High-speed Raman spectrum imaging device

Abstract

The utility model provides a high-speed Raman spectrum imaging device. The high-speed Raman spectrum imaging device at least comprises a laser module, a beam splitter, an objective lens, a translation module, a focusing element and a spectrograph, the translation module, the objective lens, the beam splitter, the focusing element and the spectrograph are sequentially arranged, and a sample is arranged on the translation module; the laser module is arranged at a certain included angle relative to the beam splitter; the laser module is used for generating multiple beams of non-parallel laser; the beam splitter reflects the laser emitted by the laser module to the objective lens and allows the Raman signal light to penetrate, so that the Raman signal light is collected by the focusing element; the objective lens focuses the multiple beams of non-parallel laser reflected by the beam splitter to different positions of the sample, and collimates the Raman signal light returned after the laser irradiates the sample into multiple beams of non-parallel Raman signal light; the focusing element collects the Raman signal light penetrating through the beam splitter into the spectrograph; the spectrograph is used for simultaneously collecting Raman spectrums at different positions of the sample; the translation module is used for moving the sample. Therefore, rapid and comprehensive collection of the Raman spectrum is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of spectral detection and analysis, and particularly relates to a high-speed Raman spectroscopic imaging device. Background Art

[0002] Raman spectroscopic imaging technology combines the advantages of Raman spectroscopy and imaging, and can provide chemical composition and spatial distribution information of samples, and has been widely used in the fields of materials science, life science, medicine, environmental science, etc.: Using Raman spectroscopic imaging technology, the chemical composition information on the surface and inside of materials can be obtained non-destructively, which is used to study the structure, defects, phase transitions, etc. of materials, so as to guide the design and preparation of materials; Using Raman spectroscopic imaging technology, the chemical composition analysis of cells and tissues can be carried out, and the distribution of different molecules in biological samples can be observed, which is used for cancer diagnosis and drug efficacy evaluation; Using Raman spectroscopic imaging technology, Raman spectroscopic imaging of samples such as the atmosphere, water body, and soil can be carried out, so as to quickly and accurately determine the components such as organic matter, inorganic matter, and microorganisms in the samples, which is used to monitor the degree of environmental pollution and evaluate the environmental quality.

[0003] The existing Raman spectroscopic imaging systems often use the combination of a filter and a CCD camera to collect Raman images. To collect Raman images of different Raman peaks, it is necessary to replace the filter or change the laser wavelength, and it is difficult to achieve high spectral resolution; The method of using a spectrometer and a displacement stage to perform single-point Raman spectroscopy scanning of the sample can achieve high spectral resolution and obtain more comprehensive Raman information, but there are problems of low collection rate and slow imaging speed; Using a microlens array can improve the imaging speed, but there are problems such as low Raman spectrum collection efficiency.

[0004] Therefore, a high-speed Raman spectroscopic imaging device is needed to solve or at least partially solve the above problems. Summary of the Utility Model

[0005] The utility model provides a high-speed Raman spectroscopic imaging device to achieve rapid and comprehensive collection of Raman spectra.

[0006] To achieve the above object, the utility model provides the following technical solutions.

[0007] The utility model provides a high-speed Raman spectroscopic imaging device, which at least includes a laser module, a beam splitter, an objective lens, a translation module, a focusing element and a spectrometer; The translation module, the objective lens, the beam splitter, the focusing element and the spectrometer are arranged in sequence, a sample is arranged on the translation module, and the objective lens, the beam splitter, the focusing element and the spectrometer form a confocal optical path; The laser module is arranged at a certain angle relative to the beam splitter;

[0008] The laser module is used to generate multiple non-parallel laser beams;

[0009] The beam splitter reflects the laser emitted by the laser module to the entrance pupil of the objective lens and allows the Raman signal light to penetrate, so as to be collected by the focusing element;

[0010] The objective lens focuses multiple non-parallel laser beams reflected by the beam splitter to different positions of the sample, and collimates the Raman signal light returned from the laser irradiated on the sample into multiple non-parallel Raman signal beams;

[0011] The focusing element collects the Raman signal light penetrating the beam splitter into the spectrometer and projects it onto different row pixels of the area array CCD camera of the spectrometer respectively;

[0012] The spectrometer is used to simultaneously collect Raman spectra at different positions of the sample;

[0013] The translation module is used to move the sample.

[0014] Preferably, the angle of the laser emitted by the laser module is adjustable. By adjusting the incident angle of the laser emitted by the laser module to the beam splitter, the collection position of the sample for single Raman spectrum collection is adjusted.

[0015] Preferably, the beam splitter is a spectroscopic prism, a planar beam splitter or a dichroic mirror. The beam splitter divides the incident light beam into two parts, one part is transmitted through and the other part is reflected.

[0016] Preferably, the sample is arranged on the focal plane of the objective lens, and the objective lens includes at least one lens.

[0017] Preferably, the translation module includes at least one displacement stage, and the translation module drives the sample to move on the focal plane of the objective lens.

[0018] Preferably, the focusing element is at least composed of one or more combinations of a convex lens and a concave mirror.

[0019] Preferably, the slit of the spectrometer coincides with the rear focal plane of the focusing element.

[0020] Compared with the prior art, the technical solution of the embodiment of the present utility model has beneficial effects.

[0021] For example, the present utility model scans the Raman spectrum of a wide area of the sample through the translation module, can simultaneously collect Raman spectrum data at different positions of the same sample, improves the collection throughput, and thus greatly improves the Raman spectrum imaging speed; adopting a backscattering geometry configuration, the excitation light and the Raman signal light are focused and collimated through the same objective lens, ensuring the power density of the excitation light and the collection efficiency of the Raman signal, and can be used for the detection of weak signals;

[0022] For another example, by adjusting the incident angle of the laser emitted by the laser module onto the beam splitter, precise control of the sample measurement position in single-shot Raman spectroscopy acquisition is achieved, which is more flexible and has strong applicability. Description of the Drawings

[0023] Figure 1 is the optical path diagram of the high-speed Raman spectroscopy imaging device in an embodiment of the present invention;

[0024] Figure 2 is the Raman spectroscopy imaging diagram of the high-speed Raman spectroscopy imaging device in an embodiment of the present invention for measuring a silicon wafer with a mark, where Figure 2 (a) is the Raman spectroscopy imaging of selecting the 520 cm -1 Raman characteristic peak of silicon;

[0025] Figure 2 (b) is the bright-field imaging of the sample;

[0026] Figure 3 is the Raman spectroscopy imaging diagram of the high-speed Raman spectroscopy imaging device in an embodiment of the present invention for measuring a quartz glass tube filled with anhydrous ethanol, where Figure 3 (a) is the Raman spectroscopy imaging of selecting the 884 cm -1 Raman characteristic peak of anhydrous ethanol;

[0027] Figure 3 (b) is the Raman spectroscopy imaging of selecting the 608 cm -1 Raman characteristic peak of the quartz glass tube.

[0028] Description of the Reference Numerals:

[0029] 1 - Laser module; 2 - Beam splitter; 3 - Objective lens; 4 - Sample; 5 - Translation module; 6 - Focusing element; 7 - Spectrometer. Detailed Embodiments

[0030] To make the objectives, features, and beneficial effects of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is provided with reference to the accompanying drawings. It can be understood that the following described specific embodiments are only for explaining the present invention and are not intended to limit the present invention. Moreover, the same or similar reference numerals may be used in the drawings to refer to the same or similar elements in different embodiments, and the descriptions of the same or similar elements in different embodiments and the descriptions of the elements, features, effects, etc. of the prior art may also be omitted.

[0031] Referring to Figure 1 , an embodiment of the present invention provides a high-speed Raman spectroscopy imaging device.

[0032] Please refer to Figure 1, A high-speed Raman spectroscopic imaging device, at least comprising a laser module 1, a beam splitter 2, an objective lens 3, a translation module 5, a focusing element 6 and a spectrometer 7; the translation module 5, the objective lens 3, the beam splitter 2, the focusing element 6 and the spectrometer 7 are arranged in sequence, a sample 4 is arranged on the translation module 5, and the objective lens 3, the beam splitter 2, the focusing element 6 and the spectrometer 7 form a confocal optical path; the laser module 1 is arranged at a certain angle relative to the beam splitter 2;

[0033] The laser module 1 is used to generate multiple beams of non-parallel lasers;

[0034] The beam splitter 2 reflects the laser emitted by the laser module 1 to the entrance pupil of the objective lens 3 and allows the Raman signal light to penetrate, so as to be collected by the focusing element 6;

[0035] The objective lens 3 focuses multiple beams of non-parallel lasers reflected by the beam splitter 2 to different positions of the sample 4, and collimates the Raman signal light returned from the laser irradiated on the sample into multiple beams of non-parallel Raman signal light;

[0036] The focusing element 6 collects the Raman signal light penetrating the beam splitter 2 into the spectrometer 7 and projects it onto different row pixels of the area array CCD camera of the spectrometer 7 respectively;

[0037] The spectrometer 7 is used to simultaneously collect the Raman spectra at different positions of the sample 4;

[0038] The translation module 5 is used to move the sample 4.

[0039] In some embodiments, the beam splitter 2 is a spectroscopic prism, a flat beam splitter or a dichroic mirror. The beam splitter 2 divides the incident beam into two parts, one part is transmitted through and the other part is reflected.

[0040] In some embodiments, the sample 4 is arranged on the focal plane of the objective lens 3, and the objective lens 3 comprises at least one lens.

[0041] In some embodiments, the translation module 5 comprises at least one displacement stage, and the translation module 5 drives the sample 4 to move on the focal plane of the objective lens 3.

[0042] In some embodiments, the focusing element 6 is at least composed of one or a combination of a convex lens and a concave mirror.

[0043] In some embodiments, the slit of the spectrometer 7 coincides with the rear focal plane of the focusing element 6.

[0044] In some embodiments, the angle of the laser emitted by the laser module 1 is adjustable. By adjusting the incident angle of the laser emitted by the laser module 1 to the beam splitter 2, the acquisition position of the sample 4 for single Raman spectrum acquisition is adjusted.

[0045] In a specific embodiment, the laser module 1 uses a 633 nm narrow linewidth laser as the light source, the beam splitter 2 is a dichroic mirror, the objective lens 3 is a 50x objective lens (focal length 4 mm), the translation module 5 is a two-dimensional electric displacement stage, the focusing element 6 is a convex lens (focal length 40 mm), and the spectrometer 7 uses a high-resolution spectrometer equipped with a thermoelectrically cooled area array CCD. Figure 1 The solid arrows in the figure indicate two beams of laser emitted by the laser module 1 propagating at different angles, and the dashed arrows indicate two beams of Raman signal light returning from different positions of the sample 4; the two beams of laser propagating at different angles represented by the solid arrows are first reflected by the beam splitter 2 and then pass through the objective lens 3, and are focused by the objective lens 3 to two different positions at the sample 4 to generate Raman signal light; subsequently, the generated Raman signal light is collimated by the objective lens 3 into two non-parallel beams of Raman signal light, and the Raman signal light passes through the beam splitter 2 and is focused by the focusing element 6 to different positions of the slit of the spectrometer 7. The connecting direction of the focused light spots is parallel to the grating ruling direction of the spectrometer 7, and is projected onto different rows of the area array CCD camera of the spectrometer 7 through the internal optical path of the spectrometer 7. By collecting the data of the area array CCD camera of the spectrometer once, the Raman spectral information of different excitation positions of the sample 1 is obtained simultaneously;

[0046] Control the translation module 5 to change the position of the sample 4, and continue to collect the Raman spectral data of different positions of the sample 1 to complete Raman spectral imaging.

[0047] In a single Raman signal acquisition, the measurement position of the sample 4 is determined by the incident angle of the laser and the parameters of the objective lens 3. When the objective lens 3 is determined, the measurement position of the sample 4 can be accurately adjusted by adjusting the incident angle of the laser; the relative coordinates (x, y) of the measurement position are expressed as:

[0048] (x, y) = (f0 tanθ x , f0 tanθ y ) (1)

[0049] where f0 is the focal length of the objective lens 3, and θ x and θ y are the lens mappings of the included angles between the incident light and the optical axis of the objective lens 3 on the x-axis and y-axis, respectively;

[0050] The maximum adjustable range of the distance between the measurement position and the optical axis is determined by the focal length f0 of the objective lens 3 parameters and the numerical aperture NA of the objective lens, and does not exceed where n is the refractive index of the medium.

[0051] The focal length f0 of the objective lens 3 = 4 mm, the incident laser consists of two beams of laser propagating at different angles, and the lens mappings of the included angles between the two beams of laser and the optical axis of the objective lens 3 on the x-axis and y-axis are (θ x1 , θ y1 ) = (0, 0) and (θ x1, θ y1 ) = (0.5°, 0). Therefore, the measurement positions are (0, 0) and (35, 0), with the unit being micrometers.

[0052] The focal length f1 of the focusing element 6 is 40 mm. The positions where the Raman signal lights generated by the two measurement positions are focused into the slit are (0, 0) and (350, 0) respectively, with the unit being micrometers. The direction of the line connecting the two is parallel to the grating ruling direction of the spectrometer 7 and perpendicular to the spectral direction of the area array CCD camera of the spectrometer 7; the focal lengths of the two collimating / focusing elements in the spectrometer 7 are the same. Therefore, the Raman signals generated by the two measurement positions in the sample are respectively focused onto different rows of the area array CCD camera of the spectrometer 7, and the center distance between the rows is 350 micrometers.

[0053] In this embodiment, by controlling the translation module 5 to change the position of the sample, Raman spectral data of multiple groups of positions in the sample are measured.

[0054] Figure 2 Shows the Raman spectral imaging diagram of the high-speed Raman spectral imaging device according to the embodiment of the present invention for measuring a silicon wafer with a mark; Figure 2 (a) is the Raman spectral imaging of selecting the Raman characteristic peak of silicon at 520 cm -1 -1, Figure 2 (b) is the bright-field imaging of the sample; the Raman spectral imaging can clearly distinguish different sample regions, which is consistent with the bright-field imaging of the sample; the high-speed Raman imaging can obtain molecular information without staining, and is especially suitable for in-situ analysis and imaging of complex or living samples.

[0055] Figure 3 Shows the Raman spectral imaging diagram of the high-speed Raman spectral imaging system according to the embodiment of the present invention for measuring a quartz glass tube filled with absolute ethanol; Figure 3 (a) is the Raman spectral imaging of selecting the Raman characteristic peak of absolute ethanol at 884 cm -1 -1, Figure 3 (b) is the Raman spectral imaging of selecting the Raman characteristic peak of the quartz glass tube at 608 cm -1 -1. The regions of the quartz glass tube wall and the sample filled with absolute ethanol can be clearly distinguished from the Raman spectral imaging.

[0056] The high-speed Raman spectral imaging system according to the embodiment of the present invention has a faster scanning speed than the traditional Raman spectral imaging, and the scanning speed is increased to 2 times; by adjusting the included angle of the incident light, the spacing of the scanning sites can be controlled, thereby reducing the requirement of the imaging resolution for the accuracy of the translation module and saving and controlling the hardware cost.

[0057] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the disclosure of the present utility model, even when a single embodiment is described only with respect to specific features. The feature examples provided in the disclosure of the present utility model are intended to be illustrative rather than restrictive, unless otherwise stated. In a specific implementation, according to actual needs and where technically feasible, the technical features of one or more dependent claims can be combined with the technical features of the independent claim, and can be obtained from the technical features of the corresponding independent claim by any appropriate means rather than only through the specific combinations listed in the claims.

Claims

1. A high-speed Raman spectroscopic imaging device, characterized in that, It includes at least a laser module, a beam splitter, an objective lens, a translation module, a focusing element and a spectrometer; the translation module, the objective lens, the beam splitter, the focusing element and the spectrometer are arranged in sequence, a sample is arranged on the translation module, and the objective lens, the beam splitter, the focusing element and the spectrometer form a confocal optical path; the laser module is arranged at a certain angle relative to the beam splitter; The laser module is used to generate multiple non-parallel laser beams; The beam splitter reflects the laser emitted by the laser module to the entrance pupil of the objective lens and allows the Raman signal light to penetrate, so as to be collected by the focusing element; The objective lens focuses the multiple non-parallel laser beams reflected by the beam splitter to different positions of the sample and collimates the Raman signal light returned from the laser irradiated on the sample into multiple non-parallel Raman signal beams; The focusing element collects the Raman signal light penetrating the beam splitter into the spectrometer and projects it onto different row pixels of the area array CCD camera of the spectrometer respectively; The spectrometer is used to simultaneously collect Raman spectra at different positions of the sample; The translation module is used to move the sample.

2. The high-speed Raman spectroscopic imaging device according to claim 1, characterized in that, The emission angle of the laser emitted by the laser module is adjustable. By adjusting the incident angle of the laser emitted by the laser module to the beam splitter, the collection position of the sample for single Raman spectrum collection is adjusted.

3. The high-speed Raman spectroscopic imaging device according to claim 1, wherein The beam splitter is a spectroscopic prism, a flat beam splitter or a dichroic mirror. The beam splitter divides the incident light beam into two parts, one part is transmitted and the other part is reflected.

4. The high-speed Raman spectroscopic imaging device according to claim 1, characterized in that The sample is arranged on the focal plane of the objective lens, and the objective lens includes at least one lens.

5. The high-speed Raman spectroscopic imaging device according to claim 1, characterized in that, The translation module includes at least one displacement stage, and the translation module drives the sample to move on the focal plane of the objective lens.

6. The high-speed Raman spectroscopic imaging device according to claim 1, characterized in that, The focusing element is at least composed of one or more combinations of a convex lens and a concave mirror.

7. The high-speed Raman spectroscopic imaging device according to claim 1, characterized in that, The slit of the spectrometer coincides with the rear focal plane of the focusing element.

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