Optical fiber type integrated dispersion type Raman spectrometer with built-in reference light path

Abstract

The invention relates to an optical fiber type integrated dispersion type Raman spectrometer with a built-in reference light path, and the spectrometer comprises a laser module which is used for providing a plurality of excitation light sources; the collecting module is used for collecting multiple paths of excitation light sources to one optical fiber; the beam splitting module is used for carrying out beam splitting on the collected excitation light source according to a preset proportion to obtain a first excitation light source and a second excitation light source; the Raman scattering light generation module is used for inputting the first excitation light source into the reference channel to generate first Raman scattering light and inputting the second excitation light source into the sample detection channel to generate second Raman scattering light; the Raman scattering light filtering module is used for filtering the first Raman scattering light and the second Raman scattering light respectively; the Raman scattering light collimation module is used for carrying out collimation processing on the filtered first Raman scattering light and second Raman scattering light; and the Raman scattering light detection module is used for simultaneously carrying out spectrum detection on the aligned first Raman scattering light and the aligned second Raman scattering light and outputting a detection result.

Description

Technical Field

[0001] The present invention relates to the technical field of Raman spectrometers, and particularly to a fiber-integrated dispersive Raman spectrometer with a built-in reference optical path. Background Art

[0002] Most of the existing miniaturized Raman spectrometers are based on relatively large dispersive optical elements, usually requiring slits or pinholes and gratings or prisms as dispersive elements. Compared with traditional optical-based devices, on-chip dispersive spectrometers have significant potential for reduction in size, weight, and power consumption. Currently, a variety of ultra-compact on-chip spectrometer concepts have been proposed, such as on-chip dispersive spectrometers based on echelle gratings, concave plane gratings, and arrayed waveguide gratings, which can provide low-cost on-chip spectral analysis solutions in the visible and near-infrared spectral ranges. However, these devices suffer from severe signal-to-noise ratio (SNR) losses when acquiring high-resolution spectra due to the dispersion of the input light over multiple spectral channels. In addition, since the spectral resolution is inversely proportional to the optical path length and each channel requires a separate photodetector, the device size and system complexity increase linearly with the number of spectral channels. Moreover, in existing miniaturized dispersive Raman spectrometers, a laser stabilization device (such as a temperature control system) is generally required to ensure the stability of the output wavelength and power of the laser, while the laser stabilization device has the disadvantages of high cost, large volume, and high energy consumption, hindering the process of miniaturization and cost reduction; if an unstabilized miniaturized laser diode is used, although the cost is reduced, there are problems such as laser wavelength drift, mode hopping, and intensity fluctuations, and the accuracy of spectral detection cannot be guaranteed.

[0003] In summary, although miniaturized dispersive Raman spectrometers have been realized through different approaches, they all have limitations to varying degrees, and there is still no solution that can balance miniaturization, high throughput, and low cost up to now. Therefore, the present invention proposes a fiber-integrated dispersive Raman spectrometer with a built-in reference optical path. Summary of the Invention

[0004] The object of the present invention is to provide a fiber-integrated dispersive Raman spectrometer with a built-in reference optical path, which can achieve the balance of miniaturization, high precision, wide detection range, and low cost.

[0005] To achieve the above object, the present invention provides the following solution:

[0006] A fiber-integrated dispersive Raman spectrometer with a built-in reference optical path, comprising:

[0007] A laser module for providing multiple excitation light sources;

[0008] A converging module for converging the multiple excitation light sources onto one optical fiber;

[0009] A beam splitting module for splitting the aggregated excitation light source according to a preset ratio to obtain a first excitation light source and a second excitation light source;

[0010] A Raman scattering light generation module for inputting the first excitation light source into a reference channel to generate first Raman scattering light, and inputting the second excitation light source into a sample detection channel to generate second Raman scattering light, wherein the reference channel is used to provide a reference sample, and the sample detection channel is used to provide a sample to be measured;

[0011] A Raman scattering light filtering module for respectively filtering the first Raman scattering light and the second Raman scattering light;

[0012] A Raman scattering light collimating module for collimating the filtered first Raman scattering light and the second Raman scattering light;

[0013] A Raman scattering light detection module for simultaneously performing spectral detection on the collimated first Raman scattering light and the second Raman scattering light and outputting a detection result.

[0014] Optionally, the laser module includes a plurality of lasers for providing excitation light sources with different wavelengths.

[0015] Optionally, the aggregation module includes any one of a wavelength division multiplexer and a beam combiner, and the wavelength division multiplexer and the beam combiner are used to combine the output optical fibers of multiple lasers into a single optical fiber.

[0016] Optionally, the beam splitting module includes an optical fiber beam splitter for distributing the excitation light source to the reference channel and the sample detection channel according to a preset ratio.

[0017] Optionally, the Raman scattering light generation module includes a first optical fiber circulator and a second optical fiber circulator, wherein the first optical fiber circulator is used to provide unidirectional transmission for the first excitation light source and the first Raman scattering light respectively; the second optical fiber circulator is used to provide unidirectional transmission for the second excitation light source and the second Raman scattering light respectively.

[0018] Optionally, the Raman scattering light collimating module includes a first collimator and a second collimator, wherein the first collimator is used to collimate the filtered first Raman scattering light into a first parallel light; the second collimator is used to collimate the filtered second Raman scattering light into a second parallel light.

[0019] Optionally, the Raman scattering light detection module includes a dispersion element, a lens and a detector connected in sequence, inputting the parallel light into the dispersion element for dispersion spectroscopy, and then using the lens to focus the signals of the reference channel and the sample detection channel on two rows of pixel points of the detector.

[0020] Optionally, the Raman scattered light filtering module includes a first fiber optic band-pass filter and a second fiber optic band-pass filter. Among them, the first fiber optic band-pass filter is used to filter the first Raman scattered light to obtain the first Raman scattered light with a wavelength greater than the output wavelength of the laser; the second fiber optic band-pass filter is used to filter the second Raman scattered light to obtain the second Raman scattered light with a wavelength greater than the output wavelength of the laser.

[0021] Alternatively, the Raman scattered light filtering module includes a long-pass filter, which is used to filter the first Raman scattered light and the second Raman scattered light to obtain the first Raman scattered light and the second Raman scattered light with a wavelength greater than the output wavelength of the laser.

[0022] Alternatively, the Raman scattered light filtering module includes a first notch filter and a second notch filter. Among them, the first notch filter and the second notch filter are used to reflect the first excitation light source, the second excitation light source, and the Rayleigh scattered light. Both the first notch filter and the second notch filter include an optical switch, a fiber Bragg grating, and a beam combiner connected in sequence, where n fiber Bragg gratings are connected in parallel.

[0023] The beneficial effects of the present invention are as follows:

[0024] The present invention introduces a built-in real-time calibration reference channel to simultaneously obtain the Raman spectral information of the reference sample and the sample to be measured in a dispersive spectrometer. By comparing the obtained Raman spectrum of the reference sample with its known spectrum, the wavenumber calibration and intensity calibration of the main channel are further carried out, solving the problems of wavelength drift, mode hopping, and intensity fluctuation caused by using an unstabilized laser diode; using optical fibers to build the optical path realizes the simultaneous acquisition of the Raman signals of the reference sample and the sample to be measured, and is conducive to the further miniaturization of the Raman spectrometer; using the fiber optic wavelength division multiplexing technology realizes the switching of multiple lasers with different wavelengths, expanding the Raman spectral detection range and meeting the detection requirements of various substances; reasonably designing the filter elements, such as using fiber optic filters and Bragg gratings, realizes the filtering of other non-related signals such as the excitation light source and Rayleigh scattering, and meets the requirements of switching multiple lasers with different wavelengths and the miniaturization of the overall structure design. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1Schematic diagram of the structure of a fiber - integrated dispersive Raman spectrometer with an internal reference optical path according to an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the structure of a fiber - integrated dispersive Raman spectrometer with an internal reference optical path according to an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the structure of a fiber - integrated dispersive Raman spectrometer with an internal reference optical path according to an embodiment of the present invention;

[0029] Figure 4 Schematic diagram of the optical structure of the spectrometer according to an embodiment of the present invention;

[0030] Figure 5 Simulated optical trace diagram according to an embodiment of the present invention;

[0031] Figure 6 Spot diagram according to an embodiment of the present invention. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] To make the above - mentioned objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0034] This embodiment provides a fiber - integrated dispersive Raman spectrometer with an internal reference optical path, as shown in Figure 1 , Figure 2 , Figure 3 and includes:

[0035] A laser module for providing multiple excitation light sources;

[0036] An aggregation module for aggregating multiple excitation light sources onto one optical fiber;

[0037] A beam - splitting module for splitting the aggregated excitation light source according to a preset ratio to obtain a first excitation light source and a second excitation light source;

[0038] A Raman scattering light generation module for inputting the first excitation light source into a reference channel to generate first Raman scattering light, and inputting the second excitation light source into a sample detection channel to generate second Raman scattering light, where the reference channel is used to provide a reference sample, and the sample detection channel is used to provide a sample to be measured;

[0039] A Raman scattering light filtering module for filtering the first Raman scattering light and the second Raman scattering light respectively;

[0040] A Raman scattering light collimating module for collimating the filtered first Raman scattering light and second Raman scattering light;

[0041] A Raman scattering light detecting module for simultaneously performing spectral detection on the collimated first Raman scattering light and second Raman scattering light and outputting a detection result.

[0042] Specifically, in this embodiment, a built-in real-time calibration reference channel is introduced to simultaneously obtain the Raman spectral information of the reference sample and the sample to be measured in a dispersive spectrometer. By comparing the obtained Raman spectrum of the reference sample with its known spectrum, the wavenumber calibration and intensity calibration of the main channel are further carried out, solving the problems of wavelength drift, mode hopping and intensity fluctuation caused by using an unstabilized laser diode; using optical fibers to build the optical path realizes the simultaneous acquisition of the Raman signals of the reference sample and the sample to be measured, and is beneficial to the further miniaturization of the Raman spectrometer; using the fiber optic wavelength division multiplexing technology realizes the switching of multiple lasers with different wavelengths, expands the Raman spectral detection range, and can meet the detection requirements of various substances; reasonably designing the filtering elements, such as using fiber optic filters and Bragg gratings, realizes the filtering of the excitation light source and other non-related signals such as Rayleigh scattering, and meets the requirements of switching multiple lasers with different wavelengths and the miniaturization of the overall structure design.

[0043] Further, the laser module includes several lasers for providing excitation light sources with different wavelengths.

[0044] Specifically, in a Raman spectrometer, the laser is the core component of the excitation light source, and its selection directly affects the performance of the system. In order to ensure that the excitation light source can meet the needs of different samples, in this embodiment, the laser can adopt laser diodes with multiple wavelengths or other types of lasers. For example, common excitation wavelengths include 532nm, 638nm, 785nm, 830nm, etc. Using a laser with a longer wavelength can significantly reduce the fluorescence background of the sample, thereby improving the contrast and sensitivity of the Raman signal. In addition, the wavelength selection also needs to consider the interaction between the Raman shift of the sample and the excitation light to optimize the intensity and resolution of the Raman signal.

[0045] Further, the multiplexing module includes any one of a wavelength division multiplexer and a beam combiner, and the wavelength division multiplexer and the beam combiner are used to combine the output optical fibers of multiple lasers into a single optical fiber.

[0046] Specifically, to achieve the integration of multiple laser sources and reduce system complexity, a wavelength division multiplexer or a beam combiner can be used, including components such as a multi-wavelength beam combiner, a multi-mode fiber beam combiner, a single-mode fiber beam combiner, or an optical switch. Through these components, the output fibers of multiple lasers can be combined into a single fiber, thus simplifying the optical path design.

[0047] Further, the beam splitting module includes an optical fiber beam splitter, which is used to distribute the excitation light source to the reference channel and the sample detection channel according to a preset ratio.

[0048] Specifically, the beam splitting module functions to distribute the laser source beam to the reference channel and the main channel fiber paths according to a certain intensity ratio. Common components include optical fiber couplers and optical fiber splitters, etc.

[0049] Further, the Raman scattering light generation module includes a first optical fiber circulator and a second optical fiber circulator. Among them, the first optical fiber circulator is used to provide unidirectional transmission for the first excitation light source and the first Raman scattering light respectively; the second optical fiber circulator is used to provide unidirectional transmission for the second excitation light source and the second Raman scattering light respectively.

[0050] Specifically, the optical fiber circulator is an important component designed to ensure unidirectional transmission of signals in the optical fiber, avoid signal interference between different optical fiber paths, and ensure that Raman signals in a relatively large wavelength range can be transmitted. A broadband multi-mode optical fiber circulator, etc., can be used.

[0051] Further, as Figure 1 shown, the Raman scattering light filtering module includes a first optical fiber band-pass filter and a second optical fiber band-pass filter. Among them, the first optical fiber band-pass filter is used to filter the first Raman scattering light to obtain the first Raman scattering light with a wavelength greater than the output wavelength of the laser; the second optical fiber band-pass filter is used to filter the second Raman scattering light to obtain the second Raman scattering light with a wavelength greater than the output wavelength of the laser.

[0052] As another alternative embodiment, as Figure 2 shown, the Raman scattering light filtering module includes a long-pass filter, which is used to filter the first Raman scattering light and the second Raman scattering light to obtain the first Raman scattering light and the second Raman scattering light with wavelengths greater than the output wavelength of the laser.

[0053] As another alternative embodiment, as Figure 3As shown, the Raman scattered light filtering module includes a first notch filter and a second notch filter. Among them, the first notch filter and the second notch filter are used to reflect the first excitation light source, the second excitation light source, and Rayleigh scattered light. The first notch filter and the second notch filter both include an optical switch, a fiber Bragg grating, and a beam combiner connected in sequence, where n fiber Bragg gratings are connected in parallel.

[0054] Specifically, for the above three example solutions, the purpose is to filter out the excitation light source and Rayleigh scattered light on the premise of ensuring that the laser can be switched to expand the Raman spectrum detection range, and improve the signal-to-noise ratio and detection accuracy.

[0055] (1) Use a fiber bandpass or longpass filter to ensure that the lowest wavelength of its passband is greater than the output wavelengths of all lasers. When any laser is used, the collected Raman scattered light has a changed wavelength. Integrating the filter in the optical fiber improves the space utilization rate and facilitates further miniaturization.

[0056] (2) Place a longpass filter in the dispersive spectrometer, and its cut-off wavelength is greater than the output wavelengths of all lasers. The reference channel and the main channel can share one filter, which simplifies the optical path.

[0057] (3) Use a fiber Bragg grating as a notch filter to reflect the excitation light source and Rayleigh scattered light to prevent them from entering the dispersive spectrometer. The reflection wavelength of the Bragg grating should match the output wavelength of the laser one by one, and an optical switch is used to switch different Bragg gratings.

[0058] Furthermore, the Raman scattered light collimation module includes a first collimator and a second collimator. Among them, the first collimator is used to collimate the filtered first Raman scattered light into first parallel light; the second collimator is used to collimate the filtered second Raman scattered light into second parallel light.

[0059] Furthermore, the Raman scattered light detection module includes a dispersive element, a lens, and a detector connected in sequence. The parallel light is input into the dispersive element for dispersive spectroscopy, and then the lens is used to focus the signals of the reference channel and the sample detection channel on two rows of pixel points of the detector.

[0060] Specifically, the dispersive element is used to achieve the wavelength space separation of Raman signals. A dispersive element with high dispersive resolution and high dispersive efficiency is selected to improve the resolution and accuracy of the spectrum, which is the key to realizing high-sensitivity Raman spectrum testing. Common dispersive elements include prisms, reflection gratings, and transmission gratings, etc.

[0061] The reference sample needs to have known high-quality Raman spectroscopy data and provide identifiable marker points in the spectrum. Substances with obvious characteristic peaks such as cyclohexane, polystyrene, and naphthalene can be selected.

[0062] The detector can be a CMOS, CCD, or other type of sensor, ensuring that it has a high quantum efficiency within the detection wavelength range, has a small pixel area to improve the spectral resolution, has a length matching the designed Raman signal wavelength detection range, and can receive and process two Raman signals simultaneously.

[0063] For the selection of optical fibers, at the sample signal collection end, multimode optical fibers can be used to improve the collection range and efficiency. Since optical fiber filters and Bragg gratings are usually fabricated in single-mode optical fibers, single-mode optical fibers can be selected for other signal transmission paths. For the optical fiber connecting the dispersive spectrometer, an optical fiber with a lower core diameter can be directly used as the slit input to the dispersive spectrometer, which can improve the resolution and the optical flux, and further improve the signal-to-noise ratio. For the conversion between multimode and single-mode optical fibers, components such as optical fiber mode converters, optical fiber couplers, and mode conversion optical fiber jumpers can be used.

[0064] The phenomenon that the frequency of scattered light changes when light interacts with matter is called the Raman effect. Raman scattered light is a kind of inelastic scattered light, and there is an energy exchange with matter, so signal light with a wavelength different from that of the excitation light will be generated. Since Raman scattering is very weak, a laser with concentrated intensity becomes an ideal excitation light source for Raman spectroscopy detection. Especially in weakly scattering samples or low-concentration samples, it is particularly important to improve the signal-to-noise ratio by increasing the optical flux and using a high-sensitivity sensor. The energy difference between the excitation light source and the Raman scattered light depends on the vibration of the matter itself, so Raman spectroscopy can realize qualitative and quantitative testing of substances.

[0065] In this embodiment, the Raman scattered light of the reference sample and the sample to be measured is generated by splitting the beam of the same laser source, and the splitting ratio is known. After dispersing the two-channel signals, they are compressed onto two rows of pixel points of the CMOS or CCD sensor, and the Raman spectra of the reference sample and the sample to be measured are obtained simultaneously. The reference sample is selected as a substance with obvious characteristic peaks in the Raman spectrum. Since the wavelength of the excitation light source in the reference channel and the main channel is always the same, by comparing the deviation of the characteristic peak position in the measured Raman spectrum of the reference sample and its known Raman spectrum, the wavenumber calibration of the reference channel and the main channel can be realized, and the influence caused by the wavelength drift of the laser is reduced. The specific wavenumber calibration process is as follows:

[0066] The Raman shift corresponding to the characteristic peak of the measured reference sample is The Raman shift corresponding to this characteristic peak in its known standard spectrum is Then the wavenumber offset:

[0067]

[0068] By translating the Raman spectrum of the sample to be measured obtained from the main channel by Δv, wavenumber calibration can be achieved.

[0069] Meanwhile, since the intensity ratio of the excitation light sources in the two channels is known, by measuring the signal intensity in the reference channel, intensity calibration of the Raman signal in the main channel can be achieved, providing conditions for quantitative measurement of substances. The intensity calibration process is as follows:

[0070] The measured intensity of the Raman spectrum of the reference sample is I ref , and its known standard Raman spectrum intensity is I0, then the intensity offset:

[0071] ΔI = I ref - I0;

[0072] By translating the Raman spectrum of the sample to be measured obtained from the main channel by ΔI, intensity calibration can be achieved.

[0073] Meanwhile, since the fluorescence wavelength does not change with the change of the excitation light wavelength, but the Raman scattered light wavelength changes with the change of the excitation light wavelength, when the laser wavelength drifts, it is possible to distinguish the Raman spectrum and the fluorescence spectrum, so that the background fluorescence spectrum can be subtracted from the obtained Raman spectrum to improve the signal-to-noise ratio. Since the original spectrum of the reference channel is known, the deconvolution deblurring algorithm can be used to further improve the resolution and signal-to-noise ratio of the Raman spectrum.

[0074] Verification:

[0075] The free-space signal output from the optical fiber is coupled into the scattering spectrometer. By using a spherical mirror, the resolution can be reduced to 0.8 nm, meeting the application requirements of high-resolution Raman spectroscopy. The optical path is as Figure 4 shown. The optical fiber signal input is reflected by spherical mirror 1 to the reflection grating, then reflected by the reflection grating to spherical mirror 2, and then reflected by spherical mirror 2 into the cylindrical lens and then reaches the detector.

[0076] By verifying the spectroscopic signals on the detector, it can be seen that the designed optical path can image the reference optical path signal and the test optical path signal on two rows of pixel points with a certain distance. By comparing the pixel point information of the two rows of signals, the influence of background noise in the test signal can be weakened, and the detection limit of the system can be improved. The simulated optical trace is as Figure 5 shown. The point array with a resolution of 0.8 nm at 900 nm is as Figure 6 shown, verifying the excellent performance advantages of high resolution and low noise of the fiber-optic miniaturized Raman spectrometer designed in this embodiment.

[0077] The fiber - type miniaturized Raman spectrometer designed in this embodiment has the advantages of miniaturization, high precision, wide detection range and low cost. It is applicable to practical scenarios such as quality inspection, clinical / in - vivo sample analysis, and fermentation monitoring, and has a wide range of application scenarios.

[0078] In terms of quality inspection, the fiber - type miniaturized Raman spectrometer designed in this embodiment can provide rapid and accurate analysis of the substance composition, which helps to improve the quality control level of products. For example, in the pharmaceutical industry, the Raman spectrometer can be used for quantitative analysis of drug components and quality inspection of raw materials, improving production efficiency and reducing the risk of unqualified products. In clinical or in - vivo sample analysis, it can be used to non - invasively obtain the chemical composition information of biological tissues, providing important data for disease diagnosis and treatment. In the field of fermentation monitoring, it can monitor the biomass and metabolites in the fermentation process in real - time, optimize the fermentation process, and improve production efficiency.

[0079] The portability of the fiber - type miniaturized Raman spectrometer designed in this embodiment also makes it suitable for rapid detection in the field and on - site applications, such as environmental monitoring and food safety detection. In environmental monitoring, it can detect unknown sealed liquid or solid potentially dangerous chemicals on - site, quickly obtain the basic information of the substance before the laboratory analysis results are confirmed, ensuring the safety of operation and achieving rapid and accurate identification. In food safety detection, it can quickly detect harmful substances such as additives and pesticide residues in food, protecting the health of consumers.

[0080] In summary, the advantages of the fiber - type miniaturized Raman spectrometer designed in this embodiment, such as miniaturization, high precision, wide detection range and low cost, enable it to meet the requirements of different industries for precise, rapid and portable analysis.

[0081] The above - described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path, characterized in that: include: Laser module, used to provide multi-channel excitation light source; A collection module is used to collect multiple excitation light sources onto one optical fiber; A beam splitting module, used to split the collected excitation light source according to a preset ratio to obtain a first excitation light source and a second excitation light source; A Raman scattered light generation module, used to input the first excitation light source into a reference channel to generate a first Raman scattered light, and input the second excitation light source into a sample detection channel to generate a second Raman scattered light, wherein the reference channel is used to provide a reference sample, and the sample detection channel is used to provide a sample to be tested; A Raman scattered light filtering module, used for filtering the first Raman scattered light and the second Raman scattered light respectively; A Raman scattered light collimation module, used for collimating the filtered first Raman scattered light and the second Raman scattered light; The Raman scattered light detection module is used to simultaneously perform spectral detection on the collimated first Raman scattered light and the second Raman scattered light, and output the detection result.

2. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to claim 1, characterized in that: The laser module includes a plurality of lasers, and the lasers are used to provide excitation light sources with different wavelengths.

3. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to claim 1, characterized in that: The aggregation module includes any one of a wavelength division multiplexer and a beam combiner, and the wavelength division multiplexer and the beam combiner are used to combine the output optical fibers of multiple lasers into a single optical fiber.

4. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to claim 1, characterized in that: The beam splitting module comprises a fiber beam splitter, and the fiber beam splitter is used to distribute the excitation light source to the reference channel and the sample detection channel according to a preset ratio.

5. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to claim 1, characterized in that: The Raman scattered light generation module includes a first optical fiber circulator and a second optical fiber circulator, wherein the first optical fiber circulator is used to provide unidirectional transmission for the first excitation light source and the first Raman scattered light respectively; the second optical fiber circulator is used to provide unidirectional transmission for the second excitation light source and the second Raman scattered light respectively.

6. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to claim 1, characterized in that: The Raman scattered light collimation module comprises a first collimator and a second collimator, wherein the first collimator is used to collimate the filtered first Raman scattered light into a first parallel light; and the second collimator is used to collimate the filtered second Raman scattered light into a second parallel light.

7. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to claim 1, characterized in that: The Raman scattered light detection module includes a dispersive element, a lens and a detector connected in sequence. Parallel light is input into the dispersive element for dispersion and spectroscopy, and then the lens is used to focus the signals of the reference channel and the sample detection channel on two rows of pixels of the detector.

8. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to any one of claims 1 to 7, characterized in that: The Raman scattered light filtering module includes a first optical fiber bandpass filter and a second optical fiber bandpass filter, wherein the first optical fiber bandpass filter is used to filter the first Raman scattered light to obtain the first Raman scattered light longer than the laser output wavelength; the second optical fiber bandpass filter is used to filter the second Raman scattered light to obtain the second Raman scattered light longer than the laser output wavelength.

9. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to any one of claims 1 to 7, characterized in that: The Raman scattered light filtering module comprises a long pass filter, and the long pass filter is used to filter the first Raman scattered light and the second Raman scattered light to obtain the first Raman scattered light and the second Raman scattered light that are longer than the output wavelength of the laser.

10. The fiber-optic integrated dispersive Raman spectrometer with a built-in reference optical path according to any one of claims 1 to 7, characterized in that: The Raman scattered light filtering module includes a first notch filter and a second notch filter, wherein the first notch filter and the second notch filter are used to reflect the first excitation light source, the second excitation light source, and Rayleigh scattered light, and the first notch filter and the second notch filter both include an optical switch, a fiber Bragg grating, and a combiner connected in sequence, wherein n fiber Bragg gratings are connected in parallel.

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