Combined optical detection system and method based on multispectral microscopic imaging technology and Raman spectrum imaging technology

Abstract

The invention discloses a combined optical detection system and method based on a multispectral microscopic imaging technology and a Raman spectrum imaging technology, and solves the problems that the Raman spectrum imaging technology is extremely weak in signal intensity, easy to be interfered by sample fluorescence and slow in imaging speed, and the multispectral imaging technology is relatively low in spectral resolution. According to the invention, the multispectral microscopic imaging channel and the Raman spectrum imaging channel are ingeniously combined, so that obvious complementary advantages can be formed: global spatial distribution information provided by the multispectral microscopic imaging channel can quickly lock an abnormal point or a region of interest, the Raman spectrum imaging channel is guided to carry out targeted analysis, and invalid scanning time is greatly reduced; and the high chemical specificity of the Raman spectrum imaging channel can be used for performing molecular mechanism interpretation on the substance difference identified by the multispectral microscopic imaging channel, so that a full-chain analysis process of'macroscopic distribution-microscopic verification 'is realized.

Description

Technical Field

[0001] This invention relates to optical detection systems and methods, specifically to a combined optical detection system and method based on multispectral microscopy imaging technology and Raman spectroscopy imaging technology. Background Technology

[0002] In cutting-edge fields such as geological exploration, biological research, and deep space exploration, accurate analysis of material composition and spatial distribution characterization are crucial to the reliability of research conclusions. However, existing single-spectral techniques cannot simultaneously meet the dual requirements of chemical specificity and spatial resolution. Raman spectroscopy, as a "fingerprint recognition" method for molecular structure analysis, can accurately distinguish the chemical composition of substances through characteristic peaks, but it has inherent technical limitations: extremely weak signal intensity, susceptibility to sample fluorescence interference, long single-point acquisition time, and slow imaging speed, making it difficult to achieve rapid screening of large-area samples; at the same time, biological samples are prone to photodamage from prolonged irradiation, limiting its application in live cell research. While multispectral imaging technology can achieve rapid characterization of the spatial distribution of substances through simultaneous acquisition across multiple bands, its spectral resolution is low, making it difficult to distinguish isomers with similar chemical structures, and its sensitivity for detecting trace components is insufficient, failing to provide chemically specific information at the molecular level. Summary of the Invention

[0003] To address the technical challenges of Raman spectroscopy imaging, such as extremely weak signal intensity, susceptibility to sample fluorescence interference, long single-point acquisition time, slow imaging speed, and difficulty in rapid screening of large-area samples, as well as the low spectral resolution of multispectral imaging technology, this invention provides a combined optical detection system and method based on multispectral microscopy imaging technology and Raman spectroscopy imaging technology.

[0004] The inventive concept of this invention: Raman spectroscopy, based on molecular vibrational scattering, is highly sensitive to organic matter, silicate minerals, and other substances with specific chemical bonds, providing precise molecular structure information. Multispectral microscopy, based on the absorption / reflection properties of electronic transitions, is highly sensitive to the macroscopic distribution of components such as iron-containing compounds, chlorophyll, water, and clay minerals. The two technologies complement each other in their detection principles and the types of substances they are sensitive to, making them powerful combined analytical tools. Furthermore, multispectral imaging can achieve large-scale imaging, providing global spatial distribution information, quickly locating regions of interest, and guiding Raman spectroscopy for targeted analysis, thereby significantly reducing the wasted scanning time of Raman spectroscopy. The high chemical specificity of Raman spectroscopy can provide molecular mechanism explanations for differences in substances identified by multispectral imaging, realizing a complete analytical process from "macroscopic distribution to microscopic verification." Therefore, effectively combining the two can overcome the limitations of single-method approaches.

[0005] To achieve the above objectives and complete the above inventive concept, the present invention adopts the following technical solution: A combined optical detection system based on multispectral microscopy and Raman spectroscopy is characterized by the following features: It includes a focusing lens group, a ring lamp group set outside the incident end of the focusing lens group, an imaging spectral dichroic mirror set outside the exit end of the focusing lens group, a multispectral imaging objective lens group and a multispectral imager set outside the transmission end of the imaging spectral dichroic mirror, a scanning galvanometer set outside the reflection end of the imaging spectral dichroic mirror and scanning and reflecting the corresponding light, a laser spectral dichroic mirror set in the optical path of the light reflected by the scanning galvanometer, a laser set outside the transmission end of the laser spectral dichroic mirror, a fiber optic focusing mirror set outside the reflection end of the laser spectral dichroic mirror, and a grating spectrometer connected to the exit end of the fiber optic focusing mirror via an optical fiber. The ring light group, focusing lens group, imaging spectrum dichroic mirror, multispectral imaging objective lens group and multispectral imager constitute a multispectral microscopic imaging channel. The ring lamp group, focusing lens group, imaging spectral dichroic mirror, scanning galvanometer, laser spectral dichroic mirror, fiber focusing lens, optical fiber, and grating spectrometer constitute the spectral acquisition unit of the Raman spectral imaging channel; the ring lamp group, focusing lens group, imaging spectral dichroic mirror, scanning galvanometer, laser spectral dichroic mirror, and laser constitute the laser emission unit of the Raman spectral imaging channel. The ring-shaped light group is used to illuminate the target to be imaged, and includes N monochromatic light sources of different wavelengths; the N monochromatic light sources of different wavelengths are uniformly distributed circumferentially around the central optical axis of the focusing lens group; 4≤N≤10; The scanning galvanometer has an aperture at its working end.

[0006] Furthermore, the focusing lens group includes a fixed lens group arranged sequentially from the incident end to the exit end, a focusing lens group capable of moving along the optical axis, and a driving component for driving the focusing lens group to move.

[0007] Furthermore, the fixed lens assembly includes a first meniscus positive power lens, a second meniscus positive power lens, and a first biconcave negative power lens arranged sequentially from the incident end to the exit end. The focusing lens assembly includes a first biconvex positive power lens and a first meniscus negative power lens arranged sequentially from the incident end to the exit end.

[0008] Furthermore, let the radius of curvature of the front surface of each lens be R1, and the radius of curvature of the rear surface of each lens be R2, then: The first meniscus positive power lens satisfies: |(R1+R2) / (R1-R2)|>15, and both its incident end face and exit end face are curved toward the image side; The second meniscus positive power lens satisfies: |(R1+R2) / (R1-R2)|>15, and both its incident end face and exit end face are curved towards the image side; The first biconcave negative power lens satisfies: -0.9 < (R1 + R2) / (R1 - R2) < -0.3; The first biconvex positive power lens satisfies: -0.3 < (R1 + R2) / (R1 - R2) < 0; The first crescent-shaped negative power lens satisfies: 5<(R1+R2) / (R1-R2)<9, and both its incident end face and exit end face are bent towards the object side.

[0009] Furthermore, the d-line Abbe number of the first meniscus positive power lens is greater than 65; The d-line Abbe number of the second meniscus positive power lens is less than 35; The d-line Abbe number of the first biconcave negative power lens is greater than 65; The d-line Abbe number of the first biconvex positive power lens is greater than 65; The Abbe number of the d-line of the first meniscus negative power lens is less than 35.

[0010] Furthermore, the multispectral imaging objective lens group includes a second biconvex positive power lens, a second biconcave negative power lens, a third biconvex positive power lens, and a second meniscus negative power lens arranged sequentially from the incident end to the exit end.

[0011] Furthermore, the second biconvex positive power lens satisfies: 0.2 < (R1 + R2) / (R1 - R2) < 0.6; The second biconcave negative power lens satisfies: -1 < (R1 + R2) / (R1 - R2) < -0.6; The third biconvex positive power lens satisfies: 0.4 < (R1 + R2) / (R1 - R2) < 0.8; The second meniscus negative power lens satisfies: |(R1+R2) / (R1-R2)|>15.

[0012] Furthermore, the d-line Abbe number of the second biconvex positive power lens is greater than 65; The Abbe number of the d-line of the second biconcave negative power lens is between 40 and 60; The Abbe number of the third biconvex positive power lens is greater than 65; The Abbe number of the d-line of the second meniscus negative power lens is between 40 and 60.

[0013] Furthermore, the ring light assembly includes 16 monochromatic light sources, wherein each wavelength corresponds to two symmetrically distributed monochromatic light sources.

[0014] Furthermore, the moving range of the focusing lens group is L, and 8mm≤L≤16mm.

[0015] A combined optical detection method based on multispectral microscopy and Raman spectroscopy, employing the aforementioned combined optical detection system, acquires Raman spectral data of target anomalies or regions of interest; its key feature is that it includes the following steps: Step 1: Turn on all the monochromatic light sources in the ring light group; Step 2: Adjust the focusing lens group to traverse all its focusing positions, and image the target at each focusing position using a multispectral imager. Calculate the sharpness of each image, and record the position corresponding to the image with the highest sharpness as the optimal focusing position. Step 3: Adjust the focusing lens group to the optimal focusing position, turn off the ring light group, and then turn on each monochromatic light source in the ring light group one by one. When each monochromatic light source is turned on, image the target through the multispectral imager to obtain a multispectral image of the corresponding spectral band. Step 4: Identify anomalies or regions of interest in the target using multispectral images; Step 5: Adjust the scanning mirror to align with the abnormal point or region of interest, turn on the laser to scan the target, and collect the corresponding Raman spectral data through the grating spectrometer to complete the joint optical detection.

[0016] A combined optical detection method based on multispectral microscopy and Raman spectroscopy, employing the aforementioned combined optical detection system based on multispectral microscopy and Raman spectroscopy, acquires a fused image of the target material's composition and morphology information; its unique feature lies in including the following steps: Step 1: Turn on all the monochromatic light sources in the ring light group; Step 2: Adjust the focusing lens group to traverse all its focusing positions, and image the target at each focusing position using a multispectral imager. Calculate the sharpness of each image, and record the position corresponding to the image with the highest sharpness as the optimal focusing position. Step 3: Adjust the focusing lens group to the optimal focusing position, turn off the ring light group, and then turn on each monochromatic light source one by one. When each monochromatic light source is turned on, use a multispectral imager to obtain a multispectral image of the corresponding spectral band. Step 4: Start the laser, adjust the scanning mirror to scan the target point by point, and collect the Raman spectrum data of each scanning point using a grating spectrometer; Step 5: Obtain the material composition map of the target based on the Raman spectral data obtained in Step 4, and fuse it with the multispectral image obtained in Step 3 to obtain a fused image that can present the material composition and morphology information of the target, thus completing the joint optical detection.

[0017] The beneficial effects of this invention are: 1. The combined optical detection system and method based on multispectral microscopy and Raman spectroscopy provided by this invention cleverly combines the multispectral microscopy and Raman spectroscopy channels, resulting in significant complementary advantages: the global spatial distribution information provided by the multispectral microscopy channel can quickly locate anomalies or regions of interest, guiding the Raman spectroscopy channel to perform targeted analysis and significantly reducing invalid scanning time; while the high chemical specificity of the Raman spectroscopy channel can explain the molecular mechanisms of the differences in substances identified by the multispectral microscopy channel, realizing a full-chain analysis process of "macroscopic distribution - microscopic verification"; this combined detection mode can quickly locate the micro-regional component distribution of ores in geological exploration, achieve simultaneous observation of cell morphology and molecular metabolism in biological research, and complete the comprehensive analysis of astronomical samples through a miniaturized integrated system in deep space exploration, significantly improving detection efficiency and result reliability.

[0018] 2. This invention features N monochromatic light sources of different wavelengths; these N monochromatic light sources are evenly distributed circumferentially around the central optical axis of the focusing lens group; compared to the traditional filter wheel scheme, the structure is simpler, and it also solves the lighting problem in dark environments.

[0019] 3. The focusing lens group and multispectral imaging objective lens group provided by the present invention can achieve apochromatic aberration covering a wide spectral range of 400-1700nm by combining their various parameters. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an embodiment of the combined optical detection system based on multispectral microscopy and Raman spectroscopy imaging technology of the present invention; Figure 2 This is a schematic diagram of the ring-shaped lamp assembly in an embodiment of the present invention; Figure 3 This is a schematic diagram of the focusing lens assembly in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the multispectral imaging objective lens assembly in an embodiment of the present invention; Figure 5 This is the fused image formed in the embodiments of the present invention.

[0021] The attached figures are labeled as follows: 1-Ring lamp assembly, 2-Focusing lens assembly, 3-Imaging spectral dichroic mirror, 4-Multispectral imaging objective lens assembly, 5-Multispectral imager, 6-Scanning galvanometer, 7-Laser spectral dichroic mirror, 8-Laser, 9-Fiber optic focusing lens, 10-Fiber optic cable, 11-Grating spectrometer, 2-1-Fixed lens assembly, 2-2-Focusing lens assembly, 2-1-1-First meniscus positive power lens, 2-1-2-Second meniscus positive power lens, 2-1-3-First biconcave negative power lens, 2-2-1-First biconvex positive power lens, 2-2-2-First meniscus negative power lens, 4-1-Second biconvex positive power lens, 4-2-Second biconcave negative power lens, 4-3-Third biconvex positive power lens, 4-4-Second meniscus negative power lens. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention provides a combined optical detection system based on multispectral microscopy and Raman spectroscopy imaging techniques, such as... Figure 1 As shown, the combined optical detection system includes a focusing lens group 2, a ring lamp group 1 located outside the incident end of the focusing lens group 2, an imaging spectral dichroic mirror 3 located outside the exit end of the focusing lens group 2, a multispectral imaging objective lens group 4 and a multispectral imager 5 located outside the transmission end of the imaging spectral dichroic mirror 3, a scanning galvanometer 6 located outside the reflection end of the imaging spectral dichroic mirror 3 and scanning and reflecting the corresponding light, a laser spectral dichroic mirror 7 located on the optical path of the light reflected by the scanning galvanometer 6, a laser 8 located outside the transmission end of the laser spectral dichroic mirror 7, a fiber optic focusing mirror 9 located outside the reflection end of the laser spectral dichroic mirror 7, and a grating spectrometer 11 connected to the exit end of the fiber optic focusing mirror 9 via an optical fiber 10.

[0024] like Figure 2 As shown, the ring light group 1 is used to illuminate the target to be imaged, including N monochromatic light sources of different wavelengths; the N monochromatic light sources of different wavelengths are evenly distributed around the central optical axis of the focusing lens group 2; 4≤N≤10; in this embodiment, N=16, and the monochromatic light source is specifically a monochromatic LED light, wherein each wavelength corresponds to two symmetrically distributed monochromatic LED lights; the installation angle of the monochromatic LED lights can be appropriately tilted inward to ensure that the LED illumination field of view covers the imaging field of view.

[0025] like Figure 3As shown, the focusing lens group 2 includes a fixed lens group 2-1 arranged sequentially from the incident end to the exit end, a focusing lens group 2-2 movable along the optical axis, and a driving component for moving the focusing lens group 2-2. The fixed lens group 2-1 includes a first meniscus positive power lens 2-1-1, a second meniscus positive power lens 2-1-2, and a first biconcave negative power lens 2-1-3 arranged sequentially from the incident end to the exit end. The focusing lens group 2-2 includes a first biconvex positive power lens 2-2-1 and a first meniscus negative power lens 2-2-2 arranged sequentially from the incident end to the exit end. The moving range of the focusing lens group 2-2 is L, and 8mm ≤ L ≤ 16mm. Focusing at an object distance of 100mm-300mm is achieved through the axial movement of the focusing lens group 2-2.

[0026] Let the radius of curvature of the front surface of each lens be R1, and the radius of curvature of the rear surface of each lens be R2, then: The first crescent-shaped positive power lens 2-1-1 satisfies: |(R1+R2) / (R1-R2)|>15, its incident end face and exit end face are both curved towards the image side, and its d-line Abbe number is greater than 65; The second crescent-shaped positive power lens 2-1-2 satisfies: |(R1+R2) / (R1-R2)|>15, its incident end face and exit end face are both curved towards the image side, and its d-line Abbe number is less than 35; The first biconcave negative power lens 2-1-3 satisfies: -0.9 < (R1+R2) / (R1-R2) < -0.3, and its d-line Abbe number is greater than 65; The first biconvex positive power lens 2-2-1 satisfies: -0.3<(R1+R2) / (R1-R2)<0, and its d-line Abbe number is greater than 65; The first crescent-shaped negative power lens 2-2-2 satisfies: 5<(R1+R2) / (R1-R2)<9, its incident end face and exit end face are both bent towards the object side, that is, both are bent towards the exit pupil direction, and its d-line Abbe number is less than 35.

[0027] like Figure 4 As shown, the multispectral imaging objective lens group 4 includes a second biconvex positive power lens 4-1, a second biconcave negative power lens 4-2, a third biconvex positive power lens 4-3, and a second meniscus negative power lens 4-4, arranged sequentially from the incident end to the exit end. The multispectral imaging objective lens group 4 is used to collect light in different wavelength bands, enabling precise imaging and providing a high-quality, multi-band imaging foundation for subsequent spectral analysis and target identification.

[0028] The second biconvex positive power lens 4-1 satisfies: 0.2 < (R1 + R2) / (R1 - R2) < 0.6, and its d-line Abbe number is greater than 65; The second biconcave negative power lens 4-2 satisfies: -1 < (R1 + R2) / (R1 - R2) < -0.6, and its d-line Abbe number is between 40 and 60; The third biconvex positive power lens 4-3 satisfies: 0.4 < (R1 + R2) / (R1 - R2) < 0.8, and its d-line Abbe number is greater than 65; The second crescent-shaped negative power lens 4-4 satisfies: |(R1+R2) / (R1-R2)|>15, and its d-line Abbe number is between 40 and 60.

[0029] The imaging spectral dichroic mirror 3 is used to divide the joint optical detection system into a multispectral microscopic imaging channel and a Raman spectral imaging channel. The two channels share the ring lamp group 1, the focusing mirror group 2, and the imaging spectral dichroic mirror 3. Specifically, the multispectral microscopic imaging channel includes the ring lamp group 1, the focusing mirror group 2, the imaging spectral dichroic mirror 3, the multispectral imaging objective lens group 4, and the multispectral imager 5. The multispectral microscopic imaging channel acquires single-wavelength microscopic images by successively lighting up monochromatic LEDs. The Raman spectroscopy imaging channel includes a ring lamp group 1, a focusing lens group 2, an imaging spectral dichroic mirror 3, a scanning galvanometer 6, a laser spectral dichroic mirror 7, a laser 8, a fiber optic focusing lens 9, an optical fiber 10, and a grating spectrometer 11. The laser spectral dichroic mirror 7 divides the optical path into a laser emission path (corresponding to the laser emission unit) and a spectral acquisition path (corresponding to the spectral acquisition unit). The laser emission unit includes the ring lamp group 1, the focusing lens group 2, the imaging spectral dichroic mirror 3, the scanning galvanometer 6, the laser spectral dichroic mirror 7, and the laser 8. The spectral acquisition unit includes the ring lamp group 1, the focusing lens group 2, the imaging spectral dichroic mirror 3, the scanning galvanometer 6, the laser spectral dichroic mirror 7, the fiber optic focusing lens 9, the optical fiber 10, and the grating spectrometer 11.

[0030] The scanning galvanometer 6 has an aperture at its working end, and the area array is scanned point by point by rotating the scanning galvanometer 6 in two dimensions.

[0031] The wavelength of laser 8 is 532nm or 785nm. If the wavelength of laser 8 is 532nm, the detection range of the Raman spectroscopy imaging channel is 540nm-670nm, and the spectral range of the multispectral microscopy imaging channel is: 3-9 wavelength points selected within the range of 400nm and 750nm-1500nm. If the wavelength of laser 8 is 785nm, the detection range of the Raman spectroscopy imaging channel is 750nm-1120nm, and the spectral range of the multispectral microscopy imaging channel is: 4-10 wavelength points selected within the range of 400nm-750nm and 1200nm-1500nm. The imaging spectral dichroic mirror 3 and the laser spectral dichroic mirror 7 are responsible for the dispersion of these spectra.

[0032] The laser emitted from laser 8 is transmitted through laser spectral dichroism 7 to scanning galvanometer 6, then reflected by scanning galvanometer 6 to imaging spectral dichroism 3, and then reflected by imaging spectral dichroism 3 to focusing lens group 2. The focusing lens group 2 focuses the laser onto the target surface, and the target surface generates a Raman spectrum. The laser then passes through focusing lens group 2, imaging spectral dichroism 3, scanning galvanometer 6, laser spectral dichroism 7, and fiber optic focusing lens 9 in sequence for focusing.

[0033] The fiber optic focusing lens 9 is used to converge the diverging beam into a small focal point or parallel light, so as to realize the concentrated transmission or precise coupling of light energy to the fiber optic 10, and then transmit it to the grating spectrometer 11 through the fiber optic 10.

[0034] The grating spectrometer 11 is used to form a spectrum by decomposing polychromatic light through grating diffraction, so as to analyze and measure the wavelength, intensity, light source composition, and material properties of light.

[0035] The first combined optical detection method provided in this embodiment employs the aforementioned combined optical detection system based on multispectral microscopic imaging and Raman spectral imaging to acquire Raman spectral data of the target key region (i.e., anomaly point or region of interest); specifically, it includes the following steps: Step 1: Turn on all the monochromatic light sources in ring light group 1; Step 2: Adjust the focusing lens group 2 to traverse all its focusing positions. In this embodiment, the movement range of the focusing lens group 2-2 is subdivided into 100 steps. Each time the focusing lens group 2-2 moves one step, the target is imaged once by the multispectral imager 5. The sharpness of each image is calculated, and the position corresponding to the image with the highest sharpness is recorded as the optimal focusing position. Step 3: Adjust the focusing lens group 2 to the optimal focusing position, turn off the ring light group 1, and then turn on each monochromatic light source in the ring light group 1 one by one. When each monochromatic light source is turned on, image the target through the multispectral imager 5 to obtain a multispectral image of the corresponding spectral band. Step 4: Identify anomalies or regions of interest in the target using multispectral images; Step 5: Adjust the scanning galvanometer 6 to align with the anomaly point or region of interest, turn on the laser 8, and collect the corresponding Raman spectral data through the grating spectrometer 11 to complete the joint optical detection.

[0036] The second combined optical detection method provided in this embodiment employs the aforementioned combined optical detection system based on multispectral microscopic imaging technology and Raman spectroscopy imaging technology to obtain a fused image of the target material's composition and morphology information; it includes the following steps: Step 1: Turn on all the monochromatic light sources in ring light group 1; Step 2: Adjust the focusing lens group 2 to traverse all its focusing positions. In this embodiment, the movement range of the focusing lens group 2-2 is subdivided into 100 steps. Each time the focusing lens group 2-2 moves one step, the target is imaged once by the multispectral imager 5. The sharpness of each image is calculated, and the position corresponding to the image with the highest sharpness is recorded as the optimal focusing position. Step 3: Adjust the focusing lens group 2 to the optimal focusing position, turn off the ring light group 1, and then light up each monochromatic light source one by one. When each monochromatic light source is lit, image it through the multispectral imager 5 to obtain a multispectral image of the corresponding spectral band. Step 4: Start the laser 8, adjust the scanning galvanometer 6 so that the scanning galvanometer 6 scans the target point by point within its field of view (the spacing between scanning points and the scanning range can be preset), and collect the Raman spectrum data of each scanning point through the grating spectrometer 11. Step 5: Obtain the material composition map of the target based on the Raman spectral data obtained in Step 4, and fuse it with the multispectral image obtained in Step 3 to obtain the following result: Figure 5 The image shown is a fused image that presents the composition and morphology information of the target material. The base image is a microscopic multispectral image, and the colored dots are Raman acquisition points. Different colors represent different components, thus completing the joint optical detection.

[0037] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A combined optical detection system based on multi-spectral microscopic imaging technology and Raman spectral imaging technology, characterized in that: it comprises a focusing lens group (2), a ring-shaped lamp group (1) arranged outside the incident end of the focusing lens group (2), an imaging spectral dichroic mirror (3) arranged outside the outgoing end of the focusing lens group (2), a multi-spectral imaging objective lens group (4) and a multi-spectral imaging instrument (5) arranged in turn outside the transmission end of the imaging spectral dichroic mirror (3), a scanning galvanometer (6) arranged outside the reflection end of the imaging spectral dichroic mirror (3) and capable of scanning and reflecting corresponding light, a laser spectral dichroic mirror (7) arranged on the light path of the light reflected by the scanning galvanometer (6), a laser (8) arranged outside the transmission end of the laser spectral dichroic mirror (7), a fiber focusing mirror (9) arranged outside the reflection end of the laser spectral dichroic mirror (7), and a grating spectrometer (11) connected to the outgoing end of the fiber focusing mirror (9) through a fiber (10); the ring-shaped lamp group (1), the focusing lens group (2), the imaging spectral dichroic mirror (3), the multi-spectral imaging objective lens group (4) and the multi-spectral imaging instrument (5) constitute a multi-spectral microscopic imaging channel; the ring-shaped lamp group (1), the focusing lens group (2), the imaging spectral dichroic mirror (3), the scanning galvanometer (6), the laser spectral dichroic mirror (7), the fiber focusing mirror (9), the fiber (10) and the grating spectrometer (11) constitute a spectral collection unit of a Raman spectral imaging channel; and the ring-shaped lamp group (1), the focusing lens group (2), the imaging spectral dichroic mirror (3), the scanning galvanometer (6), the laser spectral dichroic mirror (7) and the laser (8) constitute a laser emission unit of the Raman spectral imaging channel. The ring-shaped lamp group (1) is used for illuminating a target to be imaged and comprises N monochromatic light sources with different wavelengths; the N monochromatic light sources with different wavelengths are uniformly distributed around the central optical axis of the focusing lens group (2); 4≤N≤10. An aperture is arranged on the acting end of the scanning galvanometer (6). 2.The combined optical detection system based on multi-spectral microscopic imaging technology and Raman spectral imaging technology according to claim 1, characterized in that: the focusing lens group (2) comprises a fixed lens group (2-1), a focusing lens group (2-2) capable of moving along the optical axis and arranged in turn from the incident end to the outgoing end, and a driving member for driving the focusing lens group (2-2) to move. 3.The combined optical detection system based on multi-spectral microscopic imaging technology and Raman spectral imaging technology according to claim 2, characterized in that: the fixed lens group (2-1) comprises a first meniscus positive focal length lens (2-1-1), a second meniscus positive focal length lens (2-1-2) and a first double-concave negative focal length lens (2-1-3) arranged in turn from the incident end to the outgoing end; and the focusing lens group (2-2) comprises a first double-convex positive focal length lens (2-2-1) and a first meniscus negative focal length lens (2-2-2) arranged in turn from the incident end to the outgoing end. 4.The combined optical detection system based on multi-spectral microscopic imaging technology and Raman spectral imaging technology according to claim 3, characterized in that: ​ ​ ​ ​ ​ ​ Definition, the front surface curvature radius of each lens is R1, the back surface curvature radius of each lens is R2, then: The first meniscus positive power lens (2-1-1) satisfies: |(R1+R2) / (R1-R2)|>15, and both the entrance end face and the exit end face are curved towards the image side; The second meniscus positive power lens (2-1-2) satisfies: |(R1+R2) / (R1-R2)|>15, and both the entrance end face and the exit end face are curved towards the image side; The first double-concave negative power lens (2-1-3) satisfies: -0.9<(R1+R2) / (R1-R2)<-0.3; The first double-convex positive power lens (2-2-1) satisfies: -0.3<(R1+R2) / (R1-R2)<0; The first meniscus negative power lens (2-2-2) satisfies: 5<(R1+R2) / (R1-R2)<9, and both the entrance end face and the exit end face are curved towards the object side.

5. The combined optical detection system based on multispectral microscopic imaging technology and Raman spectral imaging technology according to claim 4, characterized in that: The d-line Abbe number of the first meniscus positive power lens (2-1-1) is greater than 65; The d-line Abbe number of the second meniscus positive power lens (2-1-2) is less than 35; The d-line Abbe number of the first double-concave negative power lens (2-1-3) is greater than 65; The d-line Abbe number of the first double-convex positive power lens (2-2-1) is greater than 65; The d-line Abbe number of the first meniscus negative power lens (2-2-2) is less than 35.

6. The combined optical detection system based on multispectral microscopic imaging technology and Raman spectral imaging technology according to any one of claims 2-5, characterized in that: The multispectral imaging objective lens group (4) comprises, in order from the entrance end to the exit end, a second double-convex positive power lens (4-1), a second double-concave negative power lens (4-2), a third double-convex positive power lens (4-3), and a second meniscus negative power lens (4-4).

7. The combined optical detection system based on multispectral microscopic imaging technology and Raman spectral imaging technology according to claim 6, characterized in that: The second double-convex positive power lens (4-1) satisfies: 0.2<(R1+R2) / (R1-R2)<0.6; The second double-concave negative power lens (4-2) satisfies: -1<(R1+R2) / (R1-R2)<-0.6; The third double-convex positive power lens (4-3) satisfies: 0.4<(R1+R2) / (R1-R2)<0.8; The second meniscus negative power lens (4-4) satisfies: |(R1+R2) / (R1-R2)|>15.

8. The combined optical detection system based on multispectral microscopic imaging technology and Raman spectral imaging technology according to claim 7, characterized in that: The d-line Abbe number of the second double-convex positive power lens (4-1) is greater than 65; The d-line Abbe number of the second double-concave negative power lens (4-2) is between 40-60; The d-line Abbe number of the third double-convex positive power lens (4-3) is greater than 65; The d-line Abbe number of the second meniscus negative power lens (4-4) is between 40-60.

9. The combined optical detection system based on multispectral microscopic imaging technology and Raman spectral imaging technology according to claim 8, characterized in that: The annular lamp group (1) comprises 16 monochromatic light sources, wherein two monochromatic light sources of each wavelength are symmetrically distributed.

10. The combined optical detection system based on multispectral microscopic imaging technology and Raman spectral imaging technology according to claim 2, characterized in that: The moving range of the focusing lens group (2-2) is L, and 8mm≤L≤16mm.

11. A combined optical detection method based on multispectral microscopic imaging technology and Raman spectral imaging technology, using the combined optical detection system based on multispectral microscopic imaging technology and Raman spectral imaging technology according to any one of claims 1-10 to obtain Raman spectral data of target abnormal points or regions of interest; characterized in that, The method comprises the following steps: Step 1, turn on all monochromatic light sources in the annular lamp group (1); Step 2, adjust the focusing lens group (2) to traverse all focusing positions thereof, and image the target at each focusing position by the multispectral imager (5), calculate the sharpness of each image, and record the position corresponding to the image with the highest sharpness as the best focusing position; Step 3, adjust the focusing lens group (2) to the best focusing position, turn off the annular lamp group (1), then turn on each monochromatic light source in the annular lamp group (1) one by one, and image the target by the multispectral imager (5) when each monochromatic light source is turned on, to obtain a multispectral image of the corresponding spectral band; Step 4, identify the abnormal points or regions of interest of the target from the multispectral images; Step 5, adjust the scanning galvanometer (6) to align with the abnormal points or regions of interest, turn on the laser (8) to scan the target, and collect the corresponding Raman spectral data by the grating spectrometer (11), to complete the combined optical detection.

12. A combined optical detection method based on multispectral microscopic imaging technology and Raman spectral imaging technology, using the combined optical detection system based on multispectral microscopic imaging technology and Raman spectral imaging technology according to any one of claims 1-10 to obtain a fusion image of the composition information and the topography information of the target substance; characterized in that, The method comprises the following steps: Step 1, turn on all monochromatic light sources in the annular lamp group (1); Step 2, adjust the focusing lens group (2) to traverse all focusing positions thereof, and image the target at each focusing position by the multispectral imager (5), calculate the sharpness of each image, and record the position corresponding to the image with the highest sharpness as the best focusing position; Step 3, adjust the focusing lens group (2) to the best focusing position, turn off the annular lamp group (1), then turn on each monochromatic light source one by one, and image by the multispectral imager (5) when each monochromatic light source is turned on, to obtain a multispectral image of the corresponding spectral band; Step 4, start the laser (8), and adjust the scanning galvanometer (6) to scan the target point by point, and collect the Raman spectral data of each scanning point by the grating spectrometer (11); Step 5, obtain the material composition map of the target according to the Raman spectral data obtained in step 4, and fuse the multispectral image obtained in step 3, to obtain a fused image capable of presenting the material composition information and topographic information of the target, to complete the combined optical detection.

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