Microscopic angle-resolved spectroscopy measurement system based on mirrors to achieve variable-angle excitation

Abstract

The present invention discloses a microscopic angular resolution spectroscopy measurement system that realizes variable-angle excitation based on a reflector, which belongs to the field of microscopic angular resolution spectroscopy measurement. The present invention realizes variable-angle excitation of the sample by changing the incident angle of the reflector so that the incident light beam is focused at different positions of the rear focal plane of the objective lens. The light signals of different angles emitted by the sample are transformed from real space to k space through the objective lens and two plano-convex lenses through Fourier transformation. The image of the k space of the rear focal plane of the objective lens is moved to the slit of the spectrometer. The one-time collection of light signals of different angles significantly shortens the spectrum collection time, thereby improving the efficiency of microscopic angular resolution spectroscopy measurement. The present invention realizes regional illumination and positioning of micron-level samples by adding a micro-area imaging module, and realizes light excitation of predetermined positions of micro-area samples while observing the samples in real time through a semi-transparent and semi-reflective mirror, without switching any optical elements in the light path, so as to collect the angular resolution spectrum of the micro-area samples in real time.

Description

Technical Field

[0001] The present invention relates to an angle-resolved spectrum measurement system, in particular to a microscopic angle-resolved spectrum measurement system based on a reflector to realize variable-angle excitation, and belongs to the field of microscopic angle-resolved spectrum measurement. Background Art

[0002] Studying the interaction between light and matter is of great significance to the development of optoelectronic devices such as optical detectors, emitters, and lasers. Exciton-polaritons are quasiparticles formed by strong coupling between photons and excitons. They have the dual characteristics of photons and excitons, can achieve room-temperature Bose-Einstein condensation and low-threshold polariton lasers, and are conducive to the development of various polaritonic devices. Surface plasmon polaritons, generally referring to the resonant motion of free electrons in metal nanostructures, have many special optical properties. They can localize the electromagnetic field within the subwavelength range, thereby breaking through the diffraction limit and realizing the control of the electromagnetic field at the nanoscale. At the same time, they localize the electromagnetic field energy within the wavelength range near the metal-medium interface, which greatly enhances the electromagnetic field near the interface. This is of great significance to the study of surface enhancement phenomena such as surface-enhanced Raman scattering, surface-enhanced fluorescence, and surface-enhanced infrared spectroscopy.

[0003] Since quasiparticles such as exciton polaritons and surface plasmon polaritons have dispersion characteristics, their characteristics and control methods can be studied through angle-resolved spectroscopy, so there is a demand for the research and development of angle-resolved spectroscopy systems. Variable-angle excitation plays a vital role in studying quasiparticles with dispersion characteristics. At present, some angle-resolved spectroscopy test systems need to move a pinhole (for example, the announcement number CN103884659A, named angle-resolved micro-nano spectroscopy analysis device) or a lens assembly (for example, the announcement number CN110274879A, named micro-angle-resolved spectroscopy measurement system) in the process of collecting angle-resolved spectra; and in the process of achieving variable-angle excitation, it is also necessary to move the pinhole or lens assembly, which greatly increases the instability of the system and the complexity of the mechanical structure. Summary of the Invention

[0004] The main purpose of the present invention is to provide a microscopic angularly resolved spectroscopy measurement system based on a reflector for variable-angle excitation. By changing the incident angle of the reflector, the incident light beam is focused at different positions on the rear focal plane of the objective lens, thereby irradiating the sample stage at different angles, achieving variable-angle excitation of the sample. The light signals at different angles emitted by the sample are Fourier transformed through the objective lens and two plano-convex lenses to achieve real-space to k-space conversion. The k-space image of the rear focal plane of the objective lens is transferred to the slit of the spectrometer. The simultaneous acquisition of light signals at different angles significantly shortens the spectrum acquisition time, thereby improving the efficiency of microscopic angularly resolved spectroscopy measurement. The present invention achieves regional illumination and positioning of micron-level samples by adding a micro-area imaging module. The semi-transparent and semi-reflective mirror is used to achieve light excitation at the predetermined position of the micro-area sample while observing the sample in real time. No optical components in the optical path need to be switched, so that the angularly resolved spectrum of the micro-area sample can be collected in real time. The present invention has the advantages of high efficiency, high precision, strong stability, simple operation, and compact structure for microscopic angularly resolved spectroscopy measurement.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The invention discloses a microscopic angle-resolved spectrum measurement system for realizing variable-angle excitation based on a reflector, which comprises an excitation light path and an angle-resolved collection light path.

[0007] The main function of the excitation light path is to focus the incident light beam at different positions of the rear focal plane of the objective lens by changing the incident angle of the reflector, so that the incident light beam is irradiated onto the sample stage at different angles, thereby realizing variable-angle excitation of the sample. The excitation light path includes a laser light source, a first convex lens, a pinhole, a second convex lens, a reflector, a third convex lens, an objective lens, and a three-axis sample displacement stage. The laser light emitted by the laser light source is converged onto the pinhole through the first convex lens. The pinhole filters out stray light and shapes the laser into a Gaussian-shaped laser. The laser light is then converted into a parallel light beam through the second convex lens. The pinhole is located at the focal position of the first convex lens and the second convex lens. The focal length ratio of the first convex lens to the second convex lens determines the size of the output light spot. The parallel laser light passes through the reflector, passes through the first semi-transparent and semi-reflective mirror, and is converged on the rear focal plane P1 of the objective lens by the third convex lens. It is then converted into parallel light through the objective lens and irradiated onto the three-axis sample displacement stage. By changing the incident angle of the reflector, the incident light beam is focused at different positions on the rear focal plane of the objective lens, so that the incident light beam is irradiated onto the three-axis sample translation stage at different angles, realizing variable-angle excitation of the sample.

[0008] To ensure that the laser beam maintains a constant diameter and is emitted in parallel, a first convex lens, a pinhole, and a second convex lens are preferably used to achieve spatial filtering of the laser beam, converting the emitted laser beam into parallel Gaussian light. The focal length ratio of the first and second convex lenses is 1:1, and the pinhole is located at the focal point of the first and second convex lenses. The focal length ratio of the first and second convex lenses is 1:1.

[0009] The angle-resolved collection optical path mainly functions as follows: light signals at different angles emitted by the sample are Fourier transformed through the objective lens and two plano-convex lenses to realize the conversion from real space to k-space, and the image of the k-space of the rear focal plane of the objective lens is moved to the slit of the spectrometer, so as to collect light signals at different angles at one time. The angle-resolved collection optical path includes a three-axis sample displacement stage, an objective lens, a third convex lens, a first semi-transparent and semi-reflective mirror, a fourth convex lens, a spectrometer slit, an EMCCD, and a spectrometer. Light signals at different angles emitted from the sample are converged on the rear focal plane P1 of the objective lens through the objective lens, and then the divergent light signals are converted into parallel light beams by the third convex lens, and the parallel light signals are reflected to the fourth convex lens by the first semi-transparent and semi-reflective mirror. The fourth convex lens converges the parallel light signals to the spectrometer slit, and the wavelength resolution is realized by the spectrometer, and the angle resolution is realized by the EMCCD. The reflector is located on the focal plane of the third convex lens, the objective lens and the third convex lens are co-focal, the third convex lens and the fourth convex lens are co-focal, and the spectrometer slit is located at the focal position of the fourth convex lens. The objective lens converts the angular information emitted by the sample into position information of the rear focal plane P1. The third convex lens and the fourth convex lens work together to move the k-space image of the objective lens rear focal plane P1 to the spectrometer slit, thereby achieving one-time collection of light signals at different angles, that is, achieving one-time collection of microscopic angle-resolved spectra. Because the present invention collects light signals at different positions in k-space through the spectrometer slit, it does not require a pinhole or any other components that require mechanical control and movement, thus achieving one-time collection of angle-resolved spectra, simplifying the mechanical structure of the optical path, and significantly shortening the spectrum collection time.

[0010] Preferably, the microscopic angle-resolved spectroscopy measurement system for realizing variable-angle excitation based on a reflector disclosed in the present invention includes, in addition to an excitation light path and an angle-resolved collection light path, a micro-area imaging module.

[0011] The micro-area imaging module is mainly used to achieve regional illumination and positioning of micron-level samples, and to achieve excitation of light at a predetermined position of the micro-area sample while observing the sample in real time through a semi-transparent and semi-reflective mirror, so as to collect the angular resolved spectrum of the micro-area sample in real time. The micro-area imaging module includes a second semi-transparent and semi-reflective mirror, a third semi-transparent and semi-reflective mirror, an objective lens, a three-axis sample displacement stage, an imaging CCD, and a white light source. The white light emitted by the white light source is reflected into the objective lens through the second semi-transparent and semi-reflective mirror, and is focused onto the three-axis sample displacement stage to achieve sample illumination. The white light reflected by the sample is reflected onto the imaging CCD through the third semi-transparent and semi-reflective mirror to achieve sample illumination imaging. That is, the second semi-transparent and semi-reflective mirrors are used to ensure that the excitation light beam and the collection signal do not interfere with the imaging illumination light path, so that the light at the predetermined position of the micro-area sample is excited while observing the sample in real time, and there is no need to switch any optical elements in the light path, so as to collect the angular resolved spectrum of the micro-area sample in real time.

[0012] The working method of the microscopic angle-resolved spectroscopy measurement system based on a reflector to achieve variable-angle excitation disclosed in the present invention is as follows:

[0013] In the excitation light path, the laser light emitted by the laser light source is converged onto a pinhole through a first convex lens. The pinhole filters out stray light and shapes the laser light into a Gaussian-shaped laser. The laser light then passes through a second convex lens to become a parallel beam. The pinhole is located at the focal position of the first and second convex lenses. The focal length ratio of the first and second convex lenses determines the size of the output light spot. The parallel laser light passes through a reflector, through a first semi-transparent and semi-reflective mirror, and is converged by a third convex lens on the rear focal plane P1 of the objective lens. It then passes through the objective lens and becomes parallel light, irradiating the three-axis sample translation stage. By changing the incident angle of the reflector, the incident light beam is focused at different positions on the rear focal plane of the objective lens, thereby irradiating the three-axis sample translation stage at different angles, achieving variable-angle excitation of the sample. The reflector is located on the focal plane of the third convex lens. The optical path difference between the two is the focal length f1 of the third convex lens. The third convex lens and the objective lens are confocal. The optical path difference between the third convex lens and the rear focal plane of the objective lens is the focal length f1 of the third convex lens. Since the laser light incident on the reflector is parallel light, the laser light reflected by the reflector is also parallel light. Since the reflector is located on the focal plane of the third convex lens, the parallel light starting from the focal plane will be converged to its second focal plane through the third convex lens. The third convex lens and the objective lens are confocal, and the second focal plane of the third convex lens coincides with the rear focal plane P1 of the objective lens. The point light source converged on the rear focal plane P1 of the objective lens will be converted into parallel light through the objective lens and illuminated to the three-axis sample translation stage. By changing the angle of the reflector, the parallel light reflected from the reflector will be converged to different positions of the rear focal plane P1 of the objective lens through the third convex lens. The point light sources at different positions will be converted into parallel light at different angles through the objective lens, realizing the change of the angle of the incident light.

[0014] In the angle-resolved collection optical path, light signals emitted from the sample at different angles converge on the objective lens's rear focal plane P1 through the objective lens. The divergent light signals are then converted into parallel beams by a third convex lens. The parallel light signals are then reflected by a first semi-transparent, semi-reflective mirror into a fourth convex lens. The fourth convex lens converges the parallel light signals onto the spectrometer slit, enabling wavelength resolution by the spectrometer and angle resolution by the EMCCD. The third and fourth convex lenses are cofocal, with the optical path difference between them being the sum of the focal length f1 of the third convex lens and the focal length f of the fourth convex lens. The spectrometer slit is located at the focal point of the fourth convex lens, and the optical path difference between them is the focal length f of the fourth convex lens. The incident laser is irradiated onto the sample at a certain angle. The objective lens converts the angular information emitted by the sample into the position information of the rear focal plane P1. The third convex lens and the fourth convex lens work together to move the k-space image of the rear focal plane P1 of the objective lens to the slit of the spectrometer. The k-space images at different positions on the slit correspond to the light signals at different angles emitted by the sample. Due to the internal structure of the spectrometer, the position information of the signal k-space at the light input and light output does not change, that is, the angle information does not change. The wavelength resolution is only achieved through spectroscopy. The EMCCD coupled to the light output port of the spectrometer performs angle resolution through the position of the light signal on the photosensitive chip, thereby obtaining the angular resolved spectrum of the sample. The reflector is located on the focal plane of the third convex lens, the objective lens and the third convex lens are co-focal, the third convex lens and the fourth convex lens are co-focal, and the spectrometer slit is located at the focal position of the fourth convex lens. The objective lens converts the angular information emitted by the sample into position information of the rear focal plane P1. The third convex lens and the fourth convex lens work together to move the k-space image of the objective lens rear focal plane P1 to the spectrometer slit, thereby achieving one-time collection of light signals at different angles, that is, achieving one-time collection of microscopic angle-resolved spectra. Because the present invention collects light signals at different positions in k-space through the spectrometer slit, it does not require a pinhole or any other components that require mechanical control and movement, thus achieving one-time collection of angle-resolved spectra, simplifying the mechanical structure of the optical path, and significantly shortening the spectrum collection time.

[0015] In the micro-area imaging module, white light emitted by a white light source is reflected into the objective lens through a second semi-transparent and semi-reflective mirror, and is focused onto a three-axis sample displacement stage to realize sample illumination. The white light reflected by the sample is reflected onto an imaging CCD through a third semi-transparent and semi-reflective mirror to realize sample illumination imaging. That is, the second and third semi-transparent and semi-reflective mirrors prevent the excitation light beam and the collection signal from interfering with the imaging illumination light path, and excitation of light at a predetermined position of the micro-area sample is achieved while the sample is observed in real time, without the need to switch any optical elements in the light path, so that the angular resolved spectrum of the micro-area sample can be collected in real time.

[0016] Beneficial effects:

[0017] 1. Prior art generally achieves variable-angle excitation by moving a pinhole or lens assembly. The present invention discloses a microscopic angle-resolved spectroscopy measurement system that achieves variable-angle excitation based on a reflector. By placing a reflector at the focal plane of a Fourier transform lens, the excitation light is emitted from the focal point of the Fourier transform lens. Changing the reflector angle does not change the excitation light emission position, allowing the incident light beam to focus at different positions on the rear focal plane of the objective lens. This allows the incident light beam to strike the sample stage at different angles, achieving variable-angle excitation of the sample. That is, variable-angle excitation of the sample is achieved by changing the incident angle of the reflector. This eliminates the need for a pinhole or any other components requiring mechanical control and movement, simplifies the mechanical structure of the optical path, and increases the stability of the optical path. Since variable-angle excitation of the sample only requires adjusting the reflector angle, operation is quick and easy, the angle setting range is wide, and the angle control is precise, which facilitates the miniaturization and integration of microscopic angle-resolved spectroscopy measurement systems.

[0018] 2. The present invention discloses a microscopic angular-resolved spectroscopy measurement system that uses a reflector to achieve variable-angle excitation. Light signals at different angles emitted by a sample are Fourier transformed through an objective lens and two plano-convex lenses to achieve the conversion from real space to k-space. The k-space image of the rear focal plane of the objective lens is moved to the slit of the spectrometer, enabling the one-time collection of light signals at different angles. Because the present invention utilizes the integrity of the spectrometer slit's position in k-space, light signals at different positions in k-space are collected through the spectrometer slit. Without the need for a pinhole or any other components requiring mechanical control and movement, one-time collection of angular-resolved spectra is achieved, simplifying the mechanical structure of the optical path and significantly shortening the spectrum collection time, thereby improving the efficiency of microscopic angular-resolved spectroscopy measurement.

[0019] 3. The present invention discloses a microscopic angularly resolved spectroscopy measurement system that uses a reflector to achieve variable-angle excitation. By adding a micro-area imaging module, regional illumination and positioning of micron-level samples are achieved. The principle of a semi-transparent and semi-reflective mirror is utilized to allow half of the light beam to pass through and half to reflect. This ensures that the excitation light beam and the collected signal do not interfere with the imaging illumination optical path. While observing the sample in real time, light excitation at a predetermined position of the micro-area sample is achieved without switching any optical elements in the optical path, so that the angularly resolved spectrum of the micro-area sample can be collected in real time.

[0020] 4. The microscopic angle-resolved spectroscopy measurement system based on a reflector to realize variable-angle excitation disclosed in the present invention, on the basis of achieving the above three beneficial effects, has the advantages of high efficiency, high precision, strong stability, simple operation and compact structure for microscopic angle-resolved spectroscopy measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention discloses a microscopic angle-resolved spectroscopy measurement system based on a reflector to realize variable-angle excitation.

[0022] Figure 2 This is a microscopic angle-resolved spectroscopy measurement system (divided by modules) based on a reflector to achieve variable-angle excitation.

[0023] Among them: 1—laser light source, 2—first convex lens, 3—pinhole, 4—second convex lens, 5—reflecting mirror, 6—first semi-transparent and semi-reflective mirror, 7—third convex lens, 8—second semi-transparent and semi-reflective mirror, 9—third semi-transparent and semi-reflective mirror, 10—objective lens, 11—three-axis sample translation stage, 12—imaging CCD, 13—white light source, 14—fourth convex lens, 15—spectrometer slit, 16—EMCCD, 17—spectrometer. DETAILED DESCRIPTION

[0024] In order to better illustrate the purpose and advantages of the present invention, the invention is further described below with reference to the accompanying drawings and examples.

[0025] Example 1:

[0026] like Figure 1 、 2 As shown, the present embodiment discloses a microscopic angle-resolved spectroscopy measurement system for realizing variable-angle excitation based on a reflector, comprising an excitation light path with a variable angle, a collection light path capable of realizing angle resolution, and a micro-area imaging module capable of realizing imaging and positioning of micro-area samples.

[0027] The variable-angle excitation optical path includes a laser light source 1, a first convex lens 2, a pinhole 3, a second convex lens 4, a reflector 5, a third convex lens 7, an objective lens 10, and a three-axis sample translation stage 11. The laser light emitted by the laser light source 1 is converged onto the pinhole 3 through the first convex lens 2. The pinhole 3 filters out stray light and shapes the laser light into a Gaussian shape. The laser light then passes through the second convex lens 4 to become a parallel beam. The focal length ratio of the first convex lens 2 to the second convex lens 4 is 1:1, and the pinhole 3 is located at the focal position of the first convex lens 2 and the second convex lens 4. The parallel laser light passes through the reflector 5, transmits through the first semi-transparent and semi-reflective mirror 6, and is converged by the third convex lens 7 onto the back focal plane P1 of the objective lens 10. It then passes through the objective lens 10 to become parallel light and irradiates the three-axis sample translation stage 11.

[0028] The reflector 5 is located on the focal plane of the third convex lens 7. The optical path difference between the third convex lens 7 and the objective lens 10 is equal to the focal length f1 of the third convex lens 7. The third convex lens 7 and the objective lens 10 are cofocal, and the optical path difference between the third convex lens 7 and the back focal plane of the objective lens is equal to the focal length f1 of the third convex lens 7. Since the laser light incident on the reflector 5 is parallel light, the laser light reflected by the reflector 5 is also parallel light. Since the reflector 5 is located on the focal plane of the third convex lens 7, the parallel light originating from the focal plane will be converged to its second focal plane by the third convex lens 7. Since the third convex lens 7 and the objective lens 10 are cofocal, the second focal plane of the third convex lens 7 coincides with the back focal plane P1 of the objective lens. The point light source converged on the back focal plane P1 of the objective lens will be converted into parallel light by the objective lens 10 and illuminate the three-axis sample translation stage 11. By changing the angle of the reflector 5, the parallel light reflected from the reflector 5 will be converged to different positions of the back focal plane P1 of the objective lens by the third convex lens 7. The point light sources at different positions will be converted into parallel light at different angles by the objective lens 10, thereby changing the angle of the incident light. When the angle between the reflector 5 and the incident light path is 45°, the outgoing light path is parallel to the principal optical axis of the third convex lens 7 and the objective lens 10, and the incident light is vertically incident on the three-axis sample translation stage 11. At this time, the reflector 5 is rotated. When the laser passes through the edge of the light entrance of the objective lens 10, the angle between the incident light and the three-axis sample translation stage 11 depends on the numerical aperture of the objective lens 10 used, and at this time, a limit angle of incidence is reached.

[0029] The angle-resolved collection optical path includes a three-axis sample translation stage 11, an objective lens 10, a third convex lens 7, a first semi-transparent mirror 6, a fourth convex lens 14, a spectrometer slit 15, an EMCCD 16, and a spectrometer 17. Signals emitted from the sample at different angles converge on the rear focal plane P1 of the objective lens 10 through the objective lens 10. The divergent light signals are then converted into parallel beams by the third convex lens 7. The parallel light signals are reflected by the first semi-transparent mirror 6 into the fourth convex lens 14, which converges the parallel signals onto the spectrometer slit 15. The spectrometer 17 achieves wavelength resolution, and the EMCCD 16 achieves angle resolution.

[0030] The third convex lens 7 and the fourth convex lens 14 are cofocal, with the optical path difference between them being the sum of the focal length f1 of the third convex lens 7 and the focal length f2 of the fourth convex lens 14. The spectrometer slit 15 is located at the focal point of the fourth convex lens 14, with the optical path difference between them being the focal length f2 of the fourth convex lens 14. When incident laser light strikes the sample at a certain angle, the objective lens 10 converts the angular information emitted by the sample into positional information of the back focal plane P1. The third convex lens 7 and the fourth convex lens 14 work together to shift the k-space image of the back focal plane P1 of the objective lens to the spectrometer slit 15. The k-space images at different positions on the slit correspond to light signals emitted at different angles by the sample. Due to the internal structure of the spectrometer 17, the k-space positional information of the signal at its light input and output ports remains unchanged, meaning that the angular information remains unchanged. Instead, wavelength resolution is achieved through light splitting. The EMCCD 16 coupled to the light output port of the spectrometer 17 performs angular resolution based on the position of the light signal on the photosensitive chip, thereby obtaining an angularly resolved spectrum of the sample.

[0031] The micro-area imaging module capable of imaging and positioning the micro-area sample includes a second semi-transparent mirror 8, a third semi-transparent mirror 9, an objective lens 10, a three-axis sample translation stage 11, an imaging CCD 12, and a white light source 13. The white light emitted by the white light source 13 is reflected by the second semi-transparent mirror 8 into the objective lens 10 and focused onto the three-axis sample translation stage 11 to illuminate the sample. The white light reflected by the sample is reflected by the third semi-transparent mirror 9 onto the imaging CCD 12 to illuminate and image the sample. The white light source 13 is turned on, and the distance between the three-axis sample translation stage 11 and the objective lens 10 is adjusted until a clear image of the sample can be seen in the imaging CCD 12. The other two axes of the three-axis sample translation stage 11 are then moved to position the sample for laser irradiation. This excitation is then directed to a specific position of the micro-area sample in order to collect an angularly resolved spectrum of the micro-area sample. The present invention can change the excitation angle by rotating a specific reflector, enabling quick and easy variable-angle excitation. The micro-area imaging module can image and locate micron-scale samples, satisfying the need for excitation at specific locations within micro-areas. The present invention can be used for angle-resolved spectroscopy of quasiparticles with dispersion characteristics and can achieve quantitative angle-resolved spectroscopy with variable-angle excitation.

[0032] The above specific description further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A microscopic angle-resolved spectroscopy measurement system based on a reflector for variable-angle excitation, characterized by: Including excitation light path and angle-resolved collection light path; The main function of the excitation light path is to focus the incident light beam at different positions of the rear focal plane of the objective lens by changing the incident angle of the reflector, so that the incident light beam is irradiated onto the sample stage at different angles, thereby realizing variable-angle excitation of the sample; the excitation light path comprises a laser light source (1), a first convex lens (2), a pinhole (3), a second convex lens (4), a reflector (5), a third convex lens (7), an objective lens (10), and a three-axis sample displacement stage (11); the laser light emitted by the laser light source (1) is converged onto the pinhole (3) through the first convex lens (2), and the pinhole (3) filters out stray light and shapes the laser light into a Gaussian-shaped laser light, which is then transformed into a flat laser light through the second convex lens (4). The pinhole (3) is located at the focal position of the first convex lens (2) and the second convex lens (4), and the focal length ratio of the first convex lens (2) to the second convex lens (4) determines the size of the output light spot; the parallel laser passes through the reflector (5), through the first semi-transparent and semi-reflective mirror (6), and is converged by the third convex lens (7) on the back focal plane P1 of the objective lens (10), and then becomes parallel light through the objective lens (10) and irradiates the three-axis sample displacement stage (11); by changing the incident angle of the reflector (5), the incident light beam is focused at different positions of the back focal plane of the objective lens (10), so that the incident light beam is irradiated on the three-axis sample displacement stage (11) at different angles, thereby realizing variable angle excitation of the sample; The angle-resolved collection optical path mainly functions as follows: light signals of different angles emitted by the sample are transformed from real space to k space through the objective lens and two plano-convex lenses by Fourier transformation, and the image of the k space of the rear focal plane of the objective lens is moved to the slit of the spectrometer, so as to collect light signals of different angles at one time; the angle-resolved collection optical path comprises a three-axis sample displacement stage (11), an objective lens (10), a third convex lens (7), a first semi-transparent and semi-reflective mirror (6), a fourth convex lens (14), a spectrometer slit (15), an EMCCD (16), and a spectrometer (17); light signals of different angles emitted from the sample are converged on the rear focal plane P1 of the objective lens (10) through the objective lens (10), and the divergent light signals are converted into parallel light beams by the third convex lens (7), and the parallel light signals are reflected to the fourth convex lens (14) by the first semi-transparent and semi-reflective mirror (6), and the fourth convex lens (14) converges the parallel light signals to the spectrometer slit (15), and the spectrometer (17) The wavelength resolution is achieved, and the angle resolution is achieved by the EMCCD (16); the reflector (5) is located on the focal plane of the third convex lens (7), the objective lens (10) and the third convex lens (7) are co-focused, the third convex lens (7) and the fourth convex lens (14) are co-focused, and the spectrometer slit (15) is located at the focal position of the fourth convex lens (14); the objective lens (10) converts the angle information emitted by the sample into the position information of the rear focal plane P1; the third convex lens (7) and the fourth convex lens (14) work together to move the k-space image of the rear focal plane P1 of the objective lens to the spectrometer slit (15), thereby achieving one-time collection of light signals at different angles, that is, achieving one-time collection of microscopic angle-resolved spectra; because the present invention collects light signals at different positions in the k-space through the spectrometer slit, no pinhole or any other components that require mechanical control and movement are required, so that one-time collection of angle-resolved spectra can be achieved, the mechanical structure of the optical path is simplified, and the spectrum collection time is significantly shortened.

2. The microscopic angle-resolved spectroscopy measurement system based on a reflector for achieving variable-angle excitation according to claim 1, characterized in that: In addition to the excitation light path and the angle-resolved collection light path, it also includes a micro-area imaging module; The micro-area imaging module mainly functions to realize regional illumination and positioning of micron-level samples, and realizes light excitation of predetermined positions of micro-area samples while observing the samples in real time through a semi-transparent and semi-reflective mirror, so as to collect the angular resolution spectrum of the micro-area samples in real time; the micro-area imaging module comprises a second semi-transparent and semi-reflective mirror (8), a third semi-transparent and semi-reflective mirror (9), an objective lens (10), a three-axis sample displacement stage (11), an imaging CCD (12), and a white light source (13); the white light emitted by the white light source (13) is reflected to the objective lens through the second semi-transparent and semi-reflective mirror (8) (10), the sample is focused on the three-axis sample displacement stage (11) to realize sample illumination, and the white light reflected by the sample is reflected to the imaging CCD (12) through the third semi-transparent and semi-reflective mirror (9) to realize sample illumination imaging, that is, the excitation light beam and the collection signal are not interfered with the imaging illumination light path through the second semi-transparent and semi-reflective mirror (8) and the third semi-transparent and semi-reflective mirror (9), and the light excitation of the predetermined position of the micro-area sample is realized while the sample is observed in real time, and there is no need to switch any optical element in the light path, so as to collect the angular resolved spectrum of the micro-area sample in real time.

3. The microscopic angle-resolved spectroscopy measurement system based on a reflector for achieving variable-angle excitation according to claim 1 or 2, characterized in that: In order to ensure that the diameter of the laser beam remains unchanged and is emitted in parallel, a first convex lens (2), a pinhole (3), and a second convex lens (4) are used to realize spatial filtering of the laser so that the emitted laser light becomes parallel Gaussian light; the focal length ratio of the first convex lens (2) to the second convex lens (4) is 1:1, and the pinhole (3) is located at the focal position of the first convex lens (2) and the second convex lens (4); the focal length ratio of the first convex lens (2) to the second convex lens (4) is 1:

1.

4. The microscopic angle-resolved spectroscopy measurement system based on a reflector for variable-angle excitation according to claim 3, characterized in that: In the excitation light path, the laser light emitted by the laser light source (1) is converged onto the pinhole (3) through the first convex lens (2). The pinhole (3) filters out the stray light and shapes the laser light into a Gaussian-shaped laser light. The laser light then passes through the second convex lens (4) to become a parallel light beam. The pinhole (3) is located at the focal position of the first convex lens (2) and the second convex lens (4). The focal length ratio of the first convex lens (2) to the second convex lens (4) determines the size of the output light spot. The parallel laser light passes through the reflector (5) and the first semi-transparent semi-transparent lens (4). The reflector (6) is converged by the third convex lens (7) onto the rear focal plane P1 of the objective lens (10), and then converted into parallel light by the objective lens (10) and irradiated onto the three-axis sample displacement stage (11); by changing the incident angle of the reflector (5), the incident light beam is focused at different positions of the rear focal plane of the objective lens (10), so that the incident light beam is irradiated onto the three-axis sample displacement stage (11) at different angles, thereby realizing variable angle excitation of the sample; the reflector (5) is located on the focal plane of the third convex lens (7), and the optical path difference between the two is The focal length of the three convex lenses (7) is f1, the third convex lens (7) and the objective lens (10) are co-focused, and the optical path difference between the third convex lens (7) and the rear focal plane of the objective lens is the focal length f1 of the third convex lens (7); since the laser light incident on the reflector (5) is parallel light, the laser light reflected by the reflector (5) is also parallel light; since the reflector (5) is located on the focal plane of the third convex lens (7), the parallel light starting from the focal plane will pass through the third convex lens (7) and converge onto its second focal plane, and the third convex lens (7) and the objective lens are co-focused. The mirror (10) is confocal, the second focal plane of the third convex lens (7) coincides with the rear focal plane P1 of the objective lens, and the point light source converged on the rear focal plane P1 of the objective lens is transformed into parallel light through the objective lens (10) and irradiated onto the three-axis sample displacement stage (11); by changing the angle of the reflector (5), the parallel light reflected from the reflector (5) is converged to different positions of the rear focal plane P1 of the objective lens through the third convex lens (7), and the point light sources at different positions are transformed into parallel light of different angles through the objective lens (10), thereby realizing the change of the angle of the incident light; In the angle-resolved collection optical path, light signals at different angles emitted from the sample are converged on the rear focal plane P1 of the objective lens (10) through the objective lens (10), and then the divergent light signals are converted into parallel light beams by the third convex lens (7), and the parallel light signals are reflected to the fourth convex lens (14) through the first semi-transparent and semi-reflective mirror (6). The fourth convex lens (14) converges the parallel light signals onto the spectrometer slit (15), and the wavelength resolution is achieved by the spectrometer (17), and the angle resolution is achieved by the EMCCD (16); the third convex lens (7) and the first semi-transparent and semi-reflective mirror (6) are connected to each other. The four convex lenses (14) are confocal, and the optical path difference between them is the sum of the focal length f1 of the third convex lens (7) and the focal length f2 of the fourth convex lens (14); the spectrometer slit (15) is located at the focal position of the fourth convex lens (14), and the optical path difference between them is the focal length f2 of the fourth convex lens (14); the incident laser is irradiated onto the sample at a certain angle, and the objective lens (10) converts the angle information emitted by the sample into the position information of the rear focal plane P1, and the third convex lens (7) and the fourth convex lens (14) work together to move the k-space image of the rear focal plane P1 of the objective lens to At the slit (15) of the spectrometer, the k-space imaging at different positions on the slit corresponds to the light signals at different angles emitted by the sample. Due to the internal structure of the spectrometer (17), the position information of the signal k-space at the light inlet and the light outlet does not change, that is, the angle information does not change. The wavelength is only resolved by splitting the light. The EMCCD (16) coupled to the light outlet of the spectrometer (17) performs angle resolution based on the position of the light signal on the photosensitive chip, thereby obtaining the angular resolution spectrum of the sample. The reflector (5) is located on the focal plane of the third convex lens (7). , the objective lens (10) and the third convex lens (7) are co-focused, the third convex lens (7) and the fourth convex lens (14) are co-focused, the spectrometer slit (15) is located at the focal position of the fourth convex lens (14), the objective lens (10) converts the angle information emitted by the sample into the position information of the rear focal plane P1, the third convex lens (7) and the fourth convex lens (14) work together to move the k-space image of the rear focal plane P1 of the objective lens to the spectrometer slit (15), thereby realizing the one-time collection of light signals at different angles, that is, realizing the one-time collection of microscopic angle-resolved spectra; In the micro-area imaging module, white light emitted by a white light source (13) is reflected by a second semi-transparent and semi-reflective mirror (8) into an objective lens (10) and focused onto a three-axis sample displacement stage (11) to realize sample illumination. The white light reflected by the sample is reflected by a third semi-transparent and semi-reflective mirror (9) onto an imaging CCD (12) to realize sample illumination imaging. That is, the second semi-transparent and semi-reflective mirror (8) and the third semi-transparent and semi-reflective mirror (9) ensure that the excitation light beam and the collection signal do not interfere with the imaging illumination light path, and the excitation of light at a predetermined position of the micro-area sample is realized while the sample is observed in real time, and there is no need to switch any optical element in the light path, so that the angular resolved spectrum of the micro-area sample is collected in real time.

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