structure 32. The first detector 21 and the second detector 22 are identical detectors, that is, their materials, structures, etc. are all the same. At the same time, the materials and materials of the first one-dimensional grating structure 31 and the second one-dimensional grating structure 32 are also the same. The only difference is that the grating orientations of the two are orthogonal. If the first spectral detection unit is the working unit and the second spectral detection unit is the noise reduction unit, then the grating orientation of the one-dimensional grating structure in the working unit is parallel to the aforementioned rotation axis, and the grating orientation of the one-dimensional grating structure in the noise reduction unit is perpendicular to the aforementioned rotation axis.

[0053] Furthermore, in a spectral detection unit, the one-dimensional grating structure can be integrally arranged on the corresponding detector. Taking the first spectral detection unit as an example, please refer to Figure 2, in the first case, the first one-dimensional grating structure 31 is integrated on the first detector 21. The first one-dimensional grating structure 31 can be formed of metal and / or dielectric materials, and the incident light is absorbed by the first detector 21 after passing through the first one-dimensional grating structure 31. The material of the first one-dimensional grating structure 31 includes metals such as gold, platinum, silver, copper, aluminum, or titanium, and inorganic non-metallic materials or organic materials such as graphene, titanium nitride, zirconium nitride, indium tin oxide, zinc oxide, silicon dioxide, silicon nitride, aluminum oxide, hafnium oxide, magnesium fluoride, or polymethyl methacrylate.

[0054] In the second case, the first one-dimensional grating structure 31 can also form a part of the first detector 21, as Figure 3 shown, where 211 is a semiconductor material and 311 is a metal material. The first detector 21 is mainly formed of the semiconductor material 211, and a one-dimensional semiconductor grating is formed on its surface by physical / chemical etching or machining. The metal material 311 covers the one-dimensional semiconductor grating, and a Schottky detector is formed by metal-semiconductor contact. At the same time, the first one-dimensional grating structure 31 has an angle-sensitive characteristic, so that only the light energy with the corresponding wavelength can be selectively absorbed by the first one-dimensional grating structure 31 at each incident light angle, and then is converted into a current output by the Schottky detector. Among them, the thickness of the metal material covering the one-dimensional semiconductor grating is greater than 20 nm and less than 100 nm. In the second case, due to the need for narrow-band absorption, the thickness of the metal material 311 should be larger, preferably > 50 nm.

[0055] In the third case, the first one-dimensional grating structure 31 can also be integrated with the first detector 21 in the manner Figure 4 shown, where 311’ is a dielectric material, and its material can be SiO 2 , SiN, etc., 312 is a metal material. A one-dimensional dielectric grating is integrally formed on the surface of the dielectric material 311’, and the metal material 312 covers the one-dimensional dielectric grating. The first detector 21 can be an InGaAs detector, etc. After the incident light passes through the first one-dimensional grating structure 31, it is transmitted to the first detector 21. Among them, the thickness of the metal material covering the one-dimensional dielectric grating is greater than 20 nm and less than 100 nm. In the third case, due to the need for narrow-band transmission, the thickness of the metal material 312 should be thinner, preferably < 40 nm.

[0056] Compared with Figure 2 the first one-dimensional grating structure shown, Figure 3 and Figure 4 the performance of the first one-dimensional grating structure shown is better.

[0057] Figure 5Shows a schematic diagram of an angle-sensitive one-dimensional grating structure in this exemplary embodiment. For incident light with a polarization direction perpendicular to the grating, the resonance wavelength is different at different incident angles. For this one-dimensional grating structure, narrowband incident light with a central wavelength of λ1 obtains resonance absorption (or transmission) at an incident angle of θ1, and narrowband incident light with central wavelengths of λ2 and λ3 respectively correspond to incident angles θ2 and θ3. For incident light with a polarization direction parallel to the grating (or both are in the same plane), resonance cannot be formed at any incident angle, presenting a high-reflection state.

[0058] As a specific implementation of this exemplary embodiment, please refer again to Figure 1 as shown, where the substrate 1 may further have a fixed part 12 and a rotating shaft 13. The fixed part 12 may have a frame structure, and the rotatable part 11 may be rotatably arranged in the frame structure through the rotating shaft 13. The first detector 21 and the second detector 22 are both integrally arranged on the rotatable part 11, and the first one-dimensional grating structure 31 and the second one-dimensional grating structure 32 are respectively integrally arranged on the first detector 21 and the second detector 22, thereby forming a first spectral detection unit (working unit) and a second spectral detection unit (denoising unit) respectively. More preferably, the two spectral detection units are symmetrically arranged on the surface of the rotatable part 11, and the surface of the rotatable part 11 is a plane, that is, the angles of the entire surface of the rotatable part 11 are exactly the same. And, the two spectral detection units should be as close as possible but not in contact with each other.

[0059] Furthermore, each detector may have at least two electrodes, and these electrodes also constitute the working electrodes of the corresponding spectral detection unit. If each detector has two electrodes, namely a first working electrode and a second working electrode, and the first working electrodes of the two detectors can be electrically connected to form a common electrode through the first electrode wiring 50 and are electrically connected to the first contact electrode 60 through the electrode wiring 50. The second working electrodes of the two detectors can be respectively electrically connected to the second contact electrodes 61 and 62 through the second electrode wirings 51 and 52. The aforementioned first contact electrode and second contact electrode are both arranged on the fixed part 12. The aforementioned first electrode wiring and second electrode wiring are both led out from the rotatable part 11 to the fixed part 12 through the rotating shaft 13.

[0060] Furthermore, when the detection chip is working, the rotatable part 11 rotates around the rotating shaft 13 under the driving signal and drives the two spectral detection units to rotate together. With respect to each one-dimensional grating structure, the angular change range of the incident light is the rotation angle range of the rotatable part 11. The electrical signals output by the two detectors at each rotation angle are recorded through each contact electrode. Since the incident light is linearly polarized light and its polarization direction is perpendicular to the first one-dimensional grating structure 31, the resonance wavelength of the first one-dimensional grating structure 31 is different at different rotation angles, so that the working unit can respond only to light of a specific wavelength at different rotation angles, realizing the scanning sampling of spectral information; for the second one-dimensional grating structure 32, the polarization direction of the incident light is parallel to the second one-dimensional grating structure 31, so no matter at what rotation angle, the second one-dimensional grating structure 32 presents a high reflection state and cannot form resonance. Since the structural design, process and real-time sampling process of the detectors and one-dimensional grating structures in the working unit and the noise reduction unit are exactly the same, the noise reduction unit collects noise signals that are highly consistent with the working unit, including the influence of system vibration, temperature change, light source change, dark current caused by the electrical structure of the detector, and photocurrent caused by the non-resonant absorption (transmission) light of the angle-sensitive structure. These are all noises that interfere with the detection accuracy. By differentiating the signals of the working unit and the noise reduction unit during the entire scanning sampling process, as Figures 6 - 8 shown, the purpose of noise suppression can be achieved, and finally a high signal-to-noise ratio can be obtained, so as to obtain higher-precision spectral information, as Figures 9 - 10 shown. The working unit and the noise reduction unit with the same structure prepared by the same process can be very close in terms of noise level, so the noise reduction effect is much better than that of the simple reference detector Ref with a light-shielding layer covered.

[0061] The technical solution of the present application will be further described in detail below in conjunction with several embodiments.

[0062] Embodiment 1

[0063] The structure of a scanning spectral detection chip provided in this embodiment can be referred to Figure 1, which includes a MEMS silicon micro-mirror fabricated on an SOI substrate. The rotatable part 11 in the silicon micro-mirror serves as the above-mentioned bearing mechanism. Its size is approximately 3000×3000×500μm, and the rotatable angle range is 0 - 30°. Correspondingly, the incident angle range of the incident light is [θ1, θ2], and θ1 and θ2 are approximately 0° and 30° respectively. On the surface of the bearing mechanism, 2 first detectors 21 and second detectors 22 with exactly the same material and structure are symmetrically arranged. These 2 detectors are both InGaAs detectors, and their detection wavelength ranges are both 900 - 1700nm. The distance between these 2 InGaAs detectors is approximately 50μm. At the same time, a first one-dimensional grating structure 31 and a second one-dimensional grating structure 32 are respectively integrated on the first detector 21 and the second detector 22, thus forming a first spectral detection unit and a second spectral detection unit respectively. The first spectral detection unit and the second spectral detection unit are respectively used as the working unit and the noise reduction unit. These two one-dimensional grating structures 31 and 32 are both formed of Au, and they have the same structure, but the grating orientations are orthogonal. Among them, the grating orientation of the first one-dimensional grating structure 31 is parallel to the rotation axis, and the grating orientation of the second one-dimensional grating structure 32 is perpendicular to the rotation axis. Further, the period of each one-dimensional grating structure is approximately 1100nm, the grating width is approximately 550nm, the grating depth is approximately 60nm, and the resonance wavelength range is approximately 1100 - 1600nm. The spectral detection range of this chip is 1100 - 1600nm.

[0064] Please refer to Figure 11 , when this detection chip is working, the working unit and the noise reduction unit rotate together with the bearing mechanism, so that the incident angle of the incident light varies between [θ1, θ3]. When the polarization direction of the incident light is perpendicular to the first one-dimensional grating structure, it can be defined as p-polarized light with respect to the first one-dimensional grating structure. If the central wavelengths of the incident light are λ1, λ2, or λ3 (or the incident light contains light with central wavelengths of λ1, λ2, or λ3, and λ1, λ2, and λ3 are approximately 1180nm, 1350nm, and 1520nm respectively), then the light with wavelengths of λ1, λ2, and λ3 respectively excite resonance at the incident angles θ1, θ2, and θ3 (θ1, θ2, and θ3 are approximately 5°, 15°, and 25° respectively), forming peak optoelectronic response signals. The Lorentz spectral shape represents the corresponding resonance broadening. At the same time, the polarization direction of the incident light is parallel to the second one-dimensional grating structure and cannot excite resonance in the noise reduction unit, so the noise reduction unit cannot generate an optoelectronic response signal accordingly.

[0065] Conversely, if the polarization direction of the incident light is parallel to the first one-dimensional grating structure, it can be defined as s-polarized light with respect to the first one-dimensional grating structure. At this time, incident light of any wavelength at any angle cannot excite resonance in the first spectral detection unit, and thus cannot cause any response signal in the first spectral detection unit. In this case, for the second one-dimensional grating structure, the polarization direction of the incident light may be perpendicular to it, and the incident light may excite resonance in the second spectral detection unit and cause a photoelectric response signal in the second spectral detection unit. Therefore, at this time, the first spectral detection unit can be used as a noise reduction unit, and the second spectral detection unit can be used as a working unit.

[0066] When using this detection chip to detect the light to be measured with an unknown spectrum, the spectral detection signals (mainly photocurrent signals) generated by the working unit, the noise reduction unit, and the reference device are respectively as Figure 12 shown by the corresponding curves of "spectral detection unit", "noise reduction unit", and "Ref" in. In this embodiment, the reference device is formed by covering a light-blocking layer on the same device as the working unit. Therefore, it can be used to perform sampling in the absence of light as noise. Using the existing noise reduction method, that is, taking the spectral detection signal generated by the reference device as noise and denoising the spectral detection signal generated by the working unit based on it, the spectrum of the light to be measured obtained after parsing is as Figure 12 shown by the curve of "spectral detection unit - Ref" in. Using the noise reduction method of this embodiment, that is, taking the spectral detection signal generated by the noise reduction unit as noise and denoising the spectral detection signal generated by the working unit based on it (mainly by subtracting the photocurrent signal output by the working unit from the photocurrent signal output by the noise reduction unit for denoising), the spectrum of the light to be measured obtained after parsing is as Figure 12 shown by the curve of "spectral detection unit - noise reduction unit" in. Obviously, using the noise reduction method of this embodiment can obtain a higher signal-to-noise ratio, and thus obtain more accurate spectral information.

[0067] Embodiment 2

[0068] The structure of a scanning spectral detection chip provided in this embodiment is basically the same as that in Embodiment 1. The rotatable angle range is 0 - 30°, and the corresponding incident angle range of the incident light is [θ1, θ2], where θ1 and θ2 are approximately 0° and 30° respectively. The difference is that the structure of each spectral detection unit is as Figure 3As shown, it includes a one-dimensional silicon material grating formed by front-side processing and a metal thin film covering the one-dimensional silicon material grating. The two form a Schottky detector through metal-semiconductor contact. The period of the one-dimensional silicon material grating is about 1100 nm, the grating width is about 550 nm, the grating depth is about 25 nm, and the thickness of the metal thin film is about 50 nm. The metal film in each detector also serves as its first working electrode, and the second working electrode of each detector can be formed by depositing metal materials such as Ti, Al, and Au on the back surface of the rotatable part. The wavelength range that the detection chip can scan is about 780 - 1080 nm.

[0069] Embodiment 3

[0070] The structure of a scanning spectroscopic detection chip provided in this embodiment is basically the same as that of Embodiment 1. The rotatable angle range is 0 - 30°, and the corresponding incident angle range of the incident light is [θ1, θ2], where θ1 and θ2 are about 0° and 30° respectively. The difference is that the structure of each spectroscopic detection unit is as Figure 4 shown. Each of them includes a detector arranged on the surface of the rotatable part 11 of the silicon micro-mirror and an angle-sensitive structure arranged on the detector. The 2 detectors use the same InGaAs detectors, and their detection wavelengths are both 900 - 1700 nm. Each one-dimensional grating structure includes a one-dimensional SiO2 grating and an Au film covering the one-dimensional SiO2 grating. The period of the one-dimensional SiO2 grating is about 1100 nm, the grating width is about 550 nm, the grating depth is about 60 nm, and the thickness of the Au film is about 30 nm. The wavelength range that can be scanned is about 1100 - 1600 nm.

[0071] It should be understood that the above embodiments are only used to illustrate the technical concept and features of the present application. The purpose is to enable those familiar with this technology to understand the content of the present application and implement it accordingly, and it cannot be used to limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A scanning spectrum detection chip with orthogonal grating polarization denoising, characterized in that: include: A supporting mechanism rotatable about a rotation axis, which is used at least for angular scanning relative to the direction of incident light; Two spectral detection units are arranged on the surface of the supporting mechanism at an interval, each of the spectral detection units includes a detector and an angle-sensitive one-dimensional grating structure, the one-dimensional grating structure is arranged on the detector, the materials and structures of the detectors and the one-dimensional grating structures contained in the two spectral detection units are the same, and the grating orientation of the one-dimensional grating structure contained in one spectral detection unit is orthogonal to the grating orientation of the one-dimensional grating structure contained in the other spectral detection unit.

2. The scanning spectrum detection chip according to claim 1, characterized in that: The distance between the two spectral detection units is 5μm~2mm; and / or, the two spectral detection units are symmetrically arranged on the surface of the supporting mechanism; and / or, the surface of the supporting mechanism is a plane; and / or, the two spectral detection units are respectively used as a working unit and a denoising unit, and the grating orientation of the one-dimensional grating structure in the working unit is parallel to the rotation axis, and the polarization direction of the incident light is perpendicular to the rotation axis.

3. The scanning spectrum detection chip according to claim 1, characterized in that: The one-dimensional grating structure in the spectrum detection unit is integrated on the detector.

4. The scanning spectrum detection chip according to claim 1, characterized in that: The detector in the spectrum detection unit includes a semiconductor material, a one-dimensional semiconductor grating is integrally formed on the surface of the semiconductor material, the one-dimensional grating structure includes the one-dimensional semiconductor grating and a metal material covered on the one-dimensional semiconductor grating, and the metal material forms a Schottky contact with the one-dimensional semiconductor grating; Alternatively, the one-dimensional grating structure includes a one-dimensional dielectric grating arranged on the detector and a metal material coated on the one-dimensional dielectric grating, and the one-dimensional dielectric grating is formed of a dielectric material.

5. The scanning spectrum detection chip according to claim 4, characterized in that: The thickness of the metal material coated on the one-dimensional semiconductor grating or the one-dimensional dielectric grating is greater than 20 nm and less than 100 nm.

6. The scanning spectrum detection chip according to any one of claims 1 to 5, characterized in that: The detector includes a photoelectric detector or a photothermoelectric detector.

7. The scanning spectrum detection chip according to claim 1, characterized in that: The detection chip comprises a substrate, and the substrate comprises a fixed part, a rotatable part and a rotating shaft. The rotatable part is the bearing mechanism and is rotatably mounted on the fixed part via the rotating shaft.

8. The scanning spectrum detection chip according to claim 7, characterized in that: The spectral detection unit has a first working electrode and a second working electrode, the first working electrode and the second working electrode are electrically connected to a first contact electrode and a second contact electrode via a first electrode wiring and a second electrode wiring, respectively, the first electrode wiring and the second electrode wiring both extend from the rotatable part to the fixed part along the rotating shaft, and the first contact electrode and the second contact electrode are respectively arranged on the fixed part.

9. The scanning spectrum detection chip according to claim 8, characterized in that: The first working electrodes of the two spectrum detection units are connected to each other to form a common electrode, and the common electrode is electrically connected to a first contact electrode via a first electrode wiring.

10. A spectrum detection method, characterized in that: The method is implemented based on the scanning spectrum detection chip according to any one of claims 1 to 9, and the method comprises: Allowing the light to be detected to enter the scanning spectrum detection chip; Rotating the supporting mechanism relative to the incident light to change the incident angle; The corresponding detection signal output by the scanning spectrum detection chip when the supporting mechanism rotates at each angle is recorded and analyzed to realize spectrum detection of the light to be detected.

11. The spectrum detection method according to claim 10, characterized in that: The method specifically comprises: The two spectral detection units are defined as a working unit and a denoising unit, respectively, wherein the one-dimensional grating structure contained in the working unit can resonate with the incident light and generate a photocurrent signal formed by resonant absorption or transmission, and the one-dimensional grating structure contained in the denoising unit cannot resonate with the incident light and will not generate a photocurrent signal formed by resonant absorption or transmission; The photocurrent signal output by the working unit is subtracted from the photocurrent signal output by the denoising unit to achieve denoising of the photocurrent signal output by the working unit, and then the spectrum of the light to be detected is analyzed.

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