CN118483211B

CN118483211B - Raman spectrum test system and test method based on cascade spectrometer

Info

Publication number: CN118483211B
Application number: CN202410725378.1A
Authority: CN
Inventors: 罗湘雯; 朱剑; 马晖; 储瑞巍; 邹佳宁
Original assignee: Zhongke Kaili Instrument Suzhou Co ltd
Current assignee: Zhongke Kaili Instrument Suzhou Co ltd
Priority date: 2024-06-05
Filing date: 2024-06-05
Publication date: 2025-01-28
Anticipated expiration: 2044-06-05
Also published as: CN118483211A

Abstract

The invention discloses a Raman spectrum testing system and a testing method thereof based on a cascade spectrometer. The test system comprises an excitation unit, a Raman excitation acquisition unit and a spectrum detection unit, wherein the excitation light unit is used for generating excitation light with a plurality of different wavelengths, the excitation light is combined into a beam and then is input into the Raman excitation acquisition unit, the Raman excitation acquisition unit is used for focusing the received excitation light onto a sample to be tested and generating the excitation light, the excitation light and the excitation light are separated and then are input into the spectrum detection unit, and the spectrum detection unit is switched between a first working mode and a second working mode through a detection mode switching mechanism, so that high-sensitivity mode detection, high-resolution mode detection or low-wave number mode detection are respectively realized. According to the invention, the cascaded spectrometers are used for Raman spectrum detection, so that the high-sensitivity mode, the high-resolution detection mode and the low-wave number detection mode are integrated in the same system, and the overall performance of the Raman spectrum system is improved.

Description

Raman spectrum testing system based on cascade spectrometer and testing method thereof

Technical Field

The invention relates to spectrum analysis equipment, in particular to a Raman spectrum test system based on a cascade spectrometer, and belongs to the technical field of instrument testing.

Background

The raman spectroscopy technology is a method for optically detecting the components of a substance, and the nonlinear effect is excited through the interaction of laser and chemical bonds in the molecules of a sample, so that the structural information in the sample is revealed. The raman spectroscopy technology is widely applied to various fields such as material analysis, biomedicine, substance identification and the like as a nondestructive and rapid analysis means.

In raman spectroscopy, resolution and the number of measured waves are the most central technical parameters. The traditional Raman excitation acquisition system adopts a long-wave pass filter to filter laser, but is limited by the initial wavelength of the filter, and Raman signals with low wave numbers can be filtered together and are difficult to detect. And, limited by filter material and membrane layer design, is difficult to be applied to ultraviolet band, and applicable band is narrower. In the existing raman spectrum test technology, although the cascade spectrometer is proposed to realize low wave number measurement, the resolution is low, the measurement mode is single, the application sample detection range is limited, and the application variety is less. Therefore, the existing raman test systems all have the problem of single function, so that the low wave number detection mode and the high resolution detection cannot be integrated in the same system.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a Raman spectrum testing system based on a cascade spectrometer, which solves the problems that the existing Raman spectrum testing device has single function and limited detection sample types.

The invention provides a Raman spectrum testing system based on a cascade spectrometer, which comprises an excitation light unit, a Raman excitation light acquisition unit and a spectrum detection unit, wherein the excitation light unit comprises a plurality of excitation light sources and an excitation light beam combining mechanism, the excitation light sources are used for generating excitation lights with different wavelengths, the excitation light beam combining mechanism is used for combining the excitation lights and inputting the excitation lights into the Raman excitation acquisition unit, the Raman excitation acquisition unit comprises an excitation light focusing mechanism and an excitation light separating mechanism, the excitation light focusing mechanism is used for focusing the received excitation lights on a sample to be tested and generating excited lights, the excitation light separating mechanism is used for separating the excited lights from the excitation lights and then outputting the excited lights to the spectrum detection unit, the spectrum detection unit comprises a plurality of spectrometers, a detection mode switching mechanism and a detection mechanism, the detection mode switching mechanism at least can be switched between a first working mode and a second working mode, when the first working mode is set, the detection mode switching mechanism is used for enabling the received excited lights to enter the detection mechanism after passing through a selected spectrometer, high-sensitivity mode detection is realized, the excited lights are separated from the excitation light beam combining mechanism is used for enabling the received through the second working mode to enter the detection mechanism, and the high-resolution mode detection is realized when the excited light mode is set in the second working mode, and the high-resolution mode is used for enabling the excited light mode to enter the high-resolution detection mode to be sequentially detected after the detection mode.

Further, the excitation light sources are at least used for generating any one or more of deep ultraviolet band excitation light, visible band excitation light and near infrared band excitation light;

further, the excitation light is a narrow linewidth laser suitable for Raman excitation;

Further, the wavelength of the excitation light is 177-1024nm;

Further, the excitation beam combining mechanism comprises a first reflecting mirror group, a lens switching mechanism, a second reflecting mirror group and a lens angle adjusting mechanism, wherein the lens switching mechanism is used for respectively switching a plurality of first reflecting mirrors in the first reflecting mirror group to corresponding working positions, and the lens angle adjusting mechanism is used for respectively adjusting the reflecting angles of a plurality of first reflecting mirrors and a plurality of second reflecting mirrors in the first reflecting mirror group and the second reflecting mirror group, so that a plurality of excitation lights entering the excitation beam combining mechanism sequentially pass through the second reflecting mirror group and the first reflecting mirror group and then are output through the same light output path, and enter the Raman excitation acquisition unit.

Further, the lens switching mechanism comprises a mechanical translation mechanism which is in transmission fit with the first reflector group.

Further, the raman excitation acquisition unit further comprises an excitation light intensity adjusting mechanism, wherein the excitation light intensity adjusting mechanism is used for adjusting the excitation light input into the raman excitation acquisition unit to a set intensity and then transmitting the excitation light to the excitation light focusing mechanism;

further, the excitation light intensity adjusting mechanism comprises a neutral attenuation sheet wheel set, wherein the neutral attenuation sheet wheel set comprises at least one rotating wheel and a plurality of neutral attenuation sheets arranged on the rotating wheel;

Further, the transmittance of the plurality of neutral attenuation sheets is at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, respectively, so that the light intensity is changed within a range of 10-100%;

Further, the neutral attenuation sheet wheel set comprises two rotating wheels, wherein one rotating wheel is provided with neutral attenuation sheets with transmittance of at least 1%, 2%, 5% and 10% respectively, the other rotating wheel is provided with neutral attenuation sheets with transmittance of at least 1%, 10%, 20% and 50% respectively, and the light intensity is changed within a range of 0.01-100% by the combination of the neutral attenuation sheets on the two rotating wheels;

further, the rotating wheel is provided with a driving mechanism for driving the rotating wheel to rotate;

Further, the raman excitation acquisition unit further comprises a confocal assembly, the confocal assembly comprises a first lens and a second lens which are matched with each other, a pinhole is arranged between the first lens and the second lens, the pinhole is located at a common focal point of the first lens and the second lens, the first lens is at least used for focusing excitation light input into the raman excitation acquisition unit to a position of the pinhole, and the second lens is at least used for collimating the excitation light transmitted through the pinhole into parallel light and conveying the parallel light to the excitation light intensity adjusting mechanism.

Further, the excitation light focusing mechanism comprises a third reflecting mirror group and a focusing assembly, wherein the third reflecting mirror group is at least used for reflecting the excitation light transmitted by the excitation light intensity adjusting mechanism to the focusing assembly, and the focusing assembly is at least used for focusing the received excitation light onto a sample to be detected, and the sample to be detected receives the excitation light and excites a Raman signal to generate excited luminescence;

further, the focusing assembly includes an objective lens;

Further, the raman excitation collection unit further comprises a sample accommodating mechanism, wherein the sample accommodating mechanism is used for accommodating a sample to be detected;

Further, the sample accommodating mechanism is arranged on the objective table, and the objective table can move at least in a three-dimensional space so as to realize displacement of a sample to be detected and focusing of laser on the surface of the sample.

Further, the stimulated luminescence separation mechanism comprises a first separation mirror group, and the first separation mirror group is at least used for reflecting the stimulated luminescence into the detection mode switching mechanism;

Further, the first separation mirror group comprises a first separation mirror, a through hole is arranged in the center of the first separation mirror, and a reflecting area is arranged around the through hole, the through hole is at least used for allowing the excitation light to pass through, and the reflecting area is at least used for reflecting the excitation light to the detection mode switching mechanism;

further, the first separation mirror is any one of a dichroic mirror, a long-wave pass filter and a small mirror.

Further, the raman excitation collection unit further comprises an illumination light source module, the illumination light source module comprises a light source assembly, a beam splitter moving mechanism and an illumination detection assembly, the light source assembly is used for generating illumination light, the beam splitter assembly is connected with the beam splitter assembly and at least used for driving the beam splitter assembly to switch between a third working mode and a fourth working mode, when the raman excitation collection unit is in the third working mode, the beam splitter assembly is used for conveying the illumination light to a sample to be detected and generating scattered illumination light, the beam splitter assembly conveys the scattered illumination light to the illumination detection assembly, the illumination detection assembly receives the scattered illumination light and achieves microscopic observation and focusing assistance of the sample to be detected, and when the raman excitation collection light path is in the fourth working mode, the beam splitter assembly moves out of the excitation light and the stimulated luminescence light path to ensure that the raman excitation collection light path is not affected.

Further, the light source assembly comprises a light source, a light homogenizing device and a collimation device, wherein the light source generates illumination light, and the illumination light is sequentially transmitted to the light splitting assembly through the light homogenizing device and the collimation device;

Further, the beam splitting assembly comprises a first beam splitting mirror group and a second beam splitting mirror group, the beam splitting mirror moving mechanism is used for moving a second beam splitting mirror in the second beam splitting mirror group between a first position and a second position, when the beam splitting mirror is positioned at the first position, the beam splitting assembly is positioned in a third working state, the illumination light is sequentially transmitted to the sample to be detected through the first beam splitting mirror group and the second beam splitting mirror group, the scattered illumination light is sequentially transmitted to the illumination detection assembly through the second beam splitting mirror group and the first beam splitting mirror group, when the beam splitting mirror is positioned at the second position, the beam splitting assembly is positioned in a fourth working state, and the second beam splitting mirror is moved out of the optical paths of the excitation light and the excited light;

Further, the first spectroscopic group includes a first spectroscopic lens having a lens inverse ratio of 10:90,20:80,30:70,40:60,50:50,60:40,70:30,80:20,90:10, with 50:50 being preferred;

further, the first light-splitting lens is any one of a light-splitting prism, a light-splitting flat sheet, a light-splitting wafer and a light-splitting ellipse;

Further, the inverse ratio of the lenses of the second beam-splitting lenses is 10:90,20:80,30:70,40:60,50:50,60:40,70:30,80:20,90:10, with 10:90 being preferred;

further, the second light splitting lens is a light splitting prism;

Further, the illumination detection assembly comprises an illumination detector, a linear polaroid and a lens group, wherein scattered illumination light is sequentially transmitted to the illumination detector through the linear polaroid and the lens group, the linear polaroid at least improves the contrast ratio of illumination imaging through rotary extinction, the lens group at least images the scattered illumination light on the illumination detector, and the illumination detector is used for microscopic observation and focusing assistance of a sample to be detected;

Further, the lens group is an aberration-eliminating design lens group;

Further, the illumination detector is one or a combination of a camera and an eyepiece.

Further, the detection mode switching mechanism comprises a fourth reflecting mirror group and a lens moving mechanism, wherein the lens moving mechanism is used for switching a fourth reflecting mirror in the fourth reflecting mirror group between a third position and a fourth position, when the detection mode switching mechanism is positioned at the third position, the detection mode switching mechanism is positioned in a first working mode, and when the detection mode switching mechanism is positioned at the fourth position, the detection mode switching mechanism is positioned in a second working mode;

Further, the detection mode switching mechanism further comprises a first focusing element and a second focusing element, in the first working mode, the fourth reflecting mirror reflects the stimulated luminescence to the first focusing element, the first focusing element focuses and conveys the stimulated luminescence to the corresponding spectrometer, in the second working mode, the fourth reflecting mirror moves out of the optical path, and the second focusing element focuses and conveys the stimulated luminescence to the corresponding spectrometer;

further, the first focusing element comprises any one of an off-axis parabolic mirror, a convex lens and a concave spherical reflector;

Further, the second focusing element comprises any one of an off-axis parabolic mirror, a convex lens and a concave spherical mirror.

The invention also provides a Raman spectrum testing method, which is implemented based on the Raman spectrum testing system, and comprises the following steps:

The excitation light beams with different wavelengths generated in the excitation light unit are transmitted to the Raman excitation acquisition unit;

the excitation light entering the Raman excitation acquisition unit is focused on a sample to be detected, excitation light is generated, and the excitation light are separated and then are transmitted to the spectrum detection unit;

The working mode of the detection mode switching mechanism is adjusted, so that the stimulated luminescence entering the spectrum detection unit enters the detection mechanism after passing through a selected spectrometer to realize high-sensitivity mode detection, or the stimulated luminescence entering the spectrum detection unit enters the detection mechanism after passing through a plurality of spectrometers in sequence to realize high-resolution mode or low-wave number mode detection.

Further, the stimulated luminescence entering the spectrum detection unit sequentially passes through a plurality of spectrometers, wherein each spectrometer has a light splitting function, so that a signal spectrum is cascaded and amplified by the plurality of spectrometers and then enters a detection mechanism to obtain a high-resolution spectrum, and high-resolution mode detection is realized;

Or a plurality of spectrometers are respectively defined as a first spectrometer, a second spectrometer and a third spectrometer, wherein the first spectrometer and the third spectrometer have a light splitting function, the second spectrometer has a light combining function and can prevent the excitation light from passing through, and the excited light entering the spectrum detection unit sequentially passes through the first spectrometer, the second spectrometer and the third spectrometer and then enters the detection mechanism, so that the low wave number mode detection is realized.

Compared with the prior art, the Raman spectrum testing system based on the cascade spectrometer provided by the invention has the advantages that the cascade spectrometer is used for Raman spectrum detection, the resolution is improved, the low wave number starting measurement is realized, the overall performance of the Raman spectrum system is improved, and the single detection mode, the high-resolution detection mode and the low wave number detection mode are integrated in the same system through the cooperation of cascade amplification, light splitting and light combining among a plurality of spectrometers.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to the drawings without inventive effort to those skilled in the art.

FIG. 1 is a schematic top view of a cascaded spectrometer-based Raman spectrum testing system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the working principle of a Raman spectrum testing system based on a cascade spectrometer according to an embodiment of the present invention;

FIG. 3 is a schematic top view of an excitation light unit according to an embodiment of the present invention;

FIG. 4 is a schematic diagram showing a front view of an excitation light unit according to an embodiment of the present invention;

FIG. 5 is a schematic diagram showing a left-hand structure of an excitation light unit according to an embodiment of the present invention;

FIG. 6 is a schematic top view of a Raman excitation acquisition unit according to an embodiment of the present invention;

FIG. 7 is a schematic diagram showing a front view of a Raman excitation acquisition unit according to an embodiment of the present invention;

FIG. 8 is a schematic top view of a spectrum sensing unit according to an embodiment of the invention;

FIG. 9 is a schematic diagram of the high resolution detection mode operation of the spectral detection unit in one embodiment of the present invention;

FIG. 10 is a schematic diagram of the low wave number detection mode operation of the spectral detection unit in one embodiment of the present invention;

FIG. 11 is a schematic diagram of a confocal assembly according to an embodiment of the invention.

Detailed Description

In view of the shortcomings in the prior art, the inventor of the present invention has long studied and practiced in a large number of ways to propose the technical scheme of the present invention. The technical scheme, the implementation process, the principle and the like are further explained as follows.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.

In addition, in the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "horizontal", "vertical", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present specification, reference to the term "one embodiment," "an embodiment," "the embodiment," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Referring to fig. 1-11, the invention provides a raman spectrum testing system based on a cascade spectrometer, which comprises an excitation light unit, a raman excitation acquisition unit and a spectrum detection unit, wherein the excitation light unit comprises a plurality of excitation light sources and an excitation light beam combining mechanism, the plurality of excitation light sources are used for generating excitation lights with different wavelengths, the excitation light beam combining mechanism is used for combining the excitation lights and inputting the excitation lights into the raman excitation acquisition unit, the raman excitation acquisition unit comprises an excitation light focusing mechanism and an excitation light separating mechanism, the excitation light focusing mechanism is used for focusing the received excitation lights onto a sample 14 to be tested and generating excited lights, the excitation light separating mechanism is used for separating the excited lights from the excited lights and then outputting the separated excitation lights to the spectrum detection unit, the spectrum detection unit comprises a plurality of spectrometers, a detection mode switching mechanism and a detection mechanism, the detection mode switching mechanism at least can be switched between a first working mode and a second working mode, when the first working mode is in the first working mode, the detection mode switching mechanism is used for enabling the received excited lights to enter the detection mechanism after passing through a selected spectrometer, and high-sensitivity mode detection is achieved, when the detection mechanism is in the second working mode, the detection mode is used for enabling the excited lights to enter the high-resolution mode to be detected by the multiple spectrometers after the detection mode. The multiple excitation light sources are at least used for generating one or more of deep ultraviolet band excitation light, visible band excitation light and near infrared band excitation light.

In one embodiment, the excitation light unit is provided with three excitation light sources capable of respectively emitting different wavelengths, including a first excitation light source 100, a second excitation light source 200 and a third excitation light source 300, wherein the first excitation light source 100 can generate deep ultraviolet band excitation light, the second excitation light source 200 can generate visible band excitation light, the third excitation light source 300 can generate near infrared band excitation light, raman excitation of ultraviolet and infrared bands can effectively avoid fluorescence interference, signal to noise ratio of raman signals is improved, and in addition, since the excitation intensity of raman signals is inversely proportional to four times of wavelength, deep ultraviolet laser is utilized to help to enhance raman signals, which is very beneficial to weak signal detection. The wavelength range of the Raman excitation light is 177-1024nm. Because the three excitation light sources are positioned at different positions, the excitation light at different positions generated by the three excitation light sources is output to the Raman excitation acquisition unit from the same path through the excitation light beam combining mechanism, so that the Raman excitation acquisition unit is convenient to receive the excitation light. Then, the excitation light focusing mechanism in the raman excitation unit conveys the received excitation light to the sample 14 to be detected after focusing, the excitation light irradiates the sample 14 to be detected, so that a raman signal of the sample 14 to be detected is excited, the sample 14 to be detected generates excitation light, the generated excitation light is collimated and returned to the excitation light separating mechanism, the excitation light separating mechanism separates the excitation light from the excitation light, and the excitation light is conveyed to the spectrum detection unit.

In this embodiment, the spectrum detection unit includes three spectrometers, and can perform two modes of detection on the stimulated luminescence reflected by the sample 14 to be detected, where in the first detection mode, the detection mode switching mechanism is in the first working mode, and the detection mode switching mechanism receives the stimulated luminescence transmitted by the stimulated luminescence separation mechanism and enters the detection mechanism after passing through the third spectrometer 28, so as to implement high-sensitivity mode detection, where the sensitivity of the high-sensitivity mode detection is higher, a stronger raman signal can be obtained, and the spectrum detection unit is suitable for samples with weaker detection signals. In the second detection mode, the detection mode switching mechanism is in the second working mode, and the detection mode switching mechanism receives the stimulated luminescence transmitted by the stimulated luminescence separation mechanism and enters the detection mechanism through the first spectrometer 26, the second spectrometer 27 and the third spectrometer 28 to realize detection in a high resolution mode or in a low wave number mode, wherein the high resolution mode can obtain spectral data with higher resolution, and the low wave number mode can detect a Raman signal with low wave number to obtain the sample structure and component information in the low wave number region.

In addition, the excitation light is a narrow linewidth laser suitable for raman excitation, and includes a narrow-band filter of a corresponding wavelength.

In the specific structure of the excitation light combining mechanism, the excitation light combining mechanism comprises a first reflecting mirror group, a lens switching mechanism 7, a second reflecting mirror group and a lens angle adjusting mechanism, wherein the lens switching mechanism is used for respectively switching a plurality of first reflecting mirrors in the first reflecting mirror group to corresponding working positions, and the lens angle adjusting mechanism is used for respectively adjusting the reflecting angles of a plurality of first reflecting mirrors and a plurality of second reflecting mirrors in the first reflecting mirror group and the second reflecting mirror group so that a plurality of excitation lights entering the excitation light combining mechanism sequentially pass through the second reflecting mirror group and the first reflecting mirror group and then are output through the same light output path, and enter the Raman excitation acquisition unit. The lens switching mechanism comprises a mechanical translation mechanism which is in transmission fit with the first reflecting mirror group.

In one embodiment, the first reflecting mirror group includes three first reflecting mirrors, which correspond to the first excitation light source, the second excitation light source and the third excitation light source respectively, the lens switching structure includes a mechanical translation mechanism, the first reflecting mirror group may be disposed on the mechanical translation mechanism, and the three first reflecting mirrors are made to be in corresponding working states respectively through the translation of the mechanical translation mechanism along a straight line, and the second reflecting mirror group includes at least three second reflecting mirrors, which correspond to the three first reflecting mirrors one by one, where, for better reflection excitation light, the second reflecting mirror group is in transmission fit with the lens angle adjusting mechanism, so that the lens angle adjusting mechanism adjusts the reflection angle of the second reflecting mirror and the reflection angle of the first reflecting mirror in the first reflecting mirror group according to the position of the excitation light generated by the three excitation light sources. The mechanical translation mechanism can be an electric translation table or a motor and screw rod structure, and is convenient to control and move.

In the specific structure of the raman excitation acquisition unit, the raman excitation acquisition unit further comprises an excitation light intensity adjusting mechanism, wherein the excitation light intensity adjusting mechanism is used for adjusting the excitation light input into the raman excitation acquisition unit to a set intensity and then transmitting the excitation light to the excitation light focusing mechanism.

In one embodiment, the excitation light intensity adjustment mechanism includes a neutral-section wheel set 10 including at least one wheel and a plurality of neutral-section sections provided on the wheel. Wherein the transmittance of the plurality of neutral attenuation sheets is at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, respectively, so that the light intensity is changed within a range of 10-100%.

In another embodiment, the neutral attenuation sheet wheel set 10 comprises two rotating wheels, wherein one rotating wheel is provided with neutral attenuation sheets with transmittance of at least 1%, 2%, 5% and 10% respectively, and the other rotating wheel is provided with neutral attenuation sheets with transmittance of at least 1%, 10%, 20% and 50% respectively, and the light intensity is changed within a range of 0.01-100% by combining the neutral attenuation sheets on the two rotating wheels.

Wherein, the runner is equipped with the actuating mechanism that drives it to rotate.

The rotating wheel is driven to rotate by the driving mechanism so as to replace neutral attenuation sheets with different transmittance, and the degree of attenuation of the light intensity of the received excitation light according to the required requirement is realized. Or set up two runners, be provided with the neutral attenuation piece that a plurality of transmissivity are different on every runner, this two runners are along the range upon range of setting of light path advancing direction, and these two runners can rotate alone, when using, can rotate these two runners respectively as required for the neutral attenuation piece of different transmissivity on this two runners makes up, makes the excitation light pass through two neutral attenuation pieces of above-mentioned combination in proper order, realizes the regulation to the light intensity of excitation light.

In addition, the raman excitation acquisition unit further comprises a confocal assembly, the confocal assembly comprises a first lens 31 and a second lens 33 which are matched with each other, a pinhole 32 is arranged between the first lens 31 and the second lens 33, the pinhole 32 is located at a common focal point of the first lens 31 and the second lens 33, the first lens 31 is at least used for focusing the excitation light input into the raman excitation acquisition unit to the position of the pinhole 32, and the second lens 33 is at least used for collimating the excitation light transmitted through the pinhole 32 into parallel light and transmitting the parallel light to the excitation light intensity adjusting mechanism.

In one embodiment, as shown in fig. 11, before the excitation light passes through the excitation light intensity adjusting mechanism, a confocal assembly is disposed on the optical path of the excitation light, wherein the confocal assembly includes a first lens 31, a second lens 33, and a pinhole 32 between the first lens 31 and the second lens 33, the excitation light passes through the first lens 31, the first lens 31 focuses the excitation light at the pinhole 32, the focused excitation light is sent to the second lens 33 through the pinhole 32, the second lens 33 collimates the excitation light to form parallel light, and the parallel light is sent to the excitation light intensity adjusting mechanism. The confocal assembly is used for shaping the excitation light beam, so that the size of the excitation light focusing light spot is reduced, the rapidly-divergent focusing light spot is formed, and the transverse and axial resolutions of the Raman spectrum system are improved.

Or in another embodiment, the confocal assembly may also be placed after the excitation light intensity adjustment mechanism.

In the specific structure of the excitation light focusing mechanism, the excitation light focusing mechanism comprises a third reflecting mirror group and a focusing assembly, wherein the third reflecting mirror group is at least used for reflecting the excitation light transmitted by the excitation light intensity adjusting mechanism to the focusing assembly, and the focusing assembly is at least used for focusing the received excitation light onto the sample 14 to be detected, and the sample 14 to be detected receives the excitation light and excites a Raman signal and generates excited luminescence. The focusing assembly comprises an objective lens 13.

In one embodiment, the third mirror group includes at least one third mirror 11 to adjust the transmission path of the excitation light to be delivered to the objective lens 13. In another embodiment, the focusing assembly includes an object lens disc and a plurality of objective lenses 13, the plurality of objective lenses 13 are mounted on the object lens disc, and the objective lens disc can be rotated to switch the plurality of objective lenses 13.

In addition, the raman excitation collection unit further comprises a sample accommodating mechanism 15, wherein the sample accommodating mechanism 15 is used for accommodating the sample 14 to be measured. The sample receiving mechanism 15 is disposed on a stage that is movable in at least three dimensions, the movement of the stage effecting displacement of the sample and focusing of the laser light on the sample surface.

In one embodiment, the sample receiving mechanism 15 may be an electric displacement table, a manual displacement table, a cuvette, or an in-situ cell, and the test system of the present application is designed to irradiate the sample with a laser beam downward, and is suitable for measuring samples in various states such as solid block, powder, liquid, and gas. The sample-holding platform is movable in three dimensions to achieve a focusing function for the sample 14 to be tested.

The stimulated luminescence separation mechanism includes a first separation mirror group at least for reflecting stimulated luminescence into the detection mode switching mechanism. The first separating mirror group comprises a first separating mirror 12, a through hole is arranged in the center of the first separating mirror 12, and a reflecting area is arranged around the through hole, the through hole is at least used for passing the excitation light, and the reflecting area is at least used for reflecting the excitation light to the detection mode switching mechanism. The first separation mirror 12 is any one of a dichroic mirror, a long-pass filter, and a small mirror.

In the present embodiment, the first separation mirror group includes a first separation mirror 12, the first separation mirror 12 is disposed on a transmission path of the excitation light and the excitation light, and a through hole is provided in a middle portion of the first separation mirror 12 for the excitation light to pass therethrough, and the excitation light is reflected to the detection mode switching mechanism through a reflection area of the first separation mirror 12 after being transmitted to the first separation mirror 12, thereby separating the excitation light and the excitation light.

The Raman excitation acquisition unit further comprises an illumination light source module, the illumination light source module comprises a light source assembly, a beam splitting assembly, a beam splitter moving mechanism and an illumination detection assembly, the light source assembly is used for generating illumination light, the beam splitter moving mechanism is connected with the beam splitting assembly and at least used for driving the beam splitting assembly to switch between a third working mode and a fourth working mode, when the beam splitting assembly is in the third working mode, the beam splitting assembly is used for conveying the illumination light to the sample 14 to be detected and generating scattered illumination light, the beam splitting mode switching mechanism conveys the scattered illumination light to the illumination detection assembly, the illumination detection assembly receives the scattered illumination light and achieves microscopic observation and focusing assistance of the sample 14 to be detected, and when the beam splitting assembly is in the fourth working mode, the beam splitting assembly moves out of an excitation light path and an excited light path so as to ensure that the Raman excitation acquisition path is not affected.

The light source assembly comprises a light source 20, a light homogenizing device and a collimation device, wherein the light source 20 generates illumination light, and the illumination light is sequentially transmitted to the light splitting assembly through the light homogenizing device and the collimation device. The light source 20 is a white light LED light source, the light homogenizing device is a group of shaping elements, ground glass can be selected, and the collimating device is a lens or a lens group and is used for converting the output light source into parallel light.

The beam splitting assembly comprises a first beam splitting mirror group and a second beam splitting mirror group, the beam splitting mirror moving mechanism is used for moving a second beam splitting mirror 25 in the second beam splitting mirror group between a first position and a second position, when the beam splitting mirror is located at the first position, the beam splitting assembly is located in a third working state, illumination light is sequentially transmitted to the sample 14 to be detected through the first beam splitting mirror group and the second beam splitting mirror group, scattered illumination light is sequentially transmitted to the illumination detection assembly through the second beam splitting mirror group and the first beam splitting mirror group, when the beam splitting mirror is located at the second position, the beam splitting mirror assembly is located in a fourth working state, and the second beam splitting mirror moves out of the exciting light and the light path of the exciting light.

In one embodiment, before the raman spectrum test is performed on the sample 14 to be tested, the position of the sample 14 to be tested is detected by the illumination light source module, the sample 14 to be tested is illuminated by illumination light, the sample 14 to be tested is imaged, the illumination detection assembly can be used for directly observing the sample 14 to be tested, the sample is adjusted to a proper focusing position by observing the imaging and moving the stage up and down, and the region of interest of the sample 14 to be tested can be moved to the excitation light focusing spot position by horizontally moving the stage.

Specifically, when the sample 14 to be measured needs to be observed, the light source is controlled to generate illumination light, the illumination light sequentially passes through the light homogenizing device and the collimating device, the illumination light is processed by the light homogenizing device to be more uniform, the collimation is processed by the collimating device to form parallel light, then the light splitting mode switching mechanism is controlled to move the second light splitting lens to the first position, the illumination light is emitted from the light source assembly and sequentially passes through the first light splitting lens and the second light splitting lens to irradiate the sample 14 to be measured, and scattered illumination light is generated, and then the scattered illumination light is re-collimated and returned and sequentially passes through the second light splitting lens and the first light splitting lens to enter the illumination detection assembly, so that the sample 14 to be measured can be observed in the illumination detection assembly.

In addition, when the second spectroscope is positioned at the first position, the excitation light unit is turned on at the moment, so that the excitation light is focused on the sample to be detected, and the focusing of the illumination light and the excitation light can be observed in the illumination detection assembly at the same time through the reflection of the second spectroscope and the first spectroscope group, thereby being beneficial to the focusing of the excitation light and the sample to be detected 14 and playing a role of focusing assistance.

Since the second dichroic mirror is required to reflect illumination light, scatter illumination light, excitation light, and excitation light when observing a sample to be measured and performing auxiliary focusing, the second dichroic mirror is in the optical paths of the excitation light and the excitation light, and when raman signal spectrum detection is required, the second dichroic mirror affects the efficiency of raman signal collection, and therefore when raman signal spectrum detection is required to be performed on the sample to be measured 14, the dichroic mode switching mechanism is controlled to move the second dichroic mirror to the second position where the second dichroic mirror moves out of the optical paths of the excitation light and the excitation light.

The first spectroscopic group includes a first spectroscopic lens 21, and the lens ratio of the first spectroscopic lens 21 is 10:90,20:80,30:70,40:60,50:50,60:40,70:30,80:20,90:10, with 50:50 being preferred.

The first spectroscopic lens 21 is any one of a spectroscopic prism, a spectroscopic flat, a spectroscopic wafer, and a spectroscopic ellipse.

The inverse transmittance of the second dichroic mirror 25 is 10:90,20:80,30:70,40:60,50:50,60:40,70:30,80:20,90:10, with 10:90 being preferred.

The second spectroscopic lens 25 is a spectroscopic prism.

In one embodiment, the inverse ratio of the first dichroic mirror 21 to the transmission is 50:50, where the contrast of the illumination detection is highest. The transmissivity of the second light splitting lens should be low so as to be convenient for attenuating the transmitted excitation light and not damaging the illumination detection assembly, and the reflectivity of the second light splitting lens should be high so as to improve the reflectivity of illumination light and improve the brightness of illumination imaging, so that the second light splitting lens selects the transmission ratio of 10:90.

The illumination detection assembly comprises an illumination detector 24, a linear polaroid 22 and a lens group 23, scattered illumination light is sequentially transmitted to the illumination detector 24 through the linear polaroid 22 and the lens group 23, the linear polaroid 22 improves the contrast ratio of illumination imaging at least through rotation extinction, the lens group 23 images the scattered illumination light on the illumination detector 24, and the illumination detector 24 is used for microscopic observation and focusing assistance of a sample 14 to be detected.

The lens group 23 is a aberrations-eliminating design lens group.

The illumination detector 24 is one or a combination of a camera, an eyepiece.

The lighting unit also comprises a human eye safety component, which can be realized through light path design and also can be realized through a laser router.

In one embodiment, an eye-safe illumination light path may be used instead of the illumination light path in this example. The eye safety light path separates the ocular lens from the camera light path, so that laser can not enter the ocular lens under any condition, and the safety of an operator is ensured. The eye-safe optical path is a prior art, and specific structure can be referred to the details described in the patent document with publication number CN 220854654U.

In another embodiment, a laser beam splitter may be further disposed, where the laser beam splitter is a light blocking sheet and is disposed in the excitation light path before or after the excitation light intensity adjusting mechanism. Switching of the passing/shielding of the excitation light can be achieved by controlling the on/off thereof. The first implementation method is that when the eyes are required to observe, the eyepiece cover is opened, and the laser cutter is automatically closed. In the implementation method II, before the second light-splitting lens 25 moves into the light path, the system control software pops up a safety prompt, and after the state of the switch of the router is confirmed by manually clicking, the second light-splitting lens 25 moves into the light path. .

The detection mode switching mechanism comprises a fourth reflecting mirror group and a lens moving mechanism, wherein the lens moving mechanism is used for switching the fourth reflecting mirror 17 in the fourth reflecting mirror group between a third position and a fourth position, when the detection mode switching mechanism is in the third position, the detection mode switching mechanism is in a first working mode, and when the detection mode switching mechanism is in the fourth position, the detection mode switching mechanism is in a second working mode. The detection mode switching mechanism further includes a first focusing member to which the fourth reflecting mirror 17 reflects the stimulated emission light, and a second focusing member to which the fourth reflecting mirror 17 moves out of the optical path, the first focusing member delivering the stimulated emission light to the corresponding spectrometer, and the second focusing member delivering the stimulated emission light to the corresponding spectrometer.

In one embodiment, the lens moving mechanism comprises a moving platform, a motor and a screw rod, wherein the fourth reflecting mirror is arranged on the moving platform, the moving platform is connected with the screw rod and can move relatively, and the motor is connected with the screw rod in a transmission way and drives the screw rod to rotate, so that the moving platform is driven to move. The fourth reflecting mirror 17 is an elliptical reflecting mirror, and the elliptical reflecting mirror can fully utilize the light-transmitting aperture of the raman signal to reflect the raman signal. In the first working mode, the lens moving mechanism drives the fourth reflecting mirror 17 to move to a third position, the fourth reflecting mirror 17 is located on the light path of the stimulated luminescence, the fourth reflecting mirror 17 reflects the stimulated luminescence to the first focusing element, and the stimulated luminescence is transmitted to a selected spectrometer through the first focusing element and then enters the detecting mechanism, so that high-sensitivity mode detection is achieved. In the second working mode, the lens moving mechanism drives the fourth reflecting mirror 17 to move to a fourth position, and in the fourth position, the fourth reflecting mirror 17 moves out of the light path of the stimulated luminescence, so that the stimulated luminescence passes through the first separating mirror 12, then sequentially passes through a plurality of spectrometers through reflection of the second focusing member and enters the detecting mechanism, and detection of a high resolution mode or a low wave number mode is realized.

In addition, the detection mode switching mechanism further includes a filtering unit, which is disposed between the fourth reflecting mirror 17 and the first focusing element, and includes at least three long-wave pass filters corresponding to the wavelength excited by the excitation module, so as to filter the excitation light and transmit the raman signal. In raman spectroscopy systems, the use of a long pass filter instead of the first separating mirror 12 is a relatively common optical path design, but such a design is not suitable for deep ultraviolet bands due to the limitations of the filter. Therefore, the invention adopts the first separating mirror 12 to replace a filter plate as a light path separating element, thereby realizing Gao Xiaola Mansignal detection of the deep ultraviolet band. In low wavenumber mode, no long pass filter is required. In the high sensitivity mode, as in the conventional raman spectroscopy system, at least three long-pass filters need to be disposed between the fourth mirror 17 and the first focusing element to filter out the excitation light.

The first focusing element is any one of an off-axis parabolic mirror, a convex lens and a concave spherical reflector.

The second focusing element is any one of an off-axis parabolic mirror, a convex lens and a concave spherical reflector.

The invention also provides a Raman spectrum testing method, which is characterized in that the testing method is implemented based on a Raman spectrum testing system, and the method comprises the following steps:

The excitation light entering the Raman excitation acquisition unit is focused on the sample 14 to be detected to generate excitation light, and the excitation light are separated and then are transmitted to the spectrum detection unit;

Specifically, stimulated luminescence entering the spectrum detection unit sequentially passes through a plurality of spectrometers, wherein each spectrometer has a light splitting effect, so that a signal spectrum is cascaded and amplified by the plurality of spectrometers and then enters a detection mechanism to obtain a high-resolution spectrum, and high-resolution mode detection is realized;

Or the plurality of spectrometers are respectively defined as a first spectrometer, a second spectrometer and a third spectrometer, wherein the first spectrometer and the third spectrometer have a light splitting function, the second spectrometer has a light combining function and can prevent the passage of excitation light, and the excited light entering the spectrum detection unit sequentially passes through the first spectrometer, the second spectrometer and the third spectrometer and then enters the detection mechanism, so that the low wave number mode detection is realized.

Examples:

Referring to fig. 1-10, the testing system of the present application only takes the third spectrometer as an example to install the CCD, and may also install the CCD or PMT on the first spectrometer and the second spectrometer to obtain more detection modes. If the first spectrometer is also equipped with a CCD, only the first CCD may be used. If the second spectrometer is also provided with a CCD, only the second spectrometer or a sub-high resolution detection mode in which the first spectrometer and the second spectrometer both play a spectroscopic role can be used.

The raman spectrum testing system based on the cascade spectrometer in the above embodiment tests raman signals excited by wavelengths 1, 2 and 3 excited by an excitation source, and the working steps are as follows:

when the control module instructs the first excitation light source 100 to excite the wavelength 1, the lens switching mechanism 7 switches the first mirror 7-1 in the first mirror group corresponding to the wavelength 1 to the working position, and the wavelength 1 is reflected by the second mirror 4 and the first mirror 7-1 in the second mirror group in sequence and enters the raman excitation acquisition unit.

When the control module instructs the second excitation light source 200 to excite the wavelength 2, the lens switching mechanism 7 switches the first reflecting mirror 7-2 corresponding to the wavelength 2 to the working position, and the wavelength 2 is reflected by the second reflecting mirrors 5 and 9 and the first reflecting mirror 7-2 in sequence and enters the raman excitation acquisition unit.

When the control module instructs the third excitation light source 300 to excite the wavelength 3, the lens switching mechanism 7 switches the first reflecting mirror 7-3 corresponding to the wavelength 3 to the working position, and the wavelength 3 is reflected by the second reflecting mirrors 6 and 8 and the first reflecting mirror 7-3 in sequence and enters the raman excitation acquisition unit.

The wavelengths 1,2 and 3 can be input to the Raman excitation acquisition unit along the same path after passing through the excitation light beam combining mechanism.

The control module instructs the neutral attenuation lens wheel set 10 to adjust the transmitted laser light intensity to be consistent with the set value, the laser (namely the wavelength) is folded down through the third reflection lens 11, enters the objective lens 13 through the through hole in the center of the first separation lens 12, and the excitation light is focused on the sample 14 to be detected by the objective lens 13 to excite the Raman signal. If the focusing of the sample 14 to be measured is inaccurate, the control module can adjust the sample accommodating mechanism 15 to adjust the focusing.

The illumination light source 20 is instructed to be turned on by the control module, and the emitted illumination light is transmitted through the first beam splitter lens 21, reflected downwards by the second beam splitter lens 25, enters the objective lens 13, and irradiates the sample 14 to be measured. The illumination light scattered by the sample 14 to be measured is collimated and returned by the objective lens 13, reflected by the second beam splitter lens 25 and the first beam splitter lens 2, passes through the linear polarizer 22 and the lens group 23, and enters the illumination detector 24.

The beam splitter moving mechanism moves the first beam splitter lens 25 to the first position, and the illumination light is reflected by the first beam splitter lens 25, so that the illumination light can be observed and focusing is assisted. If the laser is turned on at this time, focusing of the illumination light and the laser light can be observed at the same time.

The first spectroscopic lens 25 is moved to the second position, and the first spectroscopic lens 25 is moved out of the optical path, which is in raman signal detection mode.

The raman signal light scattered by the sample 14 to be measured is collimated back by the objective lens 13 and reflected by the first separation mirror 12. There are two signal detection paths:

One is used for guiding Raman signal light into the first spectrometer 26, the signal light sequentially passes through the first spectrometer 26, the second spectrometer 27 and the third spectrometer 28, and enters a CCD (charge coupled device) on the third spectrometer 28 for detection;

the other one directs the raman signal light directly into the third spectrometer 28 and into the CCD on the third spectrometer 28 for detection.

The test system of the application has three signal detection modes, namely a single mode, a high resolution mode and a low wave number mode.

The lens moving mechanism is instructed by the control module to switch the fourth mirror 17 between the third position and the fourth position:

When the fourth reflecting mirror 17 is located at the third position, the raman signal light scattered by the sample 14 to be measured is reflected by the first separating mirror 12, reflected by the fourth reflecting mirror 17, reflected and focused by the filter wheel 18, reflected and focused by the off-axis parabolic mirror 19, and enters the entrance slit of the third spectrometer 28.

When the fourth reflecting mirror 17 is located at the fourth position, the fourth reflecting mirror 17 moves out of the optical path, the raman signal light scattered by the sample 14 to be measured is reflected by the first separating mirror 12, reflected and focused by the second off-axis parabolic mirror 16, and enters the entrance slit of the first spectrometer 26.

The single mode corresponds to the optical path of the fourth mirror 17 in the third position, and the signal light is focused by reflection off the off-axis parabolic mirror 19 and enters the entrance slit of the third spectrometer 28 directly.

The high resolution mode and the low wavenumber mode correspond to the optical path when fourth mirror 17 is in the fourth position, and the signal light is focused by reflection from off-axis parabolic mirror two 16 and enters the entrance slit of first spectrometer 26.

In the high-resolution mode, the three spectrometers 26, 27 and 28 all play a role in light splitting, and the signal spectrum is amplified by cascading of the three spectrometers, so that the signal spectrum enters the detection mechanism after being amplified by cascading of the plurality of spectrometers, a high-resolution spectrum is obtained, high-resolution mode detection is realized, and a high-resolution spectrum line is obtained.

In the low wave number mode, a triple spectrometer is adopted, the first spectrometer 26 and the third spectrometer 28 play a role in light splitting, the second spectrometer 27 plays a role in light combining, light scattered by the first spectrometer 26 is recombined into a beam, and the beam enters a slit of the third spectrometer 28. In this mode, the spectral resolution of the system corresponds to the resolution of the third spectrometer 28. The low wave number mode utilizes the entrance slit of the second spectrometer 27 to block the excitation laser, so that the Raman signal passes through, the filtering function is realized, the laser spectral line can be filtered more accurately, and the detection of the low wave number Raman signal is realized.

In one embodiment, a single focal length 750 spectrometer with a grating of 1800g/mm, a slit of 10 μm, a resolution of 0.01nm when measured at 500nm wavelength, and a triple focal length 750 spectrometer with a cascade amplification with a grating of 1800g/mm, a slit of 10 μm, a resolution of 0.0033nm when measured at 500nm wavelength.

The various aspects, embodiments, features and examples of the invention are to be considered in all respects as illustrative and not intended to limit the invention, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

In addition, the inventors have conducted experiments with other materials, process operations, and process conditions as described in this specification with reference to the foregoing examples, and have all obtained desirable results.

While the invention has been described with reference to an illustrative embodiment, it will be understood by those skilled in the art that various other changes, omissions and/or additions may be made and substantial equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.

Claims

1. A cascade spectrometer-based raman spectrum testing system, comprising:

The excitation light unit comprises a plurality of excitation light sources and an excitation light beam combining mechanism, wherein the plurality of excitation light sources are used for generating excitation light with a plurality of different wavelengths, and the excitation light beam combining mechanism is used for inputting the plurality of excitation light beams into the Raman excitation acquisition unit;

the Raman excitation acquisition unit comprises an excitation light focusing mechanism and an excitation light separating mechanism, wherein the excitation light focusing mechanism is used for focusing received excitation light on a sample to be detected and generating excitation light, and the excitation light separating mechanism is used for separating the excitation light from the excitation light and then transmitting the separated excitation light to the spectrum detection unit;

The spectrum detection unit comprises a plurality of spectrometers, a detection mode switching mechanism and a detection mechanism, wherein the detection mode switching mechanism at least can be switched between a first working mode and a second working mode, when the spectrum detection unit is in the first working mode, the detection mode switching mechanism is used for enabling received stimulated luminescence to enter the detection mechanism after passing through a selected spectrometer and realizing high-sensitivity mode detection, and when the spectrum detection unit is in the second working mode, the detection mode switching mechanism is used for enabling the received stimulated luminescence to enter the detection mechanism after passing through the spectrometers in sequence and realizing high-resolution mode or low-wave number mode detection;

the lens switching mechanism is used for respectively switching a plurality of first reflectors in the first reflector group to corresponding working positions, and the lens angle adjusting mechanism is used for respectively adjusting the reflection angles of a plurality of first reflectors and a plurality of second reflectors in the first reflector group and the second reflector group so that a plurality of excitation lights entering the excitation light combining mechanism sequentially pass through the second reflector group and the first reflector group, are output through the same light output path and enter the Raman excitation acquisition unit;

the stimulated luminescence separation mechanism comprises a first separation mirror group, wherein the first separation mirror group is at least used for reflecting stimulated luminescence to enter the detection mode switching mechanism, the first separation mirror group comprises a first separation mirror, a through hole is formed in the center of the first separation mirror, a reflection area is arranged around the through hole, the through hole is at least used for allowing the stimulated luminescence to pass through, and the reflection area is at least used for reflecting the stimulated luminescence to the detection mode switching mechanism.

2. The Raman spectrum testing system according to claim 1, wherein the plurality of excitation light sources are at least used for generating any one or more of deep ultraviolet band excitation light, visible band excitation light and near infrared band excitation light;

and/or the excitation light is a narrow linewidth laser suitable for raman excitation;

And/or the wavelength of the excitation light is 177-1024nm.

3. The raman spectrum testing system according to claim 2 wherein said lens switching mechanism comprises a mechanical translation mechanism in driving engagement with said first mirror group.

4. The Raman spectrum testing system according to claim 1, wherein the Raman excitation acquisition unit further comprises an excitation light intensity adjusting mechanism for adjusting the excitation light input to the Raman excitation acquisition unit to a set intensity and then outputting the excitation light to the excitation light focusing mechanism;

And/or the excitation light intensity adjusting mechanism comprises a neutral attenuation sheet wheel set, wherein the neutral attenuation sheet wheel set comprises at least one rotating wheel and a plurality of neutral attenuation sheets arranged on the rotating wheel;

And/or the transmittance of a plurality of the neutral attenuation sheets is at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, respectively, so that the light intensity is changed within a range of 10-100%;

And/or the neutral attenuation sheet wheel set comprises two rotating wheels, wherein one rotating wheel is provided with neutral attenuation sheets with transmittance of at least 1%, 2%, 5% and 10% respectively, the other rotating wheel is provided with neutral attenuation sheets with transmittance of at least 1%, 10%, 20% and 50% respectively, and the light intensity is changed within a range of 0.01-100% by the combination of the neutral attenuation sheets on the two rotating wheels;

And/or the rotating wheel is provided with a driving mechanism for driving the rotating wheel to rotate;

and/or, the raman excitation acquisition unit further comprises a confocal assembly, the confocal assembly comprises a first lens and a second lens which are matched with each other, a pinhole is arranged between the first lens and the second lens, the pinhole is positioned at a common focus of the first lens and the second lens, the first lens is at least used for focusing the excitation light input into the raman excitation acquisition unit to the pinhole, and the second lens is at least used for collimating the excitation light transmitted through the pinhole into parallel light and transmitting the parallel light to the excitation light intensity adjusting mechanism.

5. The Raman spectrum testing system according to claim 4, wherein the excitation light focusing mechanism comprises a third mirror group for reflecting at least the excitation light transmitted by the excitation light intensity adjusting mechanism to the focusing assembly, and a focusing assembly for focusing at least the received excitation light onto a sample to be tested, the sample to be tested receiving the excitation light and exciting a Raman signal to generate an excited light;

and/or, the focusing assembly comprises an objective lens;

and/or the raman excitation acquisition unit further comprises a sample containing mechanism, wherein the sample containing mechanism is used for containing a sample to be detected;

And/or the sample containing mechanism is arranged on the objective table, and the objective table can at least move in a three-dimensional space so as to realize the displacement of the sample to be detected and the focusing of laser on the surface of the sample.

6. The Raman spectrum testing system according to claim 1, wherein the first separating mirror is any one of a dichroic mirror, a long-wave pass filter, and a small mirror.

7. The Raman spectrum test system according to claim 1, wherein the Raman excitation acquisition unit further comprises an illumination light source module, the illumination light source module comprises a light source assembly, a beam splitting assembly, a beam splitter moving mechanism and an illumination detection assembly, the light source assembly is used for generating illumination light, the beam splitter moving mechanism is connected with the beam splitting assembly and at least used for driving the beam splitting assembly to switch between a third working mode and a fourth working mode, when the Raman excitation acquisition unit is in the third working mode, the beam splitting assembly is used for conveying the illumination light to the sample to be tested and generating scattered illumination light, the beam splitting assembly is used for conveying the scattered illumination light to the illumination detection assembly, the illumination detection assembly is used for receiving the scattered illumination light and achieving microscopic observation and focusing assistance of the sample to be tested, and when the Raman excitation acquisition light path is not affected, the beam splitting assembly is moved out of the excitation light path and the stimulated luminescence light path when the Raman excitation acquisition unit is in the fourth working mode;

And/or the light source assembly comprises a light source, a light homogenizing device and a collimation device, wherein the light source generates the illumination light, and the illumination light is conveyed to the light splitting assembly through the light homogenizing device and the collimation device in sequence;

And/or the beam splitting assembly comprises a first beam splitting mirror group and a second beam splitting mirror group, the beam splitting mirror moving mechanism is used for moving a second beam splitting mirror in the second beam splitting mirror group between a first position and a second position, when the beam splitting mirror is positioned at the first position, the beam splitting assembly is positioned in a third working state, the illumination light is sequentially transmitted to the sample to be detected through the first beam splitting mirror group and the second beam splitting mirror group, the scattered illumination light is sequentially transmitted to the illumination detection assembly through the second beam splitting mirror group and the first beam splitting mirror group, when the beam splitting mirror is positioned at the second position, the beam splitting mirror is positioned in a fourth working state, and the second beam splitting mirror moves out of the exciting light and the light path of the exciting light;

and/or the first spectroscope group comprises a first spectroscope lens, and the lens ratio of the first spectroscope lens to the first spectroscope lens is 10:90,20:80,30:70,40:60,50:50,60:40,70:30,80:20,90:10;

And/or, the inverse ratio of the lenses of the first beam-splitting lens is 50:50;

and/or the first light-splitting lens is any one of a light-splitting prism, a light-splitting flat sheet, a light-splitting wafer and a light-splitting ellipse;

And/or the number of the groups of groups, the inverse ratio of the second beam splitting lens to the second beam splitting lens is 10:90,20:80,30:70,40:60,50:50,60:40,70:30,80:20,90:10;

and/or, the inverse ratio of the lenses of the second beam-splitting lens is 10:90;

And/or, the second beam splitting lens is a beam splitting prism;

And/or the illumination detection assembly comprises an illumination detector, a linear polaroid and a lens group, wherein scattered illumination light is conveyed to the illumination detector through the linear polaroid and the lens group in sequence, the linear polaroid at least improves the contrast ratio of illumination imaging through rotary extinction, the lens group at least images the scattered illumination light on the illumination detector, and the illumination detector is used for microscopic observation and focusing assistance of a sample to be detected;

and/or, the lens group is an aberration-eliminating design lens group;

and/or the illumination detector is one or a combination of a camera and an eyepiece.

8. The raman spectroscopy system according to claim 1, wherein said detection mode switching mechanism comprises a fourth mirror group and a lens moving mechanism for switching a fourth mirror of said fourth mirror group between a third position in which said detection mode switching mechanism is in a first operating mode and a fourth position in which said detection mode switching mechanism is in a second operating mode;

And/or, the detection mode switching mechanism further comprises a first focusing element and a second focusing element, in the first working mode, the fourth reflecting mirror reflects the stimulated luminescence to the first focusing element, the first focusing element focuses the stimulated luminescence to be transmitted to the corresponding spectrometer, in the second working mode, the fourth reflecting mirror moves out of the optical path, and the second focusing element focuses the stimulated luminescence to be transmitted to the corresponding spectrometer;

And/or the first focusing element comprises any one of an off-axis parabolic mirror, a convex lens and a concave spherical reflector;

and/or the second focusing element comprises any one of an off-axis parabolic mirror, a convex lens and a concave spherical mirror.

9. A raman spectrum testing method, characterized in that the testing method is implemented based on a raman spectrum testing system according to any one of claims 1-8, and the method comprises:

the working mode of the detection mode switching mechanism is adjusted, so that the stimulated luminescence entering the spectrum detection unit enters the detection mechanism after passing through a selected spectrometer to realize high-sensitivity mode detection, or the stimulated luminescence entering the spectrum detection unit enters the detection mechanism after passing through a plurality of spectrometers in sequence to realize high-resolution mode or low-wave number mode detection;

The excitation light unit comprises a plurality of excitation light sources and an excitation light combining mechanism, wherein the excitation light combining mechanism comprises a first reflecting mirror group, a lens switching mechanism, a second reflecting mirror group and a lens angle adjusting mechanism, and the excitation light unit is used for combining excitation light with a plurality of different wavelengths and then transmitting the combined excitation light to the Raman excitation acquisition unit, and the Raman excitation acquisition unit specifically comprises:

the multiple excitation light sources generate excitation light with multiple different wavelengths;

The lens switching mechanism is used for respectively switching a plurality of first reflectors in the first reflector group to corresponding working positions;

The lens angle adjusting mechanism adjusts the reflection angles of a plurality of first and second reflectors in the first and second reflector groups respectively, so that a plurality of excitation lights entering the excitation beam combining mechanism sequentially pass through the second reflector group and the first reflector group and then are output through the same light output path, and enter the Raman excitation acquisition unit;

wherein, after separating the stimulated luminescence from the excitation light, the stimulated luminescence is transmitted to a spectrum detection unit, and the method specifically comprises the following steps:

enabling the excitation light to enter a spectrum detection unit through a through hole;

the stimulated luminescence enters a spectrum detection unit through a reflection area arranged around the through hole.

10. The raman spectrum testing method according to claim 9, characterized by comprising in particular:

The stimulated luminescence entering the spectrum detection unit sequentially passes through a plurality of spectrometers, wherein each spectrometer has a light splitting effect, so that a signal spectrum is cascaded and amplified by a plurality of spectrometers and then enters a detection mechanism to obtain a high-resolution spectrum, and high-resolution mode detection is realized;