Multi-mode microscopic Raman spectrum detection system

Abstract

The invention discloses a multi-mode microscopic Raman spectrum detection system, which comprises a white light microscopic imaging module, a reflection type Raman spectrum excitation and detection module, a transmission type Raman spectrum excitation and detection module, an optical information excitation module and an optical guiding module. Light path integration of all the modules is realized by sharing a microscope objective, image acquisition, reflection Raman detection and transmission Raman detection of a sample can be completed on the same platform, and the device has the advantages of high spatial alignment, flexible operation switching and adaptability to detection of multiple types of samples, and is suitable for micro-area Raman analysis in the fields of biomedicine, material science and the like.

Description

Technical Field

[0001] This invention relates to the field of spectral analysis technology, specifically to a multi-mode micro Raman spectroscopy detection system, belonging to the interdisciplinary field of integrated optical detection equipment and its applications. It is particularly suitable for applications in biological samples, material characterization, drug detection, and other fields that require non-destructive, multi-angle, and refined analysis of micro-area components. Background Technology

[0002] Raman spectroscopy is a spectroscopic analysis method based on light scattering phenomena of molecular vibrations, rotations, and other low-frequency modes. Due to its specific ability to identify the molecular structure and composition of substances, it is widely used in materials analysis, chemical composition identification, and biological detection. At the microscopic scale, Raman spectroscopy, combined with high-resolution imaging technology, can achieve simultaneous observation of the sample's microstructure and molecular composition, meeting the needs for precise, non-destructive, and high-resolution analysis.

[0003] Traditional Raman detection systems often employ a reflective confocal optical path design, where the excitation light and Raman signal light are incident and collected from the same side of the sample. This configuration offers advantages such as compact structure and convenient alignment when processing thin-layer samples or performing surface analysis. However, when dealing with thick samples, strongly scattering media, or multilayer composite samples, interference from surface impurities, particle scattering, and interface reflections can easily lead to Raman signal intensity attenuation and a reduced signal-to-noise ratio, making it difficult to accurately reflect the internal composition information of the sample.

[0004] Transmission Raman spectroscopy, as an important supplement, involves excitation and signal light incident and collected from opposite sides of the sample, effectively avoiding interference from surface scattering and reflection. It is particularly suitable for extracting internal features from samples with complex structures, uneven internal composition, or significant optical thickness. However, this technique is less intuitive in spatial localization than reflection-based methods and lacks the ability to rapidly identify surface components.

[0005] Furthermore, Raman spectroscopy alone is often insufficient to comprehensively characterize a sample's macroscopic morphology, local composition, and deep structure. Therefore, a recent research trend has emerged combining Raman spectroscopy with white light microscopy, utilizing microscopic images for spatial localization and morphology identification, and then combining Raman information for compositional analysis. However, existing systems are mostly modular structures, lacking a unified optical path integration design, and suffer from problems such as complex alignment, information asynchrony, and system redundancy.

[0006] In summary, how to construct a compact, switchable, and highly integrated multimodal Raman detection system to simultaneously achieve three functions—white light microscopy, reflective Raman detection, and transmissive Raman detection—and simplify the optical path alignment and switching mechanism through coaxial or split-path modular design, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] To overcome the shortcomings of existing Raman detection technologies in terms of spatial positioning accuracy, deep signal extraction capability, and optical path integration, this invention proposes a multi-mode micro-Raman spectroscopy detection system with high structural integration, strong functional complementarity, and applicability to various sample types. This system integrates three types of optical modules: white light microscopy imaging, reflection Raman detection, and transmission Raman detection. Combined with a unified optical guidance structure and a coaxial / splitter switching mechanism, it can achieve both macroscopic structural observation of samples and molecular composition analysis of both surface and deep layers, thus meeting the comprehensive detection needs of complex samples in terms of microstructure and component identification. The structural composition and functional implementation of this system are further explained below with reference to specific embodiments of the invention.

[0008] In one embodiment of the present invention, a multi-mode micro-Raman spectroscopy detection system is provided, comprising: a white light microscopic imaging module, a reflective Raman spectroscopy excitation module, a reflective Raman spectroscopy detection module, an optical information excitation module, a transmission Raman spectroscopy excitation module, a transmission Raman spectroscopy detection module, and an optical guidance module. The white light microscopy imaging module provides a white light illumination source and acquires white light microscopic images; the reflective Raman spectroscopy excitation module provides a continuous laser source to excite the reflective Raman spectrum of the sample; the reflective Raman spectroscopy detection module detects the reflected Raman spectral signal of the excited sample; the optical information excitation module focuses the excitation light onto the sample and collects the Raman spectral signal of the sample; the transmission Raman spectroscopy excitation module provides a continuous laser source to excite the transmission Raman spectrum of the sample; the transmission Raman spectroscopy detection module detects the transmission Raman spectral signal of the excited sample; and the optical guidance module guides and separates the excitation light and signal light from different modules to achieve coaxial convergence or optical path separation of the white light illumination light, the reflective Raman spectroscopy excitation and detection light, and the transmission Raman spectroscopy excitation and detection light among different modules.

[0009] Furthermore, the white light microscopy imaging module includes: an LED light source, a collimator, a beam expander lens group, a first beam splitter, an imaging lens, and a CCD camera. The illumination light emitted by the LED light source is collimated by the collimator and expanded by the beam expander lens group, then transmitted through the first beam splitter to the optical information excitation module and illuminates the sample; the white light imaging signal light reflected from the sample returns through the optical information excitation module, is reflected by the first beam splitter, and converged by the imaging lens to the CCD camera, thereby realizing the acquisition of a white light microscopic image.

[0010] Preferably, the reflective Raman spectroscopy excitation module includes: a first fiber-coupled, continuously adjustable power 785nm laser, a first fiber collimator, and a first bandpass filter. The 785nm laser emitted by the laser is collimated by the first fiber collimator and stray light is filtered out by the first bandpass filter before being guided into the optical guidance module.

[0011] Furthermore, the reflection Raman spectroscopy detection module includes: a first long-pass filter, a first collecting lens, a pinhole, a second collimating lens, a second imaging lens, a first fiber optic coupler, and a first Raman spectrometer. The reflected Raman signal light excited by the sample is transmitted sequentially through the optical information excitation module and the optical guidance module. First, the elastic scattered light is filtered out by the first long-pass filter, then collected by the first collecting lens and focused onto the pinhole for spatial filtering. Subsequently, it is collimated by the second collimating lens and focused again by the second imaging lens, finally coupled into the first fiber optic coupler and transmitted to the first Raman spectrometer for signal acquisition.

[0012] Preferably, the optical information excitation module is a microscope objective, used to focus the illumination light and / or reflected Raman spectral excitation light from the white light microscopy imaging module onto the sample, and collect the white light signal and / or Raman scattering signal returned by the sample.

[0013] Furthermore, the transmission-type Raman spectroscopy excitation module includes: a second fiber-coupled continuously adjustable power 785nm laser, a second fiber collimator, a second bandpass filter, a converging lens, and a one-dimensional moving platform. The 785nm laser output from the second laser is collimated by the second fiber collimator and filtered by the second bandpass filter, and then focused onto the sample by the converging lens; the one-dimensional moving platform is used to support and adjust the position of the converging lens or its components to change the focusing position of the excitation light in the sample.

[0014] Preferably, the transmission Raman spectroscopy detection module includes: a second long-pass filter, a third collecting lens, a second fiber optic coupler, and a second Raman spectrometer. The transmitted Raman signal light generated by the sample is filtered out by the second long-pass filter to remove elastic scattered light, then collected and focused by the third collecting lens, and finally coupled into the second fiber optic coupler and transmitted to the second Raman spectrometer for signal analysis.

[0015] Furthermore, the optical guiding module includes a reflector, a second beam splitter, a dichroic mirror, and a third beam splitter. The reflector reflects the laser light from the reflective Raman spectroscopy excitation module to the second beam splitter; the second beam splitter is located in the optical path of the white light microscopy imaging module and guides the laser light reflected by the reflector to the dichroic mirror, while transmitting white light illumination light from the white light microscopy imaging module; the dichroic mirror is located at the optical path entrance of the optical information excitation module and reflects excitation light with a wavelength less than or equal to 785 nm and transmits Raman signal light with a wavelength greater than 785 nm; the third beam splitter is positioned on the Raman signal light transmission path and transmits the reflected Raman signal light to the reflective Raman spectroscopy detection module, while reflecting the transmitted Raman signal light to the transmission Raman spectroscopy detection module.

[0016] Optionally, the pinhole is located at the focal point of the first collecting lens to achieve the confocal function of reflective Raman spectroscopy detection, thereby improving the system's spatial resolution and signal-to-noise ratio.

[0017] Optionally, the one-dimensional moving platform is an X-axis moving platform, which can realize precise lateral adjustment of the transmission excitation spot on the sample, making it easy to control the laser focus position and adapt to the detection needs of samples of different sizes and structures.

[0018] Based on the above technical solution, the multi-mode micro Raman spectroscopy detection system of the present invention integrates a white light microscopic imaging module, a reflection Raman spectroscopy detection module, and a transmission Raman spectroscopy detection module, and realizes coaxial or split-path control of the optical path at the optical guidance module. This solves the problem that existing single Raman detection methods cannot simultaneously take into account imaging positioning and multi-layer structure analysis, and significantly improves the system's detection capability and signal-to-noise ratio for samples in multiple dimensions such as macroscopic morphology, surface composition, and deep structure.

[0019] The white light microscopy imaging module of this invention uses a high-brightness LED light source and a high-resolution CCD image acquisition unit, which can realize rapid observation and positioning of sample morphology, providing a spatial positioning basis for subsequent Raman detection; through optical path collimation and beam expansion design, the imaging clarity and illumination uniformity are improved.

[0020] The system flexibly switches between a reflection Raman spectroscopy module and a transmission Raman spectroscopy module through an adjustable optical path combination. The former is suitable for acquiring Raman information from the sample surface and shallow layers, while the latter is particularly suitable for analyzing the deep composition and structure of thick samples, non-transparent materials, or strongly scattering samples. The two modules complement each other in their detection capabilities. Parallel acquisition via a dual-channel Raman spectrometer improves detection efficiency and data integrity.

[0021] The optical information excitation module in the system is a high numerical aperture microscope objective, which can be used to converge excitation light to achieve high-density energy focusing, and can also be used to efficiently collect Raman scattering signals. Combined with the confocal pinhole structure, it can provide good performance in terms of spatial resolution and background suppression, and is particularly suitable for fine identification of micro-area sample components.

[0022] The reflectors, beam splitters, and dichroic mirrors in the optical guidance module are configured according to their functions, realizing unified path management of multiple light sources (LED, 785nm laser) and multi-channel signal light (white light reflection, Raman scattering), ensuring the system's compactness and ease of operation. At the same time, it enables the spatial overlap or separation of the three types of optical paths—illumination, excitation, and detection—at a single objective lens, simplifying the alignment process and improving detection accuracy.

[0023] Overall, the multi-mode micro Raman spectroscopy detection system constructed in this invention has the following significant advantages: 1. Multimodal collaborative detection: The system integrates white light imaging and two Raman detection modes, enabling full-process detection from "localization to shallow analysis to deep detection"; 2. Highly integrated structure: All modules are integrated into one unit through a unified optical guidance structure, resulting in a compact size and easy installation and maintenance; 3. Flexible optical path switching: The coaxial / splitter structure design enables rapid switching between different detection modes, reducing manual intervention; 4. Wide range of sample compatibility: The system is compatible with various sample types such as thin films, biological tissues, particles, and composite materials, making it suitable for scientific research, materials analysis, drug screening, and other fields. 5. High signal acquisition stability: The Raman detection channel is equipped with filtering, collimation, focusing and coupling systems, which effectively improves the signal-to-noise ratio and data reliability.

[0024] In summary, this invention, by constructing a multi-mode Raman spectroscopy detection system, fully leverages the advantages of various optical detection technologies, enabling multi-angle, multi-scale, and high-precision simultaneous observation of sample structure, morphology, and molecular composition. This provides technical support for rapid, accurate, and non-destructive testing of complex samples and has broad application prospects and industrialization value. Attached Figure Description

[0025] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the embodiments of the present invention are briefly described below. The drawings are only used to illustrate the structural principle of the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0026] Figure 1 This is a schematic diagram of the overall structure of the multi-mode micro Raman spectroscopy detection system described in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the white light microscopy imaging module in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the reflection Raman spectroscopy detection module in an embodiment of the present invention; Figure 4 This is a schematic diagram of the transmission Raman spectroscopy detection module in an embodiment of the present invention.

[0027] The labels in the diagram are explained as follows: System modules: 1 is the reflection Raman spectroscopy excitation module, 2 is the white light microscopy imaging module, 3 is the optical guidance module, 4 is the optical information excitation module, 5 is the transmission Raman spectroscopy excitation module, 6 is the reflection Raman spectroscopy detection module, and 7 is the transmission Raman spectroscopy detection module.

[0028] Reflection Raman spectroscopy excitation module: 101 is a 785nm laser, 102 is a fiber collimator, and 103 is a 785nm bandpass filter.

[0029] White light microscopy module: 21 is an LED light source, 22 is a collimator, 23 and 24 are aspherical lenses, 25 is a dichroic mirror, 26 is a plane mirror, 27 is an imaging lens, and 28 is a CCD camera.

[0030] Optical guidance module: 31 is a reflecting mirror, 32 is the first beam splitter, 33 is a dichroic mirror, and 34 is the second beam splitter.

[0031] Transmission Raman spectroscopy excitation module: 51 is an achromatic cemented doublet lens, 52 is a 785nm bandpass filter, 53 is an fiber collimator, 54 is a 785nm laser, and 55 is an X-axis TSD moving platform.

[0032] Reflection Raman spectroscopy detection module: 61 is a 785nm long-pass filter, 62 is a cemented doublet achromatic lens, 63 is a reflecting mirror, 64 is a pinhole, 65 is an aspherical lens, 66 is an imaging lens, 67 is a fiber optic coupler, and 68 is a Raman spectrometer.

[0033] Transmission Raman spectroscopy detection module: 71 is a 785nm long-pass filter, 72 is an imaging lens, 73 is a fiber optic coupler, and 74 is a Raman spectrometer. Detailed Implementation

[0034] To make the technical solution and beneficial effects of the present invention clearer and more explicit, the multi-mode micro Raman spectroscopy detection system of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments described are for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0035] The directional terms described in this specification, such as "up," "down," "left," "right," "front," and "rear," are defined with reference to the directions shown in the accompanying drawings for ease of description only and do not constitute a limitation on the present invention. Similarly, the component numbers and drawing numbers mentioned herein are for illustrative purposes only, and the scope of protection should be determined by the claims.

[0036] Those skilled in the art, after reading this specification, should understand that various modifications or equivalent substitutions can be made without departing from the core concept of this invention, and such modifications and substitutions should be considered to fall within the protection scope of this invention.

[0037] Example 1: System Overall Structure and Module Composition In one embodiment of the present invention, such as Figure 1 As shown, a multi-mode microscopic Raman spectroscopy detection system includes: a white light microscopic imaging module 2, a reflection Raman spectroscopy excitation module 1, a reflection Raman spectroscopy detection module 6, a transmission Raman spectroscopy excitation module 5, a transmission Raman spectroscopy detection module 7, an optical information excitation module 4, and an optical guidance module 3. All of these functional modules are mounted on a unified optical platform and integrated and aligned using precision displacement components, standard optical supports, and connectors to form an integrated, highly stable multi-mode Raman detection system.

[0038] The white light microscopy imaging module 2 provides visible light illumination and acquires microscopic image information of the sample. The reflection-type Raman spectroscopy excitation module 1 and the transmission-type Raman spectroscopy excitation module 5 provide 785nm laser excitation sources from the upper and lower sides of the sample, respectively; the reflection-type Raman spectroscopy detection module 6 and the transmission-type Raman spectroscopy detection module 7 acquire Raman scattering signals from corresponding directions. The optical information excitation module 4 is located at the core of the system's optical path, serving as a converging and channel-sharing component for the excitation and signal lights. It is preferably a high numerical aperture microscope objective, used to focus the beam and collect signals from the sample. The optical guidance module 3 coordinates and guides the propagation paths of the various beams, ensuring that the white light illumination path, Raman excitation path, and Raman signal path are spatially coaxially integrated or spatially separated.

[0039] Furthermore, both the excitation and detection light paths in the system undergo wavelength selective allocation and path adjustment via multiple reflecting mirrors 31, a first beam splitter 32, a dichroic mirror 33, and a second beam splitter 34 within the optical guidance module 3. This ensures that beams from different sources spatially overlap before entering the optical information excitation module 4, while the returning signal light is further separated and guided to the corresponding detection modules 6 and 7 based on its wavelength and propagation direction. This design significantly simplifies the alignment complexity in multi-path structure systems and achieves the synergistic fusion of three modes—white light imaging, reflective Raman detection, and transmission Raman detection—within a single objective lens.

[0040] Preferably, all optical components of the system are mechanically fixed and optically collimated using SM1 standard interfaces or custom-made components. During installation, each sub-module can be independently fine-tuned using a high-precision three-dimensional adjustment bracket, thereby ensuring that the optical axis coincidence accuracy of different optical paths within ±1μm at the front end of objective lens 4, and ensuring that the image acquisition point is consistent with the Raman spectrum acquisition point.

[0041] The system structure described in this embodiment lays the hardware foundation for the implementation of multimodal detection. The specific structure and optical path implementation of each functional module will be described in detail in the following embodiments.

[0042] Example 2: System Operation Flow and Multi-Mode Detection Sequence Explanation In one embodiment of the present invention, based on Figure 1 The multi-mode micro-Raman spectroscopy detection system shown allows users to sequentially complete white light image acquisition, reflection Raman spectroscopy acquisition, and transmission Raman spectroscopy acquisition on a single platform, forming a continuous, closed-loop multi-mode analysis workflow. This workflow is suitable for combined detection scenarios involving sample structure localization, surface molecule detection, and deep component analysis, and specifically includes the following steps: Step 1: White light microscopy image acquisition When the LED light source 21 in the white light microscopy imaging module is turned on, the illumination light emitted by it is collimated by the collimator 22 in sequence, and then expanded and shaped by the beam expanding lens group composed of two aspherical lenses 23 and 24. It is then transmitted to the microscope objective 4 through the first beam splitter 25, the second beam splitter 32 in the optical guidance module and the dichroic mirror 33, and finally illuminates the sample surface.

[0043] The image signal reflected from the sample is transmitted back through the microscope objective, reflected by the dichroic mirror 33 to the first beam splitter 25, and finally focused by the imaging lens 26 onto the CCD camera 28 to form a clear image. Users can observe the sample morphology, locate the detection area, and adjust the focus through the image interface, providing a spatial reference for Raman detection.

[0044] Step 2: Reflection Raman Spectroscopy Acquisition Turn off the white light source and start the 785nm laser 101 in the reflection Raman spectroscopy excitation module 1. The laser beam is collimated and expanded by the fiber collimator 102, and after being purified by the bandpass filter 103, it is guided by the reflector 31 to the second beam splitter 32, and then reflected by the dichroic mirror 33 into the microscope objective 4, where it is focused onto the sample surface to excite Raman scattering.

[0045] The Raman signal is transmitted in reverse along the incident path, passing sequentially through the microscope objective 4 and the dichroic mirror 33 to the second beam splitter 34. A portion of the signal is transmitted to the reflective Raman detection module 6, and then sequentially through the long-pass filter 61, the collecting lens 62, the pinhole 64, the collimating lens 65, the imaging lens 66, and the fiber optic coupler 67 to the Raman spectrometer 68 for spectral analysis.

[0046] This step enables high-resolution Raman detection of the sample surface and shallow layers, and is suitable for molecular recognition of samples such as particulate matter, tissue surface, and membrane materials.

[0047] Step 3: Transmission Raman Spectroscopy Acquisition While keeping the sample position unchanged, the laser 54 in the transmission Raman spectroscopy excitation module 5 is activated. The 785nm laser beam emitted by the laser is shaped by the collimator 53 and filtered by the bandpass filter 52. Then, it is focused by the focusing lens (51) to the bottom of the sample, thus realizing the excitation path from bottom to top.

[0048] The Raman signal is transmitted from the bottom of the sample and received by the transmission Raman spectroscopy detection module 7 below. It then passes sequentially through a 785nm long-pass filter 71, a collecting lens 72, and a fiber optic coupler 73 before entering the spectrometer (74) for analysis and acquisition. This path is suitable for thick samples, layered materials, or samples with strong scattering properties, and can effectively obtain the Raman response of their internal structure.

[0049] In actual operation, the focusing lens 51 is mounted on the X-axis TSD platform 55. The position of the laser incident point and the excitation depth can be precisely controlled through the lateral adjustment function of the platform, so as to achieve flexible adaptation to samples of different thicknesses.

[0050] The three detection modes described above can be quickly switched manually between the light source and laser or via software control modules, depending on the system configuration. This avoids repeated adjustments to the sample or objective lens position, thus achieving fully automated, continuous, and multi-dimensional acquisition of spectral and image information. The entire process can be completed within a unified operating platform, improving detection efficiency and data consistency.

[0051] Example 3: Structure and function of white light microscopy imaging module ( Figure 2 ) In one embodiment of the present invention, such as Figure 2As shown, the white light microscopy imaging module 2 mainly includes: an LED light source 21, a collimator 22, two aspherical lenses 23 and 24, a first beam splitter 25, a plane mirror 26, an imaging lens 27, and a CCD camera 28, which are used to provide visible light illumination for the sample and acquire its reflected images to achieve precise positioning and structural observation.

[0052] Specifically, the LED light source 21 is a high-brightness white point light source, installed at the initial position of the module, used to generate uniform and stable visible light illumination. Its output beam first enters the collimator 22, which is composed of multi-layer coated lenses, capable of collimating the diverging beam into parallel light, improving the illumination directionality and light intensity utilization efficiency.

[0053] The collimated beam passes sequentially through a beam-expanding lens group consisting of aspherical lens 23 and aspherical lens 24, undergoing beam expansion to increase the beam coverage area and make the illumination range more uniform. This lens group adopts a low chromatic aberration design, which can effectively reduce imaging distortion.

[0054] The expanded white illumination beam continues to travel forward and is transmitted through the first beam splitter 25 into the common optical path. Preferably, this beam splitter is a near-infrared broadband transmission type that transmits visible light and is compatible with the laser reflection channel. It is then positioned in the paths of the optical guidance module 3 and the optical information excitation module 4, and finally illuminates the surface of the sample to be tested.

[0055] Under the influence of the white light reflected from the sample, the returned microscopic image signal light propagates in reverse along the original path. After passing through the optical information excitation module 4, it is reflected 90 degrees by the first beam splitter 25, and then turned again by the plane mirror 26. Finally, it enters the imaging lens 27, which focuses and converges the light signal onto the photosensitive surface of the CCD camera 28.

[0056] The imaging lens 27 is a multi-layer cemented achromatic design that can simultaneously focus light of different wavelengths, effectively improving image clarity and resolution; the CCD camera 28 is a high-sensitivity industrial-grade imaging device that supports functions such as image enhancement and exposure time adjustment, and can acquire high-resolution white light microscopic images in real time.

[0057] Furthermore, all optical components in the white light microscopy module are mounted on a unified module bracket via standard SM1 threaded tubes, precision optical rails, and custom-machined connectors. The spacing and angles of each component can be finely adjusted during installation to achieve optimal optical axis alignment and matching with the image focal plane.

[0058] With the above structural configuration, the white light microscopy imaging module can achieve clear imaging of the sample's microstructure, providing key image references for target area localization and feature selection in Raman detection, and effectively improving detection efficiency and result reliability.

[0059] Example 4: Reflection Raman Spectroscopy Excitation Module ( Figure 1 Middle component 1) In one embodiment of the present invention, such as Figure 1 As shown, the reflective Raman spectroscopy excitation module 1 is used to provide a stable Raman excitation source for the sample surface, forming the incident port for Raman spectroscopy detection. This module mainly includes: a 785nm fiber-coupled continuously variable power laser 101, a fiber collimator 102, and a 785nm bandpass filter 103.

[0060] The laser 101 is a near-infrared semiconductor laser with a center wavelength of 785nm, featuring continuous power output capability and an adjustable output power range, typically from 10mW to 300mW. The laser employs a fiber-coupled output structure, with a single-mode fiber connector integrated at its front end, facilitating decoupling and installation from the optical system, thus improving stability and modularity.

[0061] The 785nm laser output from the laser is first collimated by an optical fiber collimator 102. The collimator is packaged with a high-precision aspherical collimating lens group and has a low divergence angle (typical value <1mrad), which can convert the outgoing beam into collimated parallel light, facilitating subsequent filtering and guidance.

[0062] Furthermore, to ensure the purity of the excitation spectrum and reduce interference from stray light and laser sidebands, the collimated beam is filtered by a 785nm bandpass filter 103. This filter uses a high-transmittance dielectric coating material, has a narrow bandwidth (center wavelength 785±2nm, bandwidth FWHM≤5nm), and steep edges, which can effectively filter out spontaneous emission, ASE noise, and other non-Raman related components emitted by the laser, thereby improving the monochromaticity of the excitation light.

[0063] The filtered, collimated laser beam is guided into the optical guidance module 3, specifically reflected by the reflector 31 to the first beam splitter 32, and then guided by the dichroic mirror 33 to the microscope objective at the optical information excitation module 4, achieving precise focused illumination of the sample. This path design ensures that the excitation light and the white illumination light can be transmitted coaxially, which is beneficial for the subsequent spatial synchronous acquisition of Raman signals and image data.

[0064] Preferably, to improve system adaptability and safety, the laser 101 can integrate a power regulation controller, supporting output power adjustment via analog voltage or digital interface, and is equipped with a temperature stabilization unit (TEC) and current drive protection circuit to achieve stable output over a long period. Furthermore, a laser safety shield can be added to the outside of the module, and a laser interlocking mechanism can be set up to ensure operator safety.

[0065] Through the above structural design and performance configuration, the reflective Raman spectroscopy excitation module can provide a stable and high-purity excitation source for the sample, meeting the stringent requirements of high-sensitivity Raman spectroscopy acquisition for excitation wavelength stability, power controllability, and beam quality. It is one of the key components for achieving efficient reflective Raman excitation in the system of this invention.

[0066] Example 5: Reflection Raman Spectroscopy Detection Module ( Figure 3 ) In one embodiment of the present invention, such as Figure 3 As shown, the reflective Raman spectroscopy detection module 6 is used to collect the reflective Raman scattering signal generated by the sample under laser excitation. This module includes: a 785nm long-pass filter 61, a cemented doublet achromatic collecting lens 62, a mirror 63, a pinhole 64, an aspherical collimating lens 65, an imaging lens 66, a fiber optic coupler 67, and a Raman spectrometer 68. These components sequentially constitute the signal light transmission and processing link.

[0067] Specifically, the Raman scattering signal generated after the sample surface is excited enters the optical guidance module 3 through the optical information excitation module 4, and is transmitted to the detection module after being transmitted through the dichroic mirror 33 and split by the third beam splitter 34. At the beginning of the incident path, the signal light first passes through the 785nm long-pass filter 61, which is used to efficiently filter out the elastic scattered light (Rayleigh scattering) contained in the sample reflection, allowing only Raman signals with wavelengths greater than 785nm to pass through, thereby improving the purity and signal-to-noise ratio of the subsequent signal.

[0068] The Raman signal light passing through the filter is collected by a cemented doublet achromatic lens 62, which has a large numerical aperture and chromatic aberration correction capability, enabling efficient focusing of the signal to the focal point. To further suppress background noise and improve spatial resolution, the beam is focused at a pinhole 64, which is located on the focal plane of the collecting lens 62, achieving spatial filtering and allowing only the signal light from the focal region to pass through, thus constructing a confocal detection system. This confocal structure can effectively suppress interference light from off-focal planes (such as sample background or surface stray areas), improving the spatial accuracy and Raman signal intensity ratio of the detection.

[0069] After passing through the pinhole, the Raman signal beam is collimated by the aspherical lens 65 and then enters the imaging lens 66, forming a spot size and pattern suitable for fiber coupling. This part of the optical path completes the conversion from free space propagation to fiber incident. Subsequently, the signal light is received by the fiber coupling mirror 67 and efficiently coupled into a single-mode or multimode fiber, and then guided through the fiber to the Raman spectrometer 68 for spectral signal analysis and recording.

[0070] Preferably, the Raman spectrometer 68 is a high-resolution, high-sensitivity multi-channel detection device with functions such as wavelength range covering 200~2000cm⁻¹, adjustable integration time, and temperature-controlled detection chip, which is suitable for Raman qualitative and quantitative analysis in multiple fields such as biology, materials, and pharmaceuticals.

[0071] Furthermore, the pinhole size can be selected from typical apertures between 25 and 100 μm according to actual detection requirements, balancing spatial resolution and signal strength. During system debugging, the optimal focus matching is achieved by fine-tuning the positional relationship between the lens and the pinhole, ensuring maximum Raman signal transmittance.

[0072] In summary, the aforementioned reflection Raman spectroscopy detection module, through a multi-stage structure including long-pass filtering, spatial confocalization, collimation focusing, and fiber coupling, constructs a stable, efficient, and low-noise Raman signal acquisition link, making it a key module for achieving high-quality reflection Raman detection.

[0073] Example 6: Transmission Raman Spectroscopy Excitation Module ( Figure 1 Component 5) In one embodiment of the present invention, such as Figure 1 As shown, the transmission Raman spectroscopy excitation module 5 is used to provide excitation light from below the sample to achieve transmission Raman detection, which is particularly suitable for deep excitation of thick samples, multilayered samples, or strongly scattering samples. This module includes: a 785nm fiber-coupled continuously variable power laser (54), a fiber collimator 53, a 785nm bandpass filter 52, an achromatic cemented doublet lens 51, and an X-axis TSD moving platform 55.

[0074] Specifically, the laser 54 is a semiconductor laser with a center wavelength of 785nm, featuring a continuous output mode and adjustable output power, typically ranging from 10 to 300mW. This laser is connected to an optical fiber collimator 53 via an optical fiber output. The collimator is used to collimate the emitted laser beam into parallel light, ensuring the stability and consistency of the subsequent beam transmission path.

[0075] The collimated laser beam is further passed through a 785nm bandpass filter 52 to filter out stray light and sideband components emitted by the laser, retaining only the excitation light at the center wavelength, thereby improving laser monochromaticity and system background suppression capabilities. The filter uses a high-transmittance dielectric film structure, with a typical transmittance >95% and a bandwidth controlled within ±2nm.

[0076] The filtered laser beam is focused by an achromatic cemented doublet lens 51 to form a focused beam that illuminates the bottom of the sample being tested. This lens employs a composite optical design, effectively reducing the effects of chromatic aberration and spherical aberration, ensuring the focusing accuracy of the laser beam within the sample. This excitation path, together with the reflective Raman excitation path, forms an opposing structure, with the excitation light incident from the bottom of the sample. This places the excitation point inside the sample rather than on the surface, significantly improving the availability of deep Raman signals.

[0077] Furthermore, to achieve precise adjustment of the laser focus along the sample thickness direction, the focusing lens 51 is fixed to the X-axis TSD platform 55 via a mounting bracket. This platform has a high-precision lateral movement function, which can finely adjust the position of the focusing lens along the X-axis direction, changing the lateral projection point or focal depth of the laser in the sample to adapt to samples of different thicknesses and complex structures, thus achieving regionally controllable excitation.

[0078] Preferably, the X-axis TSD platform 55 is a micron-level electric displacement platform with a travel range of ±10mm and a minimum resolution of 1μm. It can be controlled by a stepper motor or a spiral fine-tuning mechanism and is compatible with automated scanning functions.

[0079] In summary, the transmission Raman spectroscopy excitation module adopts a bottom-up laser incident path, combined with a high-quality beam shaping and precise displacement adjustment device. This not only effectively avoids surface strays and absorption interference, but also allows for flexible setting of the excitation position according to the actual sample structure requirements. It is an important supporting unit for the realization of deep non-destructive Raman detection in this invention.

[0080] Example 7: Transmission Raman Spectroscopy Detection Module ( Figure 4 ) In one embodiment of the present invention, such as Figure 4 As shown, the transmission Raman spectroscopy detection module 7 is used to collect the Raman scattering signal emitted from the bottom of the sample under transmission excitation, complementing the reflection detection channel to form a symmetrical Raman information acquisition system. This module mainly includes: a 785nm long-pass filter 71, an achromatic cemented doublet collecting lens 72, a fiber optic coupler 73, and a Raman spectrometer 74.

[0081] Specifically, in the transmission Raman detection mode, after the laser is transmitted and excited from the bottom of the sample, the Raman scattering signal generated inside the sample continues to be emitted downward along the original propagation direction. This signal light first passes through a 785nm long-pass filter 71 set at the beginning of the detection path. This filter is used to effectively filter out residual elastic scattering (such as Rayleigh scattering) in the excitation light, retaining only the redshifted Raman signal, thereby improving the spectral purity of the signal and the detection efficiency of the spectrometer.

[0082] The filtered Raman signal light is then collected by an achromatic cemented doublet lens 72. This lens has a large numerical aperture and chromatic aberration correction capability, effectively focusing the weak signal light from below the sample, reducing optical path loss, and enhancing coupling efficiency. The position of this lens is axially symmetrical with the laser focusing point below the transmission Raman excitation module 5, ensuring optimal acquisition of the transmission Raman signal.

[0083] The collected signal light continues to enter the fiber optic coupler 73, which focuses the beam onto the fiber end face and connects it to the Raman spectrometer 74 via a multimode or single-mode fiber. The fiber optic coupler has the function of adjusting the position and size of the light spot, enabling high-efficiency coupling and ensuring signal transmission stability. Preferably, the fiber optic coupler is mounted on a three-dimensional precision adjustment frame to accommodate different focal lengths and fine-tuning requirements of the optical axis.

[0084] The Raman Spectrometer 74 is a fully automated multi-channel Raman analysis system with high sensitivity and high resolution, suitable for high-precision analysis of weak Raman signals acquired from the sample transmission path. This instrument can be configured with a cooled CCD detector, variable integration time control, and spectral correction functions to adapt to different signal intensity scenarios.

[0085] Furthermore, the detection module is installed entirely below the sample platform, forming a closed transmission path with the transmission Raman excitation module (5). Through this aligned excitation and detection layout along the upper and lower axes, efficient Raman detection of the internal structure of the sample, thick materials, or the underlying components of opaque samples can be achieved. Compared to reflection Raman detection, transmission detection has stronger penetration capabilities and advantages in extracting deeper information, making it particularly suitable for the analysis of samples with strong surface scattering or internal heterogeneous structures.

[0086] In summary, the transmission Raman spectroscopy detection module, through long-pass filtering, focused collection, fiber coupling, and spectral analysis, constructs a high-sensitivity, low-background deep Raman signal acquisition path. It is a key module of the system of this invention to achieve information complementarity and improve the overall detection depth and accuracy in multimodal Raman detection scenarios.

[0087] Example 8: Description of the optical information excitation module ( Figure 1 Component 4) In one embodiment of the present invention, such as Figure 1 As shown, the optical information excitation module 4 is located at the converging end between each excitation / detection optical path and the sample, and is the key optical interface for the system to achieve "coaxial incidence and coaxial collection" in multiple modes. This module preferably uses a high numerical aperture microscope objective as its core component, which has high focusing capability and signal collection efficiency, and is used to achieve unified spatial path control of white light illumination, laser excitation and Raman scattering signals.

[0088] Specifically, the microscope objective is a dry microscope objective with a magnification of 50x and a numerical aperture (NA) of 0.75. This objective is suitable for the near-infrared band (covering 400–900 nm), has good light transmission performance and chromatic aberration correction capability, shallow depth of focus and high resolution, and is suitable for precise excitation and efficient collection of samples at the microscopic scale.

[0089] In white light microscopy imaging mode, the illumination light from LED light source 21 is expanded by collimator 22, aspherical lenses 23 and 24, transmitted through first beam splitter 25, guided by reflector 31, combined by second beam splitter 32, and transmitted through dichroic mirror 33 to the microscope objective 4. The objective focuses the illumination light onto the sample surface to achieve uniform illumination of the sample.

[0090] In Raman detection mode, whether in the reflection excitation (module 1) or transmission excitation (module 5) path, the laser passes through the reflecting mirror 31, beam splitter 32, and dichroic mirror 33 in the optical guidance module 3 before finally entering the microscope objective 4. This objective precisely focuses the excitation laser onto the target area of ​​the sample, achieving high energy density excitation, while maintaining the excitation point coincident with the image positioning point, thereby avoiding detection errors caused by focal deviation.

[0091] Whether the Raman scattering signal is reflected (returning from the upper surface of the sample) or transmitted (exiting from the lower surface of the sample), the signal light is collected by objective lens 4 and transmitted in the opposite direction in the reflection path, returning to the optical guidance module. Then, according to the wavelength, the path is separated by dichroic mirror 33 and second beam splitter 34, and guided to the corresponding Raman detection modules (6 or 7). In this way, the excitation light and scattered light form a "coaxial incident-coaxial collection" structure at the objective lens, which greatly improves the optical alignment accuracy and system stability.

[0092] Furthermore, to avoid cross-contamination between samples and lens contamination, a dust cover or laser window can be optionally fitted to the outside of the microscope objective. Depending on different detection needs, it can also be replaced with other magnifications (such as 20X, 100X), different working distances, or immersion objectives to adapt to detection scenarios with different resolutions, transmittances, or sample thicknesses.

[0093] In summary, the optical information excitation module, through the setting of a high-performance microscope objective, realizes a shared incident path for white light illumination and laser excitation light, and also serves as a unified collection channel for Raman signals. It is the core optical component of this invention for achieving coaxial optical path, compact structure, and precise acquisition of the multi-mode Raman system.

[0094] Example 9: Detailed Structure of the Optical Guiding Module ( Figure 1 Component 3) In one embodiment of the present invention, such as Figure 1As shown, the optical guidance module 3 is located between the white light microscopy imaging module 2, the reflective Raman spectroscopy excitation module 1, the optical information excitation module 4, and the Raman signal detection modules (6, 7). It is the core structural part of the entire system for realizing multimodal optical path beam combining and splitting. This module includes several key optical components, specifically: a reflecting mirror 31, a first beam splitter 32, a dichroic mirror 33, and a second beam splitter 34.

[0095] The reflector 31 is positioned in the reflective Raman excitation light path to reflect the 785nm laser beam output from the laser 101 at a 90-degree angle in space and guide it to the first beam splitter 32. The reflector uses a high-reflectivity dielectric coating material, covering a reflection band of 785nm ± 10nm, with a reflectivity greater than 99%, ensuring efficient energy transmission of the excitation light and precise control of the incident angle.

[0096] The first beam splitter 32 is located at the intersection of the white light illumination beam and the laser excitation beam. It is preferably a broadband composite beam splitter, which transmits white light in the 450–700 nm band and reflects laser light in the 750–800 nm band. When the white light emitted by the LED light source 21 reaches this point after collimation and beam expansion, it will be successfully transmitted to the dichroic mirror 33. The 785 nm laser beam emitted by the laser is reflected by the mirror 31 and enters this beam splitter. It will be reflected and guided to the same downstream path, achieving "coaxial beam combining" with the white light beam in space.

[0097] The dichroic mirror 33 is a key component of this guiding system, installed at the optical path interface before the optical information excitation module 4. It is preferably a high-performance excitation / Raman dichroic mirror, designed to reflect incident light with wavelengths below 785nm (such as 785nm excitation laser or white light) and transmit Raman scattered signal light with wavelengths above 785nm. During excitation, the laser beam and white light illumination are reflected by this mirror to the shared microscope objective 4 (i.e., the optical information excitation module), achieving simultaneous focusing of sample illumination and excitation; while the Raman signal light generated by the sample is efficiently transmitted by this mirror and guided into the subsequent signal splitting system.

[0098] The second beam splitter 34 is located in the Raman signal transmission optical path and is used to further separate the Raman scattering signal reflected from the sample: part of the signal light is transmitted and enters the reflection-based Raman spectroscopy detection module 6; the other part of the signal light is reflected and introduced into the transmission-based Raman spectroscopy detection module 7. This lens can be selected with a 50:50 beam splitting ratio or other customized ratios according to the system configuration, taking into account both signal energy distribution and multi-channel synchronous acquisition.

[0099] Furthermore, all the aforementioned optical lenses are mounted in a standard optical support system, featuring angle fine-tuning and spatial positioning capabilities. To achieve high-precision coaxial beam combining and alignment, the position and angle of each lens are meticulously adjusted to ensure that the excitation beam, illumination beam, and Raman signal light form an ideal coaxial or near-coaxial structure in front of the objective lens. The optical axis coincidence error is controlled within ±1μm, ensuring precise correspondence between the image and the spectral acquisition area, thus improving detection consistency and system stability.

[0100] In summary, the optical guidance module, through a reasonable combination of multiple band-selective lenses, achieves spatial integration and path control of white light illumination, 785nm excitation laser, and Raman scattering signal. This provides a structural foundation and path guarantee for the multi-mode microscopic Raman detection function of the system of this invention, and is one of the key core components to ensure the coordinated operation of imaging-excitation-detection.

[0101] Example 10: Optional Variations and Technological Extensions In one embodiment of the present invention, to adapt to different types of samples, application scenarios, and detection requirements, this system possesses good structural compatibility and functional scalability. The following are several optional technical modifications and extended applications of the present invention without changing its basic technical principles and structure: (a) Replaceability of laser excitation wavelength The excitation source described in this system preferably uses a 785nm laser for Raman excitation, which is suitable for most organic samples and materials with weak fluorescence interference. However, in certain specific applications (such as fluorescent labeling, biological tissue analysis, and nanomaterial characterization), the excitation wavelength can be replaced with 532nm or 633nm, depending on the absorption characteristics or Raman scattering efficiency of the sample.

[0102] 532nm lasers are suitable for detecting high Raman efficiency and fluorescence-enhanced components; 633nm lasers are commonly used for biological staining of samples and surface-enhanced Raman (SERS) applications; Lasers of different wavelengths can be integrated into the system through a multi-channel laser switching module to achieve multi-band detection with a single machine.

[0103] (ii) Flexible configuration of Raman spectrometer To meet the requirements for Raman signal detection at different resolutions, speeds, or wavelength ranges, the system of this invention can be equipped with different types of spectrometer components: High-resolution Raman spectrometers (e.g., 0.5–1.0 cm⁻¹) are suitable for applications sensitive to minute displacements, such as crystal structure analysis and stress testing. Rapid scanning spectrometers are suitable for online detection, dynamic process analysis, and high-throughput screening; The spectrometer band range can be customized according to the excitation wavelength and the target Raman shift (e.g., covering 200–2000 cm⁻¹ or extending to 4000 cm⁻¹).

[0104] (III) Optional Configurations of White Light Microscopy System In addition to using a monochrome CCD camera for high-sensitivity imaging, the white light microscopy imaging module can also employ color imaging equipment to enhance tissue identification, pathological diagnosis, or visualization of complex sample structures. Color imaging is suitable for complex tissue samples, living cells, microorganisms, etc. Black and white imaging is suitable for Raman channel-assisted focusing, has high image contrast, and high sensitivity; The image acquisition resolution can be expanded to over 1600×1200 pixels, and it supports functions such as image stitching, zoom imaging, and automatic exposure adjustment.

[0105] (iv) Integration of system expansion function modules To adapt to the diverse needs of different fields (such as biology, materials, environment, and pharmacy) for Raman detection environments, the system of this invention can also be expanded and integrated with the following functional modules: Temperature-controlled sample stage: used to maintain constant temperature detection conditions (such as 37°C), low temperature analysis (such as frozen sections), or monitoring of thermally induced changes; Biological sample culture device: supports long-term cell culture and dynamic monitoring under micro Raman spectroscopy, suitable for cell kinetics and pharmacodynamics studies; Dark box or laser shield: Used to enhance the system's optical stability and laser safety, suitable for detection of highly sensitive or fluorescence-sensitive samples; Automatic sample positioning and scanning platform: Enables two-dimensional or three-dimensional Raman spectroscopy imaging, and supports automatic analysis and data stitching of multiple regions.

[0106] In summary, this invention provides a multi-mode micro-Raman spectroscopy detection system integrating white light microscopy imaging, reflection Raman spectroscopy detection, and transmission Raman spectroscopy detection. By constructing a modular structure with coaxial optical paths, a flexible excitation and detection path control mechanism, and high-precision image-assisted positioning capabilities, it achieves non-destructive acquisition of Raman spectra from different levels and angles of the sample. This system not only improves the spatial consistency and data stability of Raman detection but also enhances its adaptability to complex sample structures. It boasts advantages such as compact structure, high functional integration, and simple operation, making it suitable for multiple technical fields including biomedicine, materials science, and drug analysis, and possessing promising application prospects and widespread application value.

[0107] It should be noted that although the present invention has described the structural configuration and operation in detail with reference to preferred embodiments, those skilled in the art can still make various modifications, substitutions, or equivalent adjustments without departing from the essential content of the present invention. These modifications or improvements should also be considered to fall within the protection scope of the present invention.

[0108] The scope of protection of this invention shall be determined by the appended claims. The embodiments disclosed in the specification and drawings are only used to illustrate the principles of this invention and are not intended to limit the scope of protection of this invention.

Claims

1. A multi-mode micro Raman spectroscopy detection system, characterized in that, include: The white light microscopy module is used to provide a white light illumination source and to acquire white light microscopy images. The reflection Raman spectroscopy excitation module is used to provide a continuous laser source for exciting the reflection Raman spectrum of the sample; The reflection Raman spectroscopy detection module is used to detect the reflection Raman spectral signal of the sample after it is excited. The optical information excitation module is used to focus the excitation light onto the sample and collect the Raman spectrum signal of the sample; The transmission Raman spectroscopy excitation module is used to provide a continuous laser source for exciting the transmission Raman spectrum of the sample; A transmission Raman spectroscopy detection module is used to detect the transmission Raman spectral signal of a sample after it has been excited. The optical guidance module is used to guide and separate the excitation light and signal light from different modules, so as to achieve coaxial convergence or optical path separation of white light illumination light, reflective Raman spectroscopy excitation and detection light, and transmission Raman spectroscopy excitation and detection light between different modules.

2. The multi-mode micro Raman spectroscopy detection system according to claim 1, characterized in that, The white light microscopy imaging module includes: an LED light source, a collimator, a beam expander lens group, a first beam splitter, an imaging lens, and a CCD camera; The illumination light emitted by the LED light source is collimated by the collimator and expanded by the beam expanding lens group in sequence, and then transmitted through the first beam splitter to the optical information excitation module and illuminates the sample. The white light imaging signal reflected from the sample is returned by the optical information excitation module, reflected by the first beam splitter, and then converged by the imaging lens to the CCD camera to complete the acquisition of white light microscopic images.

3. The multi-mode micro Raman spectroscopy detection system according to claim 1, characterized in that, The reflection-type Raman spectroscopy excitation module includes: a first fiber-coupled output continuously adjustable 785nm laser, a first fiber collimator, and a first bandpass filter. The 785nm laser emitted by the first laser is collimated by the first fiber collimator and stray light is filtered out by the first bandpass filter before being guided into the optical guidance module.

4. The multi-mode micro Raman spectroscopy detection system according to claim 1 or 3, characterized in that, The reflection-based Raman spectroscopy detection module includes: a first long-pass filter, a first collecting lens, a pinhole, a second collimating lens, a second imaging lens, a first fiber optic coupler, and a first Raman spectrometer; The reflected Raman signal light excited by the sample passes through the optical information excitation module and the optical guidance module, and then sequentially passes through the first long-pass filter to filter out elastic scattered light, is collected by the first collecting lens and focused onto the pinhole for spatial filtering, is collimated by the second collimating lens, is converged by the second imaging lens, and finally is coupled into the first fiber optic coupler and transmitted to the first Raman spectrometer for signal acquisition.

5. The multi-mode micro Raman spectroscopy detection system according to claim 1, characterized in that, The optical information excitation module is a microscope objective, used to focus the illumination light from the white light microscopic imaging module and / or the excitation light from the reflective Raman spectroscopy excitation module onto the sample, and to collect the white light signal and / or Raman scattering signal returned by the sample.

6. The multi-mode micro Raman spectroscopy detection system according to claim 1, characterized in that, The transmission-type Raman spectroscopy excitation module includes: a second fiber-coupled output continuously adjustable 785nm laser, a second fiber collimator, a second bandpass filter, a converging lens, and a one-dimensional moving platform. The 785nm laser emitted by the second laser is collimated by the second fiber collimator and stray light is filtered out by the second bandpass filter in sequence, and then focused onto the sample by the converging lens; The one-dimensional moving platform is used to support and adjust the position of the converging lens or its components to change the focal point of the excitation light in the sample.

7. The multi-mode micro Raman spectroscopy detection system according to claim 1 or 6, characterized in that, The transmission Raman spectroscopy detection module includes: a second long-pass filter, a third collecting lens, a second fiber optic coupler, and a second Raman spectrometer; The transmitted Raman signal light excited by the sample passes sequentially through the second long-pass filter to filter out elastic scattered light, is collected and focused by the third collecting lens, and finally coupled into the second fiber optic coupler and transmitted to the second Raman spectrometer for signal acquisition.

8. The multi-mode micro Raman spectroscopy detection system according to claim 1, characterized in that, The optical guidance module includes a reflector, a second beam splitter, a dichroic mirror, and a third beam splitter. The reflector is used to reflect the laser from the reflective Raman spectroscopy excitation module to the second beam splitter; The second beam splitter is disposed in the optical path of the white light microscopy module to reflect the laser from the reflector to the dichroic mirror and transmit the white light illumination from the white light microscopy module. The dichroic mirror is disposed on the optical path entrance side of the optical information excitation module, and is used to reflect incident light with a wavelength less than or equal to 785nm to the optical information excitation module, and transmit Raman signal light with a wavelength greater than 785nm. The third beam splitter is disposed in the transmission optical path of the dichroic mirror and is used to transmit the reflected Raman signal light from the sample to the reflection Raman spectroscopy detection module and reflect the transmitted Raman signal light from the sample to the transmission Raman spectroscopy detection module.

9. The multi-mode micro Raman spectroscopy detection system according to claim 4, characterized in that, The pinhole is located at the focal point of the first collecting lens and is used to realize the confocal function of reflective Raman spectroscopy detection to improve spatial resolution and signal-to-noise ratio.

10. The multi-mode micro Raman spectroscopy detection system according to claim 6, characterized in that, The one-dimensional moving platform is an X-axis moving platform, used to precisely adjust the lateral position of the transmission excitation spot on the sample.

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