A spectrometer

Abstract

The present invention discloses a spectrometer. The spectrometer includes a broadband light source, multiple bandpass filters, multiple microcavities, a driving source, and a spectral analysis system; the microcavity is connected to the spectral analysis system; a photodetector is provided in the middle of the microcavity, and the rest of the microcavity is filled with phase change material; the sample to be tested is provided between the broadband light source and the multiple bandpass filters, and the light emitted by the broadband light source is absorbed by the sample to be tested to generate light of different wavelengths to be tested. The light of different wavelengths to be tested passes through the multiple bandpass filters and is irradiated on the multiple microcavities. The crystallinity of the phase change material in the microcavity is changed by the driving source, thereby changing the refractive index of the phase change material, and then regulating the optical path and resonance frequency of the microcavity, as well as the wavelength of the absorption peak of the photoelectric conversion layer, to achieve selective detection of light of different wavelengths to be tested, thereby achieving spectral analysis. The present invention has a simple structure, and the preparation materials are compatible with mature semiconductor device production processes, which facilitates chip integration.

Description

Technical Field

[0001] The present invention relates to the field of spectrometer design, and in particular to a high-time-resolution, integrable micro-spectrometer. Background Art

[0002] A spectrometer is a scientific instrument that decomposes mixed wavelengths of light into spectral lines. It typically consists of a spectroscopic element, such as a prism or grating. Spectrometers can be used to measure the composition of an object or the structure of molecules, and are widely used in scientific research, environmental monitoring, and meteorological monitoring. Furthermore, high-time-resolution spectrometers can be used for process analysis of chemical reactions or biomacromolecule reactions, as well as fluorescence analysis, and have important applications in chemical and biological research, as well as in lighting and display.

[0003] With technological advances, the analysis of trace samples is becoming increasingly important, and miniaturization of analytical instruments is a growing trend. Furthermore, integration with chips can further improve analytical quality and efficiency. However, the spectroscopic components in traditional spectrometers, such as prisms or gratings, require long optical paths, resulting in large spectrometer sizes. Fourier transform spectrometers require a similar structure to a Michelson interferometer, which is also large. Miniaturization is not feasible, let alone integration with chips. Current miniaturized spectrometers primarily separate light of different wavelengths spatially. While these spectrometers offer high resolution, miniaturization is difficult. Separating light by wavelength within a small spatial area requires a highly dispersive element, which presents design challenges (Development of a Compact and Robust Mid-Infrared Spectrometer by Using a SiliconAir Hyperspectral Filter; Tunable Mid-Wave Infrared Fabry-Perot Bandpass Filters Using Phase-Change GeSbTe). Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-time-resolution, integrable micro-spectrometer, which mainly changes the optical path of the microcavity defect layer by changing the crystallinity of the phase-change material, thereby changing the resonant frequency of the microcavity and the wavelength of the absorption peak of the photoelectric conversion layer in the microcavity, so as to realize spectral analysis of the light to be measured.

[0005] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0006] A spectrometer includes a broadband light source, multiple bandpass filters, multiple microcavities, a driving source, and a spectrum analysis system; the microcavity is connected to the spectrum analysis system;

[0007] A photodetector is provided in the middle of the microcavity, and the rest of the interior of the microcavity is filled with phase change material to form a phase change material layer;

[0008] The photodetector includes an insulating isolation layer, a photoelectric conversion layer, and a photoelectric detection layer electrode. Insulating isolation layers are provided above and below the photoelectric conversion layer to isolate the photoelectric conversion layer from the phase change material layer. The insulating isolation layers can eliminate the effect of the phase change material layer on the current while reducing the effect of the phase change material layer on the light to be measured. A photoelectric detection layer electrode is connected to each end of the photoelectric conversion layer to measure the photocurrent.

[0009] The sample to be tested is placed between a broadband light source and multiple bandpass filters. The light emitted by the broadband light source is absorbed by the sample to generate light of different wavelengths to be tested. The light of different wavelengths to be tested passes through multiple bandpass filters and then irradiates multiple microcavities. The driving source changes the crystallinity of the phase change material in the microcavity of the integrated photodetector, thereby changing the refractive index of the phase change material. The optical path and resonance frequency of the microcavity, as well as the wavelength of the absorption peak of the photoelectric conversion layer, are then regulated to achieve selective detection of light of different wavelengths to be tested, thereby realizing spectral analysis.

[0010] Furthermore, the photodetector is located in the middle of the microcavity;

[0011] Inside the microcavity, the upper and lower parts of the photodetector are filled with phase change material to form an upper phase change material layer and a lower phase change material layer.

[0012] Furthermore, a Bragg reflector is provided at one end of the microcavity facing the light and at the other end opposite to the end facing the light, that is, the two Bragg reflectors are respectively closely attached to the upper phase change material layer and the lower phase change material layer.

[0013] Bragg reflectors have low light absorption, high Q value, and small half-width of the absorption peak, and are used to improve the wavelength resolution of spectrometers.

[0014] Furthermore, the optical path of the microcavity is within plus or minus 20% of 5 / 4 times the central wavelength.

[0015] Furthermore, the optical path of the microcavity is within plus or minus 20% of 1 / 2 times the central wavelength.

[0016] After increasing the optical path of the microcavity, when the refractive index of the phase change material changes, the optical path changes more and the range is larger; at the same time, increasing the optical path of the microcavity can increase the Q value of the microcavity, reduce the half-height width of the absorption spectrum line, and improve the resolution of the photodetector.

[0017] Furthermore, multiple bandpass filters rotate around a point, and the light emitted by the wide-spectrum light source passes through the sample to be tested to generate light of different wavelengths to be tested. The generated light of different wavelengths to be tested passes through the rotating multiple bandpass filters and then irradiates multiple microcavities, which is used to expand the detection range of the photodetector.

[0018] Furthermore, the photoelectric conversion layer is a single layer or multilayer graphene; the photoelectric conversion efficiency of the single layer or multilayer graphene in the infrared and visible light bands varies little with wavelength, the selective detection consistency of the wavelength is good, and the graphene is thin, does not require lattice matching, and is easy to integrate.

[0019] Furthermore, the driving source is a picosecond laser; the laser pulse of the picosecond laser is short. Driven by this driving source, the crystallinity of the phase change material changes very quickly, and the spectrometer can achieve nanosecond-level time resolution.

[0020] Furthermore, the phase change material is Sb2S3, which has very little light absorption in the infrared band. The ratio of the change in the real part of the refractive index to the change in the imaginary part under different phase changes is very large, which is conducive to improving the working wavelength range of the spectrometer and increasing the effective photoelectric conversion efficiency.

[0021] Furthermore, electrodes are provided at both ends of the phase change material layer and are connected to a high-speed resistance measurement system to measure the resistance of the phase change material in real time to monitor the crystallinity of the phase change material.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] The present invention utilizes phase-change materials, which offer high temporal resolution due to their rapid phase transitions. Separating light of different wavelengths temporally eliminates any special space requirements, allowing for very small dimensions. The spectrometer also boasts a simple structure, lacking moving parts, and its materials are compatible with established semiconductor device manufacturing processes, facilitating chip integration.

[0024] At the same time, since the crystallization speed of the phase change material is in the nanosecond order, the time response speed of the spectral analysis of the light to be measured can also reach the nanosecond order. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of a spectrometer in an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the structure of the microcavity in an embodiment of the present invention;

[0027] Figure 3 Schematic diagram of the change of the central wavelength of the graphene absorption peak with crystallinity in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following description, combined with specific illustrations, illustrates the technical solution to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and any similar generalizations made by persons of ordinary skill in the art without inventive effort are also within the scope of protection of the present invention.

[0029] The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this specification. As used in one or more embodiments of this specification and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in one or more embodiments of this specification refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0030] Example:

[0031] A spectrometer, such as Figure 1 As shown, it includes a broadband light source 1, four bandpass filters 2, four microcavities 3, a driving source 4, and a spectrum analysis system 5; the microcavity 3 is connected to the spectrum analysis system 5;

[0032] like Figure 2 As shown, a photodetector is provided in the middle of the microcavity 3, and the rest of the interior of the microcavity 3 is filled with a phase change material 6 to form a phase change material layer;

[0033] The photodetector includes an insulating isolation layer 7, a photoelectric conversion layer 8, and a photoelectric detection layer electrode 9. The insulating isolation layer 7 is provided above and below the photoelectric conversion layer 8 to isolate the photoelectric conversion layer 8 from the phase change material layer 6. The insulating isolation layer 7 can reduce the effect of the phase change material layer 6 on the light to be measured while eliminating the effect of the phase change material layer 6 on the current. A photoelectric detection layer electrode 9 is connected to each end of the photoelectric conversion layer 8 for measuring the photocurrent.

[0034] The sample to be tested is placed between a broadband light source 1 and four bandpass filters 2. Light emitted by the broadband light source 1 is absorbed by the sample to generate light of different wavelengths to be tested. The light of different wavelengths passes through the four bandpass filters 2 and then irradiates the four microcavities 3. The driving source 4 changes the crystallinity of the phase change material 6 in the microcavity 3 of the integrated photodetector, thereby changing the refractive index of the phase change material 6. In turn, the optical path and resonance frequency of the microcavity 3, as well as the wavelength of the absorption peak of the photoelectric conversion layer 8, are regulated to achieve selective detection of the light of different wavelengths to be tested, thereby realizing spectral analysis.

[0035] The photodetector is located in the middle of the microcavity 3;

[0036] Inside the microcavity 3, the upper and lower parts of the photodetector are filled with phase change material 6, forming an upper phase change material layer and a lower phase change material layer;

[0037] In this embodiment, Figure 2 As shown, a Bragg reflector 10 is provided at one end of the microcavity 3 facing the light and at the other end opposite to the end facing the light, that is, the two Bragg reflectors 10 are respectively closely attached to the upper phase change material layer and the lower phase change material layer.

[0038] The Bragg reflector 10 has low light absorption, high Q value, and small half-height width of the absorption peak, and is used to improve the wavelength resolution of the spectrometer.

[0039] In this embodiment, distributed Bragg reflectors 10 are disposed at both ends of the microcavity 3. The periods of the two Bragg reflectors 10, respectively adjacent to the upper and lower phase-change material layers, are different: the Bragg reflector 10 adjacent to the upper phase-change material layer has two periods, while the Bragg reflector 10 adjacent to the lower phase-change material layer has six periods. The Bragg reflectors 10 are composed of alternating Si with a refractive index of 3.50 and a thickness of 0.09 μm, and SiO2 with a refractive index of 1.47 and a thickness of 0.223 μm.

[0040] In this embodiment, the optical path of the microcavity 3 is within plus or minus 20% of 5 / 4 times the central wavelength.

[0041] After increasing the optical path of the microcavity 3, when the refractive index of the phase change material 6 changes, the optical path changes more and the range is larger; at the same time, increasing the optical path of the microcavity 3 can improve the Q value of the microcavity 3, reduce the half-height width of the absorption spectrum, and improve the resolution of the photodetector.

[0042] In this embodiment, four bandpass filters 2 rotate around a point. The light emitted by the broadband light source 1 passes through the sample to be tested to generate light of different wavelengths to be tested. The generated light of different wavelengths to be tested passes through the rotating four bandpass filters 2 and then irradiates the four microcavities 3, thereby expanding the detection range of the photodetector.

[0043] In this embodiment, the photoelectric conversion layer 8 is a single layer of graphene.

[0044] In this embodiment, the driving source 4 is a picosecond laser. The laser pulse of the picosecond laser is short. Driven by the driving source 4, the crystallinity of the phase change material 6 changes very quickly, and the spectrometer can achieve nanosecond-level time resolution.

[0045] In this embodiment, the phase change material 6 is Sb2S3. Sb2S3 has very little light absorption in the infrared band, and the ratio of the change in the real part of the refractive index to the change in the imaginary part under different phase changes is very large, which is conducive to improving the working wavelength range of the spectrometer and increasing the effective photoelectric conversion efficiency.

[0046] In this embodiment, the thickness of the upper phase-change material layer is 0.115 μm; the thickness of the lower phase-change material layer is 0.115 μm; and the insulating isolation layer 7 is made of SiO 2 and has a thickness of 10 nm.

[0047] In this embodiment, electrodes are provided at both ends of the phase change material layer and are connected to a high-speed resistance measurement system to measure the resistance of the phase change material in real time to monitor the crystallinity of the phase change material.

[0048] In this embodiment, the wavelength range of the broadband light source 1 is 1.1-1.8 microns, and the passbands of the four bandpass filters 2 are 1.10-1.25 microns, 1.25-1.40 microns, 1.40-1.65 microns, and 1.65-1.80 microns, respectively. The bandpass filters 2 are rotated to allow light of different wavelengths to illuminate the microcavity 3 with four integrated photodetectors. Simultaneously, a picosecond laser drive source 4 drives the crystallinity of the phase-change material 6 to change. A spectral analysis system 5 measures the real-time changes in the active photocurrent and analyzes the spectrum of light emitted by the sample under test or the light source under test, i.e., the broadband light source 1, after irradiating the sample. The advantage of using four rotating bandpass filters 2 and four microcavities 3 with integrated photodetectors is that the wavelength range of spectral measurement can be effectively expanded.

[0049] In this embodiment, when the optical path of the photonic crystal microcavity is 5 / 4 times the central wavelength, the central wavelength of the graphene absorption peak changes with the crystallinity as shown in the following figure: Figure 3 As shown, the linear fitting relationship between the central wavelength and the crystallinity is y=0.140x+1.16, and the linear correlation coefficient is as high as 0.998.

[0050] Example 2:

[0051] A spectrometer, such as Figure 1 As shown, it includes a broadband light source 1, five bandpass filters 2, five microcavities 3, a driving source 4, and a spectrum analysis system 5; the microcavity 3 is connected to the spectrum analysis system 5;

[0052] like Figure 2 As shown, a photodetector is provided in the middle of the microcavity 3, and the rest of the interior of the microcavity 3 is filled with a phase change material 6 to form a phase change material layer;

[0053] The photodetector includes an insulating isolation layer 7, a photoelectric conversion layer 8, and a photoelectric detection layer electrode 9. The insulating isolation layer 7 is provided above and below the photoelectric conversion layer 8 to isolate the photoelectric conversion layer 8 from the phase change material layer 6. The insulating isolation layer 7 can reduce the effect of the phase change material layer 6 on the light to be measured while eliminating the effect of the phase change material layer 6 on the current. A photoelectric detection layer electrode 9 is connected to each end of the photoelectric conversion layer 8 for measuring the photocurrent.

[0054] The sample to be tested is placed between a broadband light source 1 and five bandpass filters 2. Light emitted by the broadband light source 1 is absorbed by the sample to generate light of different wavelengths to be tested. The light of different wavelengths passes through the five bandpass filters 2 and then irradiates the five microcavities 3. The crystallinity of the phase change material 6 in the microcavity 3 of the integrated photodetector is changed by a driving source 4, thereby changing the refractive index of the phase change material 6. In turn, the optical path and resonance frequency of the microcavity 3, as well as the wavelength of the absorption peak of the photoelectric conversion layer 8, are regulated to achieve selective detection of the light of different wavelengths to be tested, thereby realizing spectral analysis.

[0055] The photodetector is located in the middle of the microcavity 3;

[0056] Inside the microcavity 3, the upper and lower parts of the photodetector are filled with phase change material 6, forming an upper phase change material layer and a lower phase change material layer;

[0057] In this embodiment, Figure 2 As shown, a Bragg reflector 10 is provided at one end of the microcavity 3 facing the light and at the other end opposite to the end facing the light, that is, the two Bragg reflectors 10 are respectively closely attached to the upper phase change material layer and the lower phase change material layer.

[0058] The Bragg reflector 10 has low light absorption, high Q value, and small half-height width of the absorption peak, and is used to improve the wavelength resolution of the spectrometer.

[0059] In this embodiment, distributed Bragg reflectors 10 are disposed at both ends of the microcavity 3. The periods of the two Bragg reflectors 10, respectively adjacent to the upper and lower phase-change material layers, are different: the Bragg reflector 10 adjacent to the upper phase-change material layer has two periods, while the Bragg reflector 10 adjacent to the lower phase-change material layer has six periods. The Bragg reflectors 10 are composed of alternating Si with a refractive index of 3.50 and a thickness of 0.09 μm, and SiO2 with a refractive index of 1.47 and a thickness of 0.223 μm.

[0060] In this embodiment, the optical path of the microcavity 3 is within plus or minus 20% of 1 / 2 times the central wavelength.

[0061] After increasing the optical path of the microcavity 3, when the refractive index of the phase change material 6 changes, the optical path changes more and the range is larger; at the same time, increasing the optical path of the microcavity 3 can improve the Q value of the microcavity 3, reduce the half-height width of the absorption spectrum, and improve the resolution of the photodetector.

[0062] In this embodiment, five bandpass filters 2 rotate around a point. The light emitted by the broadband light source 1 passes through the sample to be tested to generate light of different wavelengths to be tested. The generated light of different wavelengths to be tested passes through the rotating five bandpass filters 2 and then irradiates the five microcavities 3, thereby expanding the detection range of the photodetector.

[0063] In this embodiment, the photoelectric conversion layer 8 is a single layer of graphene.

[0064] Example 2:

[0065] A spectrometer, such as Figure 1 As shown, it includes a broadband light source 1, 6 bandpass filters 2, 6 microcavities 3, a driving source 4, and a spectrum analysis system 5; the microcavity 3 is connected to the spectrum analysis system 5;

[0066] like Figure 2 As shown, a photodetector is provided in the middle of the microcavity 3, and the rest of the interior of the microcavity 3 is filled with a phase change material 6 to form a phase change material layer;

[0067] The photodetector includes an insulating isolation layer 7, a photoelectric conversion layer 8, and a photoelectric detection layer electrode 9. The insulating isolation layer 7 is provided above and below the photoelectric conversion layer 8 to isolate the photoelectric conversion layer 8 from the phase change material layer 6. The insulating isolation layer 7 can reduce the effect of the phase change material layer 6 on the light to be measured while eliminating the effect of the phase change material layer 6 on the current. A photoelectric detection layer electrode 9 is connected to each end of the photoelectric conversion layer 8 for measuring the photocurrent.

[0068] The sample to be tested is placed between a broadband light source 1 and six bandpass filters 2. Light emitted by the broadband light source 1 is absorbed by the sample to generate light of different wavelengths to be tested. The light of different wavelengths passes through the six bandpass filters 2 and then irradiates the six microcavities 3. The crystallinity of the phase change material 6 in the microcavity 3 of the integrated photodetector is changed by a driving source 4, thereby changing the refractive index of the phase change material 6. In turn, the optical path and resonance frequency of the microcavity 3, as well as the wavelength of the absorption peak of the photoelectric conversion layer 8, are regulated to achieve selective detection of light of different wavelengths to achieve spectral analysis.

[0069] The photodetector is located in the middle of the microcavity 3;

[0070] Inside the microcavity 3, the upper and lower parts of the photodetector are filled with phase change material 6, forming an upper phase change material layer and a lower phase change material layer;

[0071] In this embodiment, Figure 2 As shown, a Bragg reflector 10 is provided at one end of the microcavity 3 facing the light and at the other end opposite to the end facing the light, that is, the two Bragg reflectors 10 are respectively closely attached to the upper phase change material layer and the lower phase change material layer.

[0072] The Bragg reflector 10 has low light absorption, high Q value, and small half-height width of the absorption peak, and is used to improve the wavelength resolution of the spectrometer.

[0073] In this embodiment, distributed Bragg reflectors 10 are disposed at both ends of the microcavity 3. The periods of the two Bragg reflectors 10, respectively adjacent to the upper and lower phase-change material layers, are different: the Bragg reflector 10 adjacent to the upper phase-change material layer has two periods, while the Bragg reflector 10 adjacent to the lower phase-change material layer has six periods. The Bragg reflectors 10 are composed of alternating Si with a refractive index of 3.50 and a thickness of 0.09 μm, and SiO2 with a refractive index of 1.47 and a thickness of 0.223 μm.

[0074] In this embodiment, the optical path of the microcavity 3 is within plus or minus 20% of 1 / 2 times the central wavelength.

[0075] After increasing the optical path of the microcavity 3, when the refractive index of the phase change material 6 changes, the optical path changes more and the range is larger; at the same time, increasing the optical path of the microcavity 3 can improve the Q value of the microcavity 3, reduce the half-height width of the absorption spectrum, and improve the resolution of the photodetector.

[0076] In this embodiment, six bandpass filters 2 rotate around a point. The light emitted by the broadband light source 1 passes through the sample to be tested to generate light of different wavelengths to be tested. The generated light of different wavelengths to be tested passes through the rotating five bandpass filters 2 and then irradiates the six microcavities 3, which is used to expand the detection range of the photodetector.

[0077] In this embodiment, the photoelectric conversion layer 8 is multi-layer graphene.

[0078] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered equivalent replacement methods and are included in the scope of protection of the present invention.

[0079] The preferred embodiments of the present application disclosed above are intended only to facilitate understanding of the present invention and its core concepts. Those skilled in the art will appreciate that specific application scenarios and implementations may vary based on the principles of the present invention, and this description should not be construed as limiting the present invention. The present invention is intended to be limited only by the claims and their full scope and equivalents.

Claims

1. A spectrometer, characterized in that: It comprises a broadband light source (1), a plurality of bandpass filters (2), a plurality of microcavities (3), a driving source (4), and a spectrum analysis system (5); the microcavity (3) is connected to the spectrum analysis system (5); A photodetector is provided in the middle of the microcavity (3), and the remaining positions inside the microcavity (3) are filled with a phase change material (6) to form a phase change material layer; The photodetector comprises an insulating isolation layer (7), a photoelectric conversion layer (8) and a photoelectric detection layer electrode (9), wherein the photoelectric conversion layer (8) is provided with an insulating isolation layer (7) above and below to isolate the photoelectric conversion layer (8) from the phase change material layer. The insulating isolation layer (7) can reduce the influence of the phase change material layer on the light to be measured while eliminating the influence of the phase change material layer on the current. The two ends of the photoelectric conversion layer (8) are respectively connected to a photoelectric detection layer electrode (9) for measuring the photocurrent. The sample to be tested is arranged between a wide-spectrum light source (1) and a plurality of band-pass filters (2). Light emitted by the wide-spectrum light source (1) is absorbed by the sample to be tested to generate light of different wavelengths to be tested. The light of different wavelengths to be tested passes through the plurality of band-pass filters (2) and is irradiated onto a plurality of microcavities (3). The crystallinity of the phase change material (6) in the microcavity (3) is changed by a driving source (4), thereby changing the refractive index of the phase change material (6), and further regulating the optical path and resonance frequency of the microcavity (3) and the wavelength of the absorption peak of the photoelectric conversion layer (8), so as to achieve selective detection of the light of different wavelengths to be tested, thereby achieving spectral analysis.

2. A spectrometer according to claim 1, characterized in that: The photodetector is located in the middle of the microcavity (3); Inside the microcavity (3), the upper and lower parts of the photodetector are filled with phase change material (6), forming an upper phase change material layer and a lower phase change material layer.

3. A spectrometer according to claim 2, characterized in that: Bragg reflectors (10) are provided at one end of the microcavity (3) facing the light and at the other end opposite to the end facing the light, that is, the two Bragg reflectors (10) are respectively closely attached to the upper phase change material layer and the lower phase change material layer.

4. A spectrometer according to claim 1, characterized in that: The optical path of the microcavity (3) is within plus or minus 20% of 5 / 4 times the central wavelength.

5. A spectrometer according to claim 1, characterized in that: The optical path of the microcavity (3) is within plus or minus 20% of 1 / 2 times the central wavelength.

6. A spectrometer according to claim 1, characterized in that: A plurality of band-pass filters (2) rotate around a point, and light emitted by a wide-spectrum light source (1) passes through a sample to be tested to generate light of different wavelengths to be tested. The generated light of different wavelengths to be tested passes through the rotating plurality of band-pass filters (2) and then irradiates the plurality of microcavities (3), thereby expanding the detection range of the photodetector.

7. A spectrometer according to claim 1, characterized in that: The photoelectric conversion layer (8) is a single layer or multiple layers of graphene.

8. A spectrometer according to claim 1, characterized in that: The driving source (4) is a picosecond laser.

9. The spectrometer according to claim 1, characterized in that: The phase change material (6) is Sb2S3. Sb2S3 has very little light absorption in the infrared band. The ratio of the change in the real part of the refractive index to the change in the imaginary part under different phase changes is very large, which is conducive to improving the working wavelength range of the spectrometer and increasing the effective photoelectric conversion efficiency.

10. The spectrometer according to claim 1, wherein: Electrodes are provided at both ends of the phase change material layer and are connected to a high-speed resistance measurement system to measure the resistance of the phase change material in real time to monitor the crystallinity of the phase change material.

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