A confocal imaging system and method based on surface scanning

Abstract

The present invention provides a confocal imaging system and method based on surface scanning, belonging to the technical field of confocal spectral imaging, including: a laser, a first laser beam expander, a second laser beam expander, a cylindrical lens, a dichroic mirror, an array fiber bundle, an imaging lens, a reflector, a microscope objective, a slide of a sample to be measured, a fiber collimator, a diffraction grating, an imaging concave mirror, and a linear array CCD detector; a surface array arrangement end is connected to the left side of the array fiber bundle, and a linear array arrangement end is arranged on the right side of the array fiber bundle; the Raman spectral signals collected by the present invention have high chemical specificity, can distinguish different chemical substances, obtain information such as the content of different molecules, can perform multi-parameter analysis, do not require pretreatment of the sample, do not damage the structure and properties of the sample, can perform in-situ analysis of the sample, and have the characteristics of non-destructiveness, high chemical specificity, high spatial resolution, and multi-parameter analysis, and are suitable for popularization.

Description

Technical Field

[0001] The present invention belongs to the technical field of confocal spectral imaging, and in particular, to a confocal imaging system and method based on area scanning. Background Art

[0002] When a confocal system collects spectral data of a target sample, it can exclude the interference of stray signals at non-focus points, has higher imaging resolution and lower data noise, and is an important means for modern biological research; especially in the analysis and detection of living cells and biological activities, it is of great significance to quickly achieve three-dimensional imaging.

[0003] Specifically, confocal imaging technology is an advanced optical imaging technology based on the principles of laser scanning and conjugate focusing to achieve high-resolution, three-dimensional imaging of samples; its core lies in the precise focusing of the optical path (excitation and emission) at two positions. When the confocal scanner operates, the excitation light is focused on the surface of the sample point through specific optical components, causing the substances in the sample to be excited to generate fluorescence emission or Raman scattering; while the emitted light is focused on the pinhole. The pinhole, as a spatial filter, only allows the spectral signals from the focal plane to pass through, blocking the stray light from non-focal planes, ensuring that the collected optical signals are highly pure, effectively reducing the interference of background noise, and laying a foundation for subsequent high-definition imaging.

[0004] Compared with traditional microscopes, confocal spectral imaging technology has significant advantages, as follows:

[0005] ① Traditional microscope imaging relies on the transmission or reflection of light, and its resolution is restricted by the optical diffraction limit. When observing thick samples or pursuing high-resolution imaging, due to light scattering and absorption, the image is often blurred, and it is difficult to distinguish the signals inside and outside the focal plane, with high background noise; while confocal imaging technology takes advantage of the high coherence, high intensity, and precise focusing characteristics of lasers to break through the traditional diffraction limit. It can not only perform fine optical sectioning on thick fluorescent specimens (up to 50 µm and above), with the section thickness precisely controlled at about 0.5 to 1.5 µm, but also accurately move the specimen along the Z-axis of the microscope to obtain a series of optical section images, and then realize the reconstruction of the three-dimensional morphology of the sample, providing researchers with a precise insight into the microscopic world in the fields of biomedicine, materials science, etc.

[0006] ② From the perspective of resolution, traditional optical microscopes are restricted by the optical diffraction limit, and their lateral resolution is usually in the range of 200-500 nanometers. The axial resolution is even more limited, which makes it difficult to meet the needs of precise observation of microscopic details such as fine structures within cells and fine morphology of nanomaterials. Confocal microscopes rely on the advantages of confocal technology and laser light sources. Some advanced systems can even have a lateral resolution of tens of nanometers, and the axial resolution is also significantly improved. They can clearly distinguish tiny structural differences of samples in three-dimensional space. For example, in cell biology research, they can accurately present the morphology, distribution and interaction relationships of organelles.

[0007] ③ In terms of imaging depth, when traditional microscopes image thick samples, they cannot eliminate the interference of non-focal plane information. As the thickness of the sample increases, the image becomes increasingly blurred and the effective imaging depth is shallow. Confocal microscopes can adjust parameters such as the distance between the objective lens and the sample and the size of the pinhole to scan and image samples within a certain thickness range layer by layer, obtain clear optical sections at different depths, and have an imaging depth of up to hundreds of microns, demonstrating powerful depth detection capabilities in application scenarios such as biological tissue slicing and multi-layer material structure analysis.

[0008] ④ In terms of background noise control, when traditional microscopes are used for imaging, a large amount of background noise such as stray light and scattered light from the non-focal plane of the sample, the surrounding environment, and the optical components themselves is mixed into the imaging light path, seriously reducing the image contrast and clarity; the confocal microscope uses the spatial filtering characteristics of the pinhole to block the non-focal plane noise signal from the source, significantly purifies the imaging background, and greatly improves the image contrast, providing excellent imaging conditions for weak light signal detection and fine structure resolution, which effectively promotes the development of cutting-edge scientific research and high-precision industrial detection.

[0009] However, existing confocal imaging technologies are mainly based on point scanning, which collects characteristic signals of the target area in a point-by-point scanning manner and restores them into an image with intensity as pixel value;

[0010] Traditional point scanning confocal imaging technology has problems such as long time consumption, low efficiency and phototoxicity when detecting optical signals on material surfaces and biological tissue sections, which limits its widespread promotion in practical applications.

[0011] In the prior art, there is also a spinning disk confocal microscope, which innovatively uses a spinning disk structure to replace the traditional single pinhole design. A large number of pinholes are evenly distributed on the spinning disk, and with a high-speed rotation mechanism, high-speed parallel scanning imaging of the sample is achieved. At the moment when the excitation light irradiates the sample, multiple pinholes simultaneously collect signals from different positions, improving the imaging speed. Dozens or even hundreds of frames of images can be obtained per second, effectively capturing the dynamic processes of living cells, such as instantaneous changes in cell migration, mitosis, etc., providing a powerful tool for real-time monitoring research in cell dynamics, developmental biology, etc. At the same time, its imaging resolution and contrast can still maintain a high level under high-speed imaging, showing excellent performance in applications such as observing rapid physiological processes and microbial dynamic behaviors, broadening the boundaries of confocal imaging technology in the field of research on dynamic life phenomena.

[0012] However, the spinning disk confocal system is only suitable for applications in fluorescence intensity and cannot provide more detailed information such as the chemical composition of the sample. Summary of the Invention

[0013] To solve the above technical problems, the present invention provides a confocal imaging system and method based on area scanning. Aiming at the problem of slow scanning speed of traditional single-point confocal spectral imaging technology, a confocal spectral imaging system with area array fast imaging is developed, which improves the three-dimensional confocal spectral imaging efficiency by two orders of magnitude. It can also simultaneously obtain the Raman spectrum and spatial information of the sample, perform multi-parameter analysis, and provide far more sample information than the spinning disk confocal imaging technology in the prior art.

[0014] A confocal imaging system and method based on area scanning, wherein:

[0015] A confocal imaging system based on area scanning includes: a laser, a first laser beam expander, a second laser beam expander, a cylindrical lens, a dichroic mirror, an array fiber bundle, an imaging lens, a reflector, a microscope objective, a slide for the sample to be measured, an optical fiber collimator, a diffraction grating, an imaging concave reflector, and a area array CCD detector; a area array arrangement end is connected to the left side of the array fiber bundle, and a linear array arrangement end is provided on the right side of the array fiber bundle;

[0016] The laser: is used to emit a laser beam;

[0017] The first laser beam expander and the second laser beam expander, as an expansion combination, are jointly used to expand the laser beam;

[0018] The cylindrical lens is used to: focus the expanded laser beam into a linear light spot;

[0019] The dichroic mirror is used for: reflecting the line-shaped light spot, focusing it on the end of the linear array, conducting it through the array optical fiber bundle to the end of the planar array; forming laser emission points arranged in a planar array at the end of the planar array; each of the laser emission points can be regarded as a laser excitation point for laser confocal microscopy;

[0020] The imaging lens is used for: collimating the laser emission points into a series of parallel light beams, then reflecting them through the mirror into the microscopic objective lens for focusing, and then projecting a laser excitation point array pattern with the same arrangement as the laser emission points on the surface of the test sample slide;

[0021] According to the principle of reversibility of light, the Raman scattered light generated by the sample returns, passing through the microscopic objective lens, the mirror, the imaging lens, the end of the planar array, the array optical fiber bundle, and the end of the linear array in sequence. At this time, the emitted scattered signal directly passes through the dichroic mirror and enters the Raman spectrometer, and at this time, the excitation light and Rayleigh scattered light are blocked by the dichroic mirror;

[0022] The Raman scattered light is collimated by an optical fiber collimator and incident on the diffraction grating, where it is dispersed and the diffracted light is conducted to the imaging concave mirror, and then focused on the area array CCD detector through the imaging concave mirror.

[0023] As an example, the cylindrical lens is: a Powell prism.

[0024] As an example, the first laser beam expander and the second laser beam expander are used as an expanding combination to expand the laser beam to between 8 - 10 mm.

[0025] As an example, the first laser beam expander and the second laser beam expander are used as an expanding combination to expand the laser beam to more than 10 mm.

[0026] As an example, the number of the laser emission points is: 2 or more.

[0027] As an example, a test sample is placed on the test sample slide.

[0028] As an example, the imaging concave mirror is: an off-axis aspherical focusing mirror.

[0029] A method for a confocal imaging system based on area scanning includes:

[0030] Step 1: The laser emits a laser beam, which is expanded jointly by the first laser beam expander and the second laser beam expander, and then the expanded laser beam is focused into a line-shaped light spot by the cylindrical lens;

[0031] Step 2: Reflect the linear light spot through a dichroic mirror, focus it on the linear array end, and then conduct it to the area array end through an array fiber bundle to form laser light-emitting points arranged in an area array;

[0032] Step 3: The laser light-emitting points enter an imaging lens, are collimated into a series of parallel lights, and then are reflected by a reflecting mirror and focused in the microscopic objective lens, and projected onto the surface of the sample slide to be measured; at this time, the array pattern formed by the projected laser excitation points is the same as the arrangement of the laser light-emitting points;

[0033] Step 4: When the laser excitation points irradiate the surface of the sample slide to be measured, Raman scattered light is generated at the corresponding positions of the irradiated samples; according to the principle of reversibility of light, the Raman scattered light is collected by the microscopic objective lens, reflected by the reflecting mirror and then reaches the imaging lens, and after being focused by the imaging lens, the Raman scattered light generated by each point on the sample is projected onto the area array end one by one;

[0034] As an example, the Raman signals of the points corresponding to the space on the sample surface are collected by each optical fiber at the area array end; the end face of each optical fiber can be regarded as a confocal pinhole to block the Raman signals of the points around the sample, which greatly improves the signal purity and signal quality of each point.

[0035] Step 5: The Raman scattered light is conducted to the other linear array end through the array fiber bundle, and then after passing through the dichroic mirror, it directly transmits into the fiber collimator, and the excitation light and Rayleigh scattered light are blocked by the dichroic mirror;

[0036] Step 6: The Raman scattered light is collimated by the fiber collimator and incident on a diffraction grating to complete spectral splitting, and the diffracted light is conducted to an imaging concave reflecting mirror and finally focused on a area array CCD detector.

[0037] As an example, the array fiber bundle, the area array end, and the linear array end all include multiple optical fibers, and the number, specifications, and models of the optical fibers of the array fiber bundle, the area array end, and the linear array end are the same as each other.

[0038] As an example, the area array CCD detector includes: an area scanning Raman spectrometer, using a spectrometer with aberration correction as the spectral acquisition device and a large area array CCD as the spectral detector.

[0039] As an example, the Raman scattered light emitted from the linear array end, after the combined action of the fiber collimator, the diffraction grating, and the imaging concave reflecting mirror, is presented on the area array CCD detector. At this time, the Raman scattered light is longitudinally arranged on the CCD target surface in turn according to the arrangement of the optical fibers at the linear array end.

[0040] As an example, the Raman signal of each individual optical fiber, after being split by a diffraction grating, is spread out on the pixel row where the end face of the optical fiber is located. According to the number of pixels occupied by each individual optical fiber, several rows of pixels can be combined to form the Raman spectrum of one optical fiber.

[0041] As an example, the data collected by the entire CCD target surface are the Raman signals of all optical fibers. Through data extraction, the Raman spectrum of each optical fiber can be restored, and from this, the Raman spectrum of the points on the sample corresponding to each optical fiber can be restored, realizing Raman spectrum imaging.

[0042] As an example, the area array CCD detector is electrically connected to the upper computer. After being processed and reorganized by the upper computer, a microscopic image composed of multiple pixel points is reconstructed, and behind each pixel point is a Raman spectrum; through the analysis of the upper computer, a complete Raman spectrum imaging map can be generated according to the types and abundances of chemical substances.

[0043] Advantages of the present invention: The Raman spectrum signal collected by the present invention can not only provide information on the molecular structure and chemical bonds of substances, with high chemical specificity, but also distinguish different chemical substances. By analyzing the intensity of spectral lines, information such as the content of different molecules can also be obtained.

[0044] The Raman spectrum imaging of the present invention can also simultaneously obtain the Raman spectrum and spatial information of the sample, and can perform multi-parameter analysis, such as chemical composition, molecular orientation, crystal structure, etc., and can provide far more sample information than ordinary spinning disk confocal imaging can provide.

[0045] The Raman spectrum imaging of the present invention does not require pre-treatment of the sample, will not damage the structure and properties of the sample, and can perform in-situ analysis of the sample. As a powerful analysis structure and method, it has the characteristics of non-destructiveness, high chemical specificity, high spatial resolution, and multi-parameter analysis, and has broad application prospects in the fields of biomedicine, materials science, environmental science, food safety, etc. Description of the Drawings

[0046] Figure 1 It is the overall structural design drawing of a confocal imaging system based on surface scanning according to the present invention. Detailed Embodiments

[0047] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments; based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0048] A confocal imaging system and method based on area scanning, wherein:

[0049] Reference Figure 1 As shown: A confocal imaging system based on area scanning includes: a laser 1, a first laser beam expander 2, a second laser beam expander 3, a cylindrical lens 4, a dichroic mirror 5, an array fiber optic bundle 6, an imaging lens 7, a mirror 8, a microscope objective 9, a sample slide 10 to be measured, an optical fiber collimator 11, a diffraction grating 12, an imaging concave mirror 13, and a area array CCD detector 14;

[0050] A face array arrangement end 601 is connected to the left side of the array fiber optic bundle 6, and a linear array arrangement end 602 is provided on the right side of the array fiber optic bundle 6;

[0051] The laser 1: is used to emit a laser beam;

[0052] The first laser beam expander 2 and the second laser beam expander 3 are used as an expansion combination to jointly expand the laser beam;

[0053] The cylindrical lens 4 is used to: focus the expanded laser beam into a linear light spot;

[0054] The dichroic mirror 5 is used to: reflect the linear light spot, focus it on the linear array arrangement end 602, and conduct it to the face array arrangement end 601 through the array fiber optic bundle 6; form a face array arrangement of laser emission points at the face array arrangement end 601; each of the laser emission points can be regarded as a laser excitation point for laser confocal;

[0055] The imaging lens 7 is used to: collimate the laser emission points into a series of parallel lights, then reflect them through the mirror 8 into the microscope objective 9 for focusing, and then project an array pattern of laser excitation points with the same arrangement as the laser emission points on the surface of the sample slide 10 to be measured;

[0056] The Raman scattered light generated by the sample returns according to the principle of reversibility of light, and successively passes through the microscope objective 9, the mirror 8, the imaging lens 7, the face array arrangement end 601, the array fiber optic bundle 6, and the linear array arrangement end 602. At this time, the scattered signal emitted passes through the dichroic mirror 5 and directly transmits into the optical fiber collimator. At this time, the excitation light and Rayleigh scattered light are blocked by the dichroic mirror 5;

[0057] As an example, in Raman spectroscopy, the excitation light refers to: the laser used to excite the Raman scattering of the sample. In order to distinguish it from Rayleigh scattered light; in the collected optical signals, there is not only the reflected excitation light, but also Rayleigh scattered light with exactly the same wavelength as the excitation light. These are not the optical signals we want and need to be filtered out using a filter.

[0058] The Raman scattered light is collimated by the fiber collimator 11 and incident on the diffraction grating 12, where it is spectrally dispersed and the diffracted light is conducted to the imaging concave mirror 13, and then focused by the imaging concave mirror 13 onto the area array CCD detector 14.

[0059] As an example, the cylindrical lens 4 is a Powell prism.

[0060] As an example, the first laser beam expander 2 and the second laser beam expander 3 are used as an expander combination to expand the laser beam to a range between 8 - 10 mm.

[0061] As an example, the first laser beam expander 2 and the second laser beam expander 3 are used as an expander combination to expand the laser beam to more than 10 mm.

[0062] As an example, the number of laser emission points is 2 or more.

[0063] As an example, a sample to be measured 15 is placed on the slide 10 to be measured.

[0064] As an example, the imaging concave mirror 13 is an off-axis aspherical focusing mirror.

[0065] A method for a confocal imaging system based on area scanning, comprising:

[0066] Step 1: The laser 1 emits a laser beam, which is expanded by the first laser beam expander 2 and the second laser beam expander 3 together, and then the expanded laser beam is focused into a line-shaped light spot by the cylindrical lens 4;

[0067] Step 2: The line-shaped light spot is reflected by the dichroic mirror 5, focused on the line array end 602, and then conducted to the area array end 601 through the array optical fiber bundle 6 to form laser emission points arranged in an area array;

[0068] Step 3: The laser emission points enter the imaging lens 7, are collimated into a series of parallel light beams, and then reflected by the mirror 8 into the microscopic objective lens 9 for focusing and projected onto the surface of the slide 10 to be measured; at this time, the array pattern formed by the projected laser excitation points is the same as the arrangement of the laser emission points;

[0069] Step 4: When the laser excitation points irradiate the surface of the slide 10 to be measured, Raman scattered light is generated at the corresponding positions of the irradiated sample 15; according to the principle of reversibility of light, the Raman scattered light is collected by the microscopic objective lens 9, reflected by the mirror 8 and then reaches the imaging lens 7, and after being focused by the imaging lens, the Raman scattered light generated at each point on the sample is projected onto the area array end 601 one by one;

[0070] As an example, each optical fiber in the area array arrangement end 601 collects Raman signals of points corresponding to the surface space of the sample; the end face of each optical fiber can be regarded as a confocal pinhole to block the Raman signals of points around the sample, which greatly improves the signal purity and signal quality of each point.

[0071] Step Five: The Raman scattered light is conducted to the other side linear array arrangement end 602 through the array optical fiber bundle 6, and then after passing through the dichroic mirror 5, the Raman scattered light directly transmits into the fiber collimator 11, and the excitation light and Rayleigh scattered light are blocked by the dichroic mirror 5;

[0072] Step Six: The Raman scattered light is collimated by the fiber collimator 11 and incident on the diffraction grating 12 for spectral splitting, and the diffracted light is conducted to the imaging concave mirror 13, and finally focused on the area array CCD detector 14.

[0073] As an example, the array optical fiber bundle 6, the area array arrangement end 601 and the linear array arrangement end 602 all include multiple optical fibers, and the number, specifications and models of the optical fibers in the array optical fiber bundle 6, the area array arrangement end 601 and the linear array arrangement end 602 are the same as each other.

[0074] As an example, the area array CCD detector 14 includes: an area scanning Raman spectrometer, using a spectrometer with aberration correction as the spectral acquisition device and a large area array CCD as the spectral detector.

[0075] As an example, the Raman scattered light emitted from the linear array arrangement end 602, after the combined action of the fiber collimator 11, the diffraction grating 12 and the imaging concave mirror 13, is presented on the area array CCD detector 14. At this time, the Raman scattered light is longitudinally arranged on the CCD target surface in turn according to the fiber arrangement mode of the linear array arrangement end 602.

[0076] As an example, after the Raman signal of each individual optical fiber is split by the diffraction grating, it is expanded on the pixel row where the end face of this optical fiber is located. According to the number of pixels occupied by each individual optical fiber, several rows of pixels can be combined to form the Raman spectrum of one optical fiber.

[0077] As an example, the data collected by the entire CCD target surface are the Raman signals of all optical fibers. Through data extraction, the Raman spectrum of each optical fiber can be restored, and from this, the Raman spectrum of the point on the sample corresponding to each optical fiber can be restored to realize Raman spectrum imaging.

[0078] As an example, the excitation wavelengths of the laser include: 532 nm, 633 nm or 785 nm.

[0079] To better illustrate the design principle of the present invention, a specific example is now given for comparison and detailed elaboration as follows:

[0080] First of all, for a traditional single-point pinhole-coupled confocal system, when performing spectral imaging on a plane, it is necessary to perform point-by-point scanning of the entire plane, resulting in low scanning efficiency;

[0081] To address this problem, the present invention proposes to use a surface and array fiber bundle as the pinhole array for signal collection, and complete the spectral signal acquisition of points on the entire field of view plane at one time.

[0082] Secondly, although the spinning disk confocal can also achieve fast planar signal acquisition, it can only collect the light signal intensity information of the sample plane and cannot distinguish the chemical substances on the sample plane;

[0083] The difference between the present invention and the spinning disk confocal is that the surface and array confocal imaging system collects the spectral signals of the target area. It can not only analyze the abundance of substances on the sample surface through the spectral intensity, but also obtain the information on the chemical composition of the sample surface through the analysis of the spectral lines;

[0084] Then, the line spot fiber coupling scheme adopted in the present invention can make the laser power passing through each fiber tend to be the same, so that the intensity of each pixel point in the imaging field of view of the entire spectral imaging is equal, avoiding the problem of uneven field brightness caused by the illumination intensity uniformity problem in microscopic imaging, and thus correctly reflecting the distribution information of different chemical compositions of the sample in space.

[0085] Again, the Raman lasers adopted in the present invention include but are not limited to 532 nm, 633 nm, and 785 nm. The specific excitation wavelength used depends on the sample. For ordinary materials science samples, a 532 nm excitation line can be used, which can bring higher overall signal intensity and higher acquisition efficiency. For some biological samples and samples with strong fluorescence emission, a 785 nm excitation line can be used, which can effectively avoid the interference of the fluorescence emission of the sample on the Raman spectrum of the sample.

[0086] Finally, the surface array to line array fiber involved in the present invention is arranged in a line at the spectral analysis end. It is both a spatial filter for the excitation light and a spatial modulator for Raman scattering. At the confocal end, it is arranged in a surface array, and each fiber end face is a confocal pinhole, forming a pinhole array with a hexagonal close-packed morphology. At the same time, it is both a confocal excitation pinhole and a confocal collection pinhole, making the entire system exhibit a perfectly matched confocal performance.

[0087] The above are only the preferred embodiments of the present invention. It should be understood that the description of the above embodiments is only used to help understand the method and its core idea of the present invention, and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A confocal imaging system based on surface scanning, characterized in that Including: A laser, a first laser beam expander, a second laser beam expander, a cylindrical lens, a dichroic mirror, an array fiber optic bundle, an imaging lens, a reflector, a microscope objective, a test sample slide, an optical fiber collimator, a diffraction grating, an imaging concave mirror, and a area array CCD detector; A area array arrangement end is connected to the left side of the array fiber optic bundle, and a linear array arrangement end is provided on the right side of the array fiber optic bundle; The laser: is used to emit a laser beam; The first laser beam expander and the second laser beam expander are used as an expander combination to jointly expand the laser beam; The cylindrical lens is used to: focus the expanded laser beam into a linear light spot; The dichroic mirror is used to: reflect the linear light spot, focus it on the linear array arrangement end, conduct it through the array fiber optic bundle to the area array arrangement end; form laser emission points arranged in an area array at the area array arrangement end; each of the laser emission points can be regarded as a laser excitation point for laser confocal microscopy; The imaging lens is used to: collimate the laser emission points into a series of parallel light beams, then reflect them through the reflector into the microscope objective for focusing, and then project a laser excitation point array pattern with the same arrangement as the laser emission points on the surface of the test sample slide; According to the principle of reversibility of light, the Raman scattered light generated by the sample returns, successively passing through the microscope objective, the reflector, the imaging lens, the area array arrangement end, the array fiber optic bundle, and the linear array arrangement end. At this time, the emitted scattered signal directly transmits through the dichroic mirror and enters the optical fiber collimator. At this time, the excitation light and Rayleigh scattered light are blocked by the dichroic mirror; The Raman scattered light is collimated by the optical fiber collimator and incident on the diffraction grating, where it is dispersed and the diffracted light is conducted to the imaging concave mirror, and then focused on the area array CCD detector through the imaging concave mirror.

2. The confocal imaging system based on surface scanning according to claim 1, characterized in that, The cylindrical lens adopts: a Powell prism.

3. A confocal imaging system based on surface scanning according to claim 1, characterized in that, The first laser beam expander and the second laser beam expander, as an expander combination, expand the laser beam to between 8 - 10 mm.

4. A confocal imaging system based on surface scanning according to claim 1, characterized in that, The first laser beam expander and the second laser beam expander, as an expander combination, expand the laser beam to more than 10 mm.

5. The confocal imaging system based on surface scanning according to claim 1, wherein The imaging concave mirror adopts: an off-axis aspherical focusing mirror.

6. A method for a confocal imaging system based on surface scanning, characterized in that, Including: Step 1: The laser emits a laser beam, which is jointly expanded by the first laser beam expander and the second laser beam expander, and then the expanded laser beam is focused into a linear light spot by the cylindrical lens; Step 2: The linear light spot is reflected by the dichroic mirror, focused on the linear array arrangement end, and then conducted through the array fiber optic bundle to the area array arrangement end to form laser emission points arranged in an area array; Step 3: The laser emission points enter the imaging lens, are collimated into a series of parallel light beams, then reflected through the reflector into the microscope objective for focusing, and projected on the surface of the test sample slide; At this time, the array pattern formed by the projected laser excitation points is the same as the arrangement of the laser emission points; Step 4: When the laser excitation point irradiates the surface of the test sample slide, Raman scattered light is generated at the corresponding position of the irradiated sample; according to the principle of reversibility of light, the Raman scattered light is collected by the microscope objective lens, reflected by the mirror and then reaches the imaging lens. After being focused by the imaging lens, the Raman scattered light generated by each point on the sample is projected onto the area array end one by one; Step 5: The Raman scattered light is then conducted to the other side linear array end through the array fiber bundle. Then, after passing through the dichroic mirror, the Raman scattered light directly transmits into the fiber collimator, and the excitation light and Rayleigh scattered light are isolated by the dichroic mirror; Step 6: The Raman scattered light is collimated by the fiber collimator and incident on the diffraction grating to complete spectral splitting, and the diffracted light is conducted to the imaging concave mirror and finally focused on the area array CCD detector.

7. A method for a confocal imaging system based on area scanning according to claim 6, characterized in that Each optical fiber in the area array end collects Raman signals of points corresponding to the spatial position on the sample surface; the end face of each optical fiber can be regarded as a confocal pinhole to block the Raman signals of points around the sample.

8. A method of a confocal imaging system based on surface scanning according to claim 6, characterized in that, The array fiber bundle, the area array end and the linear array end all contain multiple optical fibers, and the number, specifications and models of the optical fibers in the array fiber bundle, the area array end and the linear array end are the same as each other.

9. A method for a confocal imaging system based on surface scanning according to claim 6, characterized in that, The area array CCD detector includes: a surface scanning Raman spectrometer, using a spectrometer with aberration correction as the spectral acquisition device and a large area array CCD as the spectral detector.

10. The method of a confocal imaging system based on surface scanning according to claim 6, characterized in that The Raman scattered light emitted from the linear array end is presented on the area array CCD detector after the combined action of the fiber collimator, the diffraction grating and the imaging concave mirror. At this time, the Raman scattered light is arranged longitudinally in turn on the CCD target surface according to the arrangement of the optical fibers in the linear array end.

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