Photocurrent microscopic device with light modulation and real-time monitoring functions and modulation method

Abstract

The invention discloses a light current microscopic device with light modulation and real-time monitoring functions and a modulation method. The device comprises a bottom plate, a microscopic system support, a sample table, an objective lens, a microscopic imaging layer, a wide-field light excitation layer and a point focusing light excitation layer. Wherein the microscopic imaging layer collimates, filters, reflects and focuses broadband light to a rear focal plane of the objective lens to realize Kohler illumination, and sample light returned by the objective lens is reflected and imaged to the camera; the wide-field light excitation layer collimates the wide-field light, adjusts the power, polarization direction and light spot shape, and reflects and focuses the wide-field light to the rear focal plane of the objective lens to realize wide-field light excitation; after the point focusing light excitation layer collimates and reflects laser and adjusts power, the polarization direction and the spot size are adjusted, and the laser is focused to a sample table through an objective lens after being reflected for multiple times to achieve point focusing light excitation. The device can modulate the laser wavelength, power and the like, monitors the optical power in real time, meets the excitation light modulation requirement, is compatible with more tests and reduces the operation complexity.

Description

Technical Field

[0001] This invention belongs to the field of microscopic photocurrent detection technology, and more specifically, relates to a photocurrent microscopic device and modulation method with optical modulation and real-time monitoring functions. Background Technology

[0002] Micro-area photocurrent detection technology is a technique for high-precision measurement of the photocurrent distribution of materials or devices at the micro- and nanoscale using photocurrent microscopy devices. It offers advantages such as high spatial resolution and the ability to reflect local photoelectric properties. Its main application areas cover semiconductor materials and device development, optoelectronic device characterization, new energy materials, nanotechnology and quantum materials, biomedicine, and photocatalysis. The testing environment of the photocurrent microscopy device needs to be precisely controlled according to specific research objectives (such as material type, device structure, signal intensity, etc.), involving multiple factors such as optical conditions, electrical conditions, environmental parameters, and system configuration. During photocurrent detection, adjustments need to be made to the wavelength, intensity, spot shape, polarization state, and modulation method of the light to optimize the detection effect and adapt to different samples and research objectives.

[0003] Currently, the modification of photocurrent microscopy devices is developing towards higher performance, more functions, and better adaptability to complex samples and environments to meet the research needs of the ever-evolving fields of materials science and optoelectronics. However, existing photocurrent microscopy systems are mainly based on the modification of commercial microscopes, and while compromises are made in the design and modification, they are often difficult to be compatible in terms of multifunctionality and ease of use.

[0004] Therefore, there is an urgent need to develop a highly efficient, multifunctional, fully automated high-throughput microphotocurrent device to meet the requirements of photocurrent equipment for excitation light modulation, to be compatible with more testing needs, and to reduce the complexity of user measurement operations. Summary of the Invention

[0005] To address the problems of existing photocurrent microscopy devices, such as the difficulty in reconciling multifunctionality and ease of use, and their inability to meet current research needs, this invention provides a photocurrent microscopy device and modulation method with optical modulation and real-time monitoring functions to solve these problems.

[0006] To achieve the above objectives, this invention provides a photocurrent microscopy device with optical modulation and real-time monitoring functions, comprising a base plate on which a microscopy system support, a sample stage, and an objective lens are respectively mounted; the objective lens observes the sample on the sample stage; a microscopic imaging layer disposed on the microscopy system support is inserted into the observation optical path of the objective lens, a halogen lamp illuminates the sample via a Kohler illumination optical path, a camera images and locates the target area, records the coordinates, and then exits the imaging optical path; a wide-field light excitation layer disposed on the microscopic imaging layer is inserted into the observation optical path, an LED light source is introduced, collimated, power adjusted, polarization controlled, and light spot modulated, and projected onto the sample; an optical power meter monitors in real time and collects the light. After collecting data, the imaging optical path is exited; the point-focusing optical excitation layer located in the wide-field optical excitation layer introduces a laser source by entering the observation optical path, and focuses it onto the sample micro-area through collimation, power adjustment, polarization control, and spot size modulation; the optical power meter monitors in real time, collects data, and then exits the optical path; the microscopic imaging layer, wide-field optical excitation layer, and point-focusing optical excitation layer each achieve independent operation through an independent optical path switching mechanism, while relying on functional complementarity to achieve cooperative operation. The microscopic imaging layer first images and locates the sample, and after determining the target area, it switches to the wide-field optical excitation layer or the point-focusing optical excitation layer to perform optical excitation on the located area and detect the photocurrent, and repeats the imaging to confirm.

[0007] Furthermore, the microscopic imaging layer includes a first linear motor, a first beam splitter, a tube mirror, a camera, a first reflecting mirror, a first achromatic lens, a filter, a second achromatic lens, and a halogen lamp.

[0008] Furthermore, the broadband light emitted by the halogen lamp is collimated by the second achromatic lens, filtered by the filter, reflected by the first mirror, and focused by the first achromatic lens onto the back focal plane of the objective lens. The sample light returned by the objective lens is reflected by the first beam splitter to the tube lens, and finally imaged on the camera.

[0009] Furthermore, the wide-field light excitation layer includes a wide-field light source module, a first power adjustment module, a first polarization adjustment module, and a first microscopic projection module; the wide-field light source module includes a first fiber optic adapter, a fiber optic beam guide, a second fiber optic adapter, and a single-wavelength LED. The single-wavelength LED is connected to one end of the fiber optic beam guide through the second fiber optic adapter, and the other end of the fiber optic beam guide introduces light into the wide-field light excitation layer through the first fiber optic adapter; the first power adjustment module includes a first rotary motor, a first filter turntable, a fourth achromatic lens, a first optical power meter, and a second beam splitter. The fourth achromatic lens collimates the light emitted by the wide-field light source module. The first optical beam splitter is configured to: 1) drive a first filter turntable to rotate to adjust the optical power; 2) transmit a portion of the light to a first optical power meter for real-time monitoring; 3) include a first half-wave plate, a first polarizer, and a second rotary motor, which drives the first half-wave plate to rotate, adjusting the polarization state of the light by changing the angle between the first half-wave plate and the first polarizer; 4) include a second linear motor, a second mirror, a third mirror, a third achromatic lens, and an aperture, which modulates the shape of the light spot, and the second linear motor moves the second mirror to achieve the entry / exit of the wide-field excitation layer optical path.

[0010] Furthermore, the wide-field light source module can switch the excitation wavelength by replacing single-wavelength LEDs of different wavelengths, using multi-color LEDs, or by bundling multiple optical fibers.

[0011] Furthermore, the shape of the light spot can be adjusted by replacing any one of the following: field aperture, motorized pinhole aperture, slit, or spatial light modulator.

[0012] Furthermore, the point-focusing light excitation layer includes a laser source module, a second power adjustment module, a second polarization adjustment module, and a second microscopic projection module; the laser source module includes a third fiber optic adapter and a fiber laser, the fiber laser introducing the laser into the point-focusing light excitation layer through the third fiber optic adapter; the second power adjustment module includes a seventh reflecting mirror, a seventh achromatic lens, a third rotary motor, a second filter turntable, a second optical power meter, and a third beam splitter, the seventh achromatic lens collimating the laser into parallel light, the third rotary motor driving the second filter turntable to rotate to adjust the optical power, and the third beam splitter transmitting part of the light to the second optical power meter for real-time measurement. The monitoring module includes a sixth reflecting mirror, a second half-wave plate, a second polarizer, and a fourth rotary motor. The fourth rotary motor drives the second half-wave plate to rotate, and adjusts the polarization state of the light by changing the angle between the second half-wave plate and the second polarizer. The second microscopic projection module includes a fourth reflecting mirror, a fifth reflecting mirror, a fifth achromatic lens, a sixth achromatic lens, a third linear motor, and a fourth linear motor. The third linear motor drives the sixth achromatic lens to move along the light propagation direction, and adjusts the spot size by changing its relative position with the fifth achromatic lens. The fourth linear motor drives the fourth reflecting mirror to move to achieve the entry / exit of the light path of the point-focused light excitation layer.

[0013] According to another aspect of the present invention, a method for photocurrent micromodulation using the device is also provided, comprising the following steps:

[0014] S100: Device initialization, place the sample and initially position it below the objective lens using the displacement stage;

[0015] S200: Microscopic imaging layer operation, enter the observation optical path, the halogen lamp illuminates the sample through the Kohler illumination optical path, the camera images and locates the target area, records the coordinates and then exits the optical path;

[0016] S300: Wide-field light excitation layer operation, enters the observation optical path, introduces an LED light source, and after collimation, power adjustment, polarization control, and spot modulation, projects it onto the sample; the first optical power meter monitors in real time, collects data, and then exits the optical path;

[0017] S400: Point-focusing light excitation layer operation, enters the observation optical path, introduces a laser source, and focuses it onto the sample micro-area through collimation, power adjustment, polarization control, and spot size modulation; the second optical power meter monitors in real time, collects data, and then exits the optical path;

[0018] S500: Collaborative operation, first locate the area through the microscopic imaging layer, then switch to the wide field light excitation layer / point focusing light excitation layer to excite and test the located area, and repeat imaging to confirm;

[0019] S600: End the operation, turn off the light source, reset the optical path, remove the sample, save the data and check the equipment status.

[0020] Furthermore, in step S300, during the operation of the wide-field light excitation layer, the light emitted by the LED light source is transmitted through the fiber optic beam guide, collimated by the fourth achromatic lens, and its power is adjusted by the first filter turntable. Part of the light is transmitted through the second beam splitter to the first optical power meter for monitoring. The remaining light is polarized by the first polarization adjustment module, and the light spot shape is modulated by the aperture. After being reflected by the third mirror, focused by the third achromatic lens, and reflected by the second mirror to the back focal plane of the objective lens, it is finally projected onto the sample surface in the form of parallel light.

[0021] Furthermore, in step S400, during the point-focusing light excitation layer operation, the laser emitted by the fiber laser is collimated by the seventh achromatic lens, reflected by the seventh mirror, and its power is adjusted by the second filter turntable. Part of the light is transmitted through the third beam splitter to the second optical power meter for monitoring, and the remaining light is reflected by the sixth mirror, its polarization state is controlled by the second polarization adjustment module, and then the spot size is adjusted by the cooperation of the sixth and fifth achromatic lenses. Finally, it is reflected by the fifth and fourth mirrors to the objective lens and focused into a point spot that is projected onto the sample micro-area.

[0022] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0023] 1. The photocurrent microscopy device of the present invention has the functions of laser wavelength / power / spot area / light polarization state modulation and real-time monitoring of light power, which meets the requirements of photocurrent equipment for excitation light modulation, is compatible with more testing needs, and reduces the complexity of user measurement operations.

[0024] 2. The photocurrent microscopy device of the present invention has flexible and efficient excitation wavelength switching; both the wide-field light excitation layer and the point-focusing light excitation layer adopt an external optical fiber access design, and with the quick replacement structure composed of optical fiber adapters, the excitation wavelength can be quickly switched by replacing different wavelengths of monochrome LEDs, multi-color LEDs, multi-strand optical fiber bundles or fiber lasers, etc., to adapt to the response testing requirements of different samples to specific wavelengths.

[0025] 3. The photocurrent microscopy device of the present invention has three independent optical paths: a microscopic imaging layer, a wide-field light excitation layer, and a point-focusing light excitation layer. The key components (beam splitter and reflector) are controlled by a linear stepper motor to achieve offset entry / exit of the optical path, ensuring that each layer does not interfere with each other when working independently, and that the excitation efficiency of the wide-field light and the point-focusing light excitation layer is always in the optimal state, thereby improving the flexibility of testing.

[0026] 4. The photocurrent microscopy device of the present invention has strong light spot modulation capability and adapts to diverse needs. The wide-field light excitation layer, through a microscopic projection system composed of a field aperture, an achromatic lens, etc., can flexibly adjust the shape and area of ​​the excitation light spot by changing the field aperture, motorized pinhole aperture, slit or spatial light modulator, etc., to meet the testing needs of large-area and specific shape areas. The point-focusing light excitation layer, through a modulation system composed of a linear stepper motor, an achromatic lens, etc., combined with the microcontroller-associated motor displacement and the measured light spot size, realizes automated and precise control of the point-focusing light spot size, adapting to the excitation needs of small-area, high-power-density micro-regions.

[0027] 5. The photocurrent microscopy device of the present invention has a high degree of automation and is easy to operate. By integrating multiple electric components such as XYZ axis electric displacement module, linear motor, and rotary motor, it realizes fully automated testing operation through software communication control, reduces the complexity of user measurement operation, and supports high-throughput testing.

[0028] 6. The photocurrent microscopy device of the present invention has high imaging quality and supports precise positioning. The microscopic imaging layer reduces chromatic aberration through filters, thereby improving imaging quality. At the same time, it ensures the confocal effect with the point-focusing light excitation layer, which can realize clear imaging of the sample surface morphology and precise positioning of the target test area, providing a reliable basis for subsequent excitation tests.

[0029] 7. The photocurrent microscopy device of the present invention provides stable and controllable excitation conditions. Both the wide-field light and the point-focused light excitation layers are connected to the optical power meter through a beam splitter. The excitation light power density under the objective lens is monitored in real time using a constant beam splitting ratio to ensure the stability of excitation light power, polarization state and other conditions, thereby improving the accuracy and repeatability of the test results. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a photocurrent microscope device with optical modulation and real-time monitoring functions in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the optical path structure of the microscopic imaging layer in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the optical path structure of the wide-field photoexcitation layer in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the light spot shape modulation of the wide-field light excitation layer in an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the light spot shape modulation of the wide-field light excitation layer in another embodiment of the present invention;

[0035] Figure 6This is a schematic diagram of the optical path structure of the point-focusing light excitation layer in an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram illustrating the modulation of the spot size excited by point-focused light in an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram illustrating the modulation of the spot size excited by point-focused light in another embodiment of the present invention;

[0038] Figure 9 This is a flowchart illustrating the photocurrent micro-modulation method with optical modulation and real-time monitoring functions in an embodiment of the present invention.

[0039] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:

[0040] 1-Base plate;

[0041] 2-Microscopic system support;

[0042] 3 sample stages;

[0043] 4-Objective lens;

[0044] 5-Microscopic imaging layer, including: 51-First linear motor, 52-First beam splitter, 53-Tube mirror, 54-Camera, 55-First reflecting mirror, 56-First achromatic lens, 57-Filter, 58-Second achromatic lens, 59-Halogen lamp;

[0045] 6-Wide-field light excitation layer, comprising: 611-Second linear motor, 612-First rotary motor, 613-First filter turntable, 621-Second reflector, 622-Third reflector, 631-Third achromatic lens, 632-Fourth achromatic lens, 64-Aperture element, 641-First field-of-view aperture, 642-Second field-of-view aperture, 651-First half-wave plate, 652-First polarizer, 653-Second rotary motor, 66-First optical power meter, 67-Second beam splitter, 681-First fiber optic adapter, 682-Fiber optic beam guide, 683-Second fiber optic adapter, 69-Single-wavelength LED;

[0046] The 7-point focusing excitation layer includes: 711-fourth reflecting mirror, 712-fifth reflecting mirror, 713-sixth reflecting mirror, 714-seventh reflecting mirror, 715-fourth linear motor, 721-fifth achromatic lens, 722-sixth achromatic lens, 723-seventh achromatic lens, 731-third linear motor, 732-third rotary motor, 733-second filter turntable, 741-second half-wave plate, 742-second polarizer, 743-fourth rotary motor, 75-second optical power meter, 76-third beam splitter, 77-third fiber optic adapter, and 78-fiber laser. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0048] like Figure 1-8 As shown, the present invention provides a photocurrent microscopy device with optical modulation and real-time monitoring functions, including a base plate 1, a microscopy system support 2, a sample stage 3, an objective lens 4, a microscopic imaging layer 5, a wide-field light excitation layer 6, and a point-focusing light excitation layer 7. The microscope system support 2 and sample stage 3 are fixedly mounted on the base plate 1. The objective lens 4 observes the sample on the sample stage 3. The microscope imaging layer 5, the wide-field light excitation layer 6, and the point-focusing light excitation layer 7 are sequentially mounted on the microscope system support 2. The microscope imaging layer 5 collimates, filters, reflects, and focuses the broadband light onto the back focal plane of the objective lens 4 to achieve Kohler illumination. The sample light returned from the objective lens 4 is reflected and imaged onto the camera 54. The wide-field light excitation layer 6 collimates, adjusts the power, polarization direction, and spot shape of the wide-field light sequentially, and then reflects and focuses it onto the back focal plane of the objective lens to achieve wide-field light excitation. The point-focusing light excitation layer 7 collimates, reflects, and adjusts the power of the laser, and then adjusts the polarization direction and spot size so that the laser is focused onto the sample stage by the objective lens after multiple reflections, thus achieving point-focusing light excitation. The photocurrent microscopy device of the present invention has the functions of laser wavelength / power / spot area / light polarization state modulation and real-time monitoring of optical power, which meets the requirements of photocurrent equipment for excitation light modulation, is compatible with more testing needs, and reduces the complexity of user measurement operations.

[0049] like Figure 1 As shown in the embodiment of the present invention, the base plate 1 provides a stable foundation for the entire device, ensuring that other functional components are installed on a horizontal and stable plane.

[0050] The bottom of the microscopic system support 2 is fixedly mounted on one end of the base plate 1, and is used to install and fix the microscopic imaging layer 5, the wide field light excitation layer 6 and the point focusing light excitation layer 7.

[0051] The sample stage 3 is fixedly mounted on the other end of the base plate 1 and is used to place the sample. Preferably, the sample stage 3 is equipped with an XYZ axis electric displacement module to realize automatic adjustment of the sample position.

[0052] The objective lens 4 is positioned above the sample stage 3 and magnifies the sample image using its own magnification. Its imaging process follows the Abbe imaging principle, achieving clear imaging of sample details through diffraction and interference processing of the object light, providing a high-quality microscopic image foundation for subsequent photocurrent detection. Preferably, the objective lens 4 is mounted on an electric objective lens module, with electric control enabling objective lens switching and positioning to meet different observation needs (such as switching from low to high magnification). This electric objective lens module provides objectives with various magnifications and optical properties, and combined with the electric control system, achieves rapid and precise objective lens switching, thereby improving the automation level and observation efficiency of microscope operation.

[0053] Furthermore, the photocurrent microscopy device of the present invention also includes, but is not limited to, an XYZ axis electric displacement module, an electric objective lens module, a switching motor, an electric aperture, a slit, a spatial light modulator, and other software communication-controlled electric module components, so as to realize fully automated testing operation of the micro-area photoelectric testing system.

[0054] like Figure 2 As shown, the microscopic imaging layer 5 collimates, filters, and focuses broadband light to precisely reach the back focal plane of the objective lens, providing uniform and suitable illumination for the sample and meeting the illumination requirements for high-quality imaging. At the same time, it reflects the reflected or transmitted light from the sample collected by the objective lens and images it onto the camera through the tube lens, thereby obtaining a microscopic image of the sample. This provides visual information such as the morphology of the sample for subsequent studies such as photocurrent detection. The microscopic imaging layer 5 includes a first linear motor 51, a first beam splitter 52, a tube lens 53, a camera 54, a first reflecting mirror 55, a first achromatic lens 56, a filter 57, a second achromatic lens 58, and a halogen lamp 59.

[0055] The halogen lamp 59 emits broadband light as a light source. The emitted light contains multiple wavelengths of color light and has a wide spectral range, which can provide rich color information and is suitable for microscopic imaging of samples to present the detailed morphology of the samples.

[0056] The second achromatic lens 58 is used to correct chromatic aberration of light (reducing imaging or optical path deviations caused by refraction differences of light of different wavelengths). Simultaneously, through collimation and focusing functions, it ensures that light propagates along the expected path in each optical path, providing fundamental optical support for improving image quality, optimizing light excitation efficiency, and modulating light spots. The second achromatic lens 58 collimates and parallelizes the broadband light emitted from the halogen lamp 59 before illuminating the filter 57.

[0057] The filter 57 filters out some of the colored light from the halogen lamp 59 light source to reduce the color difference of the microscopic imaging system, thereby improving the imaging quality; at the same time, it ensures the confocal effect of the microscopic imaging and the point-focusing light excitation layer, and ensures the matching of the imaging and excitation light paths; after the broadband light is filtered out by the filter 57, it illuminates the reflector 55.

[0058] The adjustment of the reflector 55 changes the direction of light propagation. It changes the direction of propagation of the broadband light after filtering out some colored light, so that the light can continue to be transmitted to the first achromatic lens 56 and finally focused on the back focal plane of the objective lens 4 to achieve Kohler illumination, providing a suitable light path for subsequent sample imaging.

[0059] The first achromatic lens 56 has the same function as the second achromatic lens 58. It collimates and focuses the broadband light that changes the direction of light propagation onto the back focal plane of the objective lens 4, providing uniform and suitable illumination for the sample and meeting the illumination requirements for high-quality imaging.

[0060] The first beam splitter 52 mainly plays a role in beam splitting in different optical path layers, that is, allowing some light to be transmitted and some light to be reflected, thereby realizing the beam splitting process. It receives the sample light returned by the objective lens 4, reflects some light to the tube lens 53, and finally images it to the camera 54 to complete the microscopic imaging of the sample.

[0061] The sample light reflected by the tube lens 53 is focused and imaged onto the camera 54, thus completing the microscopic imaging of the sample.

[0062] The motor shaft of the first linear motor 51 is fixedly connected to the first beam splitter 52, thereby driving the beam splitter 52 to move forward or backward in a straight line, realizing the non-offset entry / exit of the imaging optical path to the observation optical path where the objective lens 4 is located. When sample microscopic imaging is required, the first linear motor 51 drives the first beam splitter 52 into the optical path, and the sample light returned by the objective lens 4 can be reflected by the first beam splitter 52 to the tube lens 53, and finally imaged to the camera 54 to complete the imaging function. When imaging is not required and only the wide-field light excitation layer 6 or the point-focusing light excitation layer 7 is needed to work, the first linear motor 51 drives the first beam splitter 52 out of the optical path to avoid the beam splitter blocking or reflection loss of the excitation light, ensuring that the excitation light can reach the sample stage 3 with higher efficiency, thereby improving the photoexcitation efficiency, while ensuring that there is no offset during the optical path switching process and does not affect the precise coordination of each optical path layer.

[0063] When the microscopic imaging layer 5 is in operation, the first linear motor 51 controls the movement of the first beam splitter 52 to achieve offset-free entry of the imaging optical path into the observation optical path of the objective lens 4, ensuring that the imaging optical path is in working condition; the halogen lamp 59 is activated, and the broadband light emitted by it is collimated by the achromatic lens 58 and converted into parallel light; the collimated light passes through the filter 57 to filter out some colored light to reduce chromatic aberration, improve imaging quality, and ensure the confocal effect with the point-focusing light excitation layer; the filtered light is reflected by the mirror 55 to change the propagation direction; the reflected light is focused by the achromatic lens 56 onto the back focal plane of the objective lens 4 to achieve Kohler illumination of the sample; the objective lens 4 receives the light reflected or transmitted from the sample (sample light), which is reflected by the beam splitter 52, transmitted through the tube lens 53, and finally imaged on the camera 54, completing the microscopic imaging process; the entire process is automatically controlled by the corresponding motors to ensure the stability and efficiency of the imaging optical path.

[0064] like Figure 3 As shown, in this embodiment of the invention, the wide-field light excitation layer 6 integrates multi-dimensional modulation (wavelength, power, polarization state, and spot shape) and real-time monitoring functions to meet diverse testing requirements in wide-field light excitation scenarios; the wide-field light excitation layer 6 includes a wide-field light source module, a first power adjustment module, a first polarization adjustment module, and a first microscopic projection module.

[0065] The wide-field light source module is used to excite the sample over a large area and a wide field of view to meet the photoelectric characteristic testing requirements of a large area in micro-area photocurrent detection. It includes a first fiber optic adapter 681, a fiber optic beam guide 682, a second fiber optic adapter 683, and a single-wavelength LED 69. The single-wavelength LED 69 is connected to one end of the fiber optic beam guide 682 via the second fiber optic adapter 683, and the other end of the fiber optic beam guide 682 is connected to the main body of the wide-field light excitation layer 6 via the first fiber optic adapter 681. By changing the LED 69 with different excitation wavelengths, rapid switching of the wide-field light excitation wavelength can be achieved. Furthermore, rapid switching of the excitation wavelength can be achieved by using multiple monochromatic LEDs, multi-color LEDs, or multiple fiber bundles.

[0066] When using multiple monochromatic LEDs, each monochromatic LED corresponds to a specific wavelength of monochromatic light. These LEDs are connected to the fiber optic guide beam of the wide-field excitation layer via fiber optic adapters. When it is necessary to switch the excitation wavelength, simply replace the monochromatic LED with one of different wavelengths using the fiber optic adapters, and the new wavelength light will be introduced into the device via the fiber optic guide beam, completing the wavelength switching. This method relies on the wavelength specificity of the monochromatic LEDs and achieves adjustment by physically replacing the light source.

[0067] When using multi-color LEDs, a multi-color LED capable of emitting light of multiple wavelengths is used as the light source, which is connected to the device via an optical fiber beam guide. The multi-color LED can output light of different wavelengths through circuit control (such as switching different light-emitting chips), eliminating the need for physical replacement of the light source. The excitation wavelength can be quickly switched simply by adjusting the electrical signal, simplifying the operation process.

[0068] When using a multi-fiber bundle method, multiple fibers transmitting different wavelengths of light are combined into a single fiber optic beam, with each fiber corresponding to a specific wavelength light source (such as different monochromatic LEDs or lasers). By controlling the light source switches of the different fibers, the target wavelength light output from the bundled fiber can be selected, thereby achieving rapid switching of the excitation wavelength. This method improves switching efficiency by replacing light source replacement with optical path selection.

[0069] The first power adjustment module adjusts the wide field light power emitted by the wide field light source module to meet the stability of the excitation conditions. It includes a first rotary motor 612, a first filter turntable 613, a fourth achromatic lens 632, a first optical power meter 66, and a second beam splitter 67.

[0070] The fourth achromatic lens 632 collimates the beam emitted by the wide-field light source module into parallel light, providing a basis for subsequent uniform modulation.

[0071] The first filter turntable 613 has multiple sets of light-transmitting holes arranged circumferentially. Different types of optical attenuators are installed within these holes. By rotating the first filter turntable 613, the target attenuator is switched into the optical path, achieving a constant ratio attenuation of optical power to the aligned parallel light. Furthermore, the center of the first filter turntable 613 is fixedly connected to the shaft of a first rotary motor 612. The first rotary motor 612 drives the first filter turntable 613 to rotate, switching the target attenuator into the optical path, achieving a constant ratio attenuation of optical power, and precisely adjusting the light intensity.

[0072] The second beam splitter 67 splits the attenuated light, and part of the attenuated light is transmitted to the optical power meter 66 for detection. By using the constant splitting ratio of the transmitted light and the reflected light, the excitation light power density under the objective lens 4 is calculated in real time to ensure stable excitation conditions. The remaining attenuated light is reflected and received by the first polarization adjustment module for polarization adjustment to adjust the linear polarization state of the excitation light.

[0073] The first polarization adjustment module is used to adjust the linear polarization state of the excitation light. It includes a first half-wave plate 651, a first polarizer 652, and a second rotary motor 653, all of which are perpendicular to the light propagation direction. The side of the first half-wave plate 651 is fixedly connected to the motor shaft of the second rotary motor 653. By changing the angle θ between the first half-wave plate 651 and the first polarizer 652 through the second rotary motor 653, the polarization direction of the outgoing light passing through the half-wave plate is rotated by 2θ relative to the calibration direction of the first polarizer 652, thereby realizing the control of the polarization direction of the point-focused excitation light.

[0074] The first microscopic projection module is used to modulate the shape of the excitation spot, and includes a second linear motor 611, a second reflector 621, a third reflector 622, a third achromatic lens 631, and an aperture 64.

[0075] The second linear motor 611 is fixedly connected to the second reflector 621, thereby driving the second reflector 621 forward or backward along a straight line. This achieves a non-offset entry / exit observation optical path for the wide-field excitation layer: when wide-field excitation is required, the linear stepper motor drives the reflector 621 into the optical path, allowing the wide-field light to propagate along a preset path; when switching to the point-focusing excitation layer or the microscopic imaging layer, the reflector 621 exits the optical path to avoid interference with other optical paths. This design ensures that the wide-field excitation layer works independently of the other two optical paths, without affecting each other, thus ensuring that the excitation efficiency of each layer is at its optimal state.

[0076] The third reflector 622 guides the light rays after polarization adjustment and light spot modulation (field stop 64) to propagate to the third achromatic lens 631 in the designed direction. Its steering function ensures that the light path is transmitted efficiently in a limited space along a preset path.

[0077] The third achromatic lens 631 focuses and collimates the wide-field light after modulating the light spot shape to the third reflecting mirror 622.

[0078] like Figure 3-4 As shown, the aperture 64 is used to adjust the shape and range of the excitation spot. It includes a first field-of-view aperture 641 and a second field-of-view aperture 642, which have different aperture shapes. By replacing the first field-of-view aperture 641 with the second field-of-view aperture 642, the projection path of the light will change accordingly, which will eventually lead to a corresponding change in the illumination position projected onto the surface of the sample stage 3 below the objective lens 4. By replacing the field-of-view apertures of different specifications, the photocurrent excitation area can be directionally adjusted, thereby precisely controlling the specific area on the sample that is excited, and meeting the diverse needs for the excitation position under different testing scenarios.

[0079] Preferably, in this embodiment of the invention, the aperture element 64 includes, but is not limited to, being placed at the field aperture position by means of an electric pinhole aperture, a slit, a spatial light modulator, etc., to achieve special adjustment of the photocurrent excitation region.

[0080] When the first microscopic projection module is in operation, the wide-field light after polarization adjustment is incident on the aperture 64. After the wide-field light is modulated by the aperture 64, it is reflected by the third mirror 622 to the third achromatic lens 631. After being focused, it is reflected by the second mirror 621 (which has now entered the optical path) to the back focal plane of the objective lens 4, and finally projected onto the sample stage surface in the form of parallel light.

[0081] In this embodiment of the invention, when the wide-field excitation layer 6 is operating, the monochromatic light emitted by the single-wavelength LED 69 is collimated into parallel light by the fourth achromatic lens 632. The parallel light is incident on the first filter turntable 613613 for constant ratio attenuation. The attenuated light is incident on the second beam splitter 67, and part of the light is transmitted to the optical power meter 66 at a constant splitting ratio. The excitation light power density under the objective lens 4 is monitored in real time by converting the ratio of transmitted light to reflected light. The remaining attenuated light is reflected and then passes sequentially through the first polarizer 652 (which determines the basic polarization direction) and the first half-wave plate 6. 51. Adjust the angle θ between the half-wave plate and the polarizer to rotate the polarization direction of the light by 2θ relative to the calibration direction, thus completing the linear polarization state modulation; after the polarized light passes through the aperture 64 to modulate the shape of the light spot, the initial shape of the excitation region is determined; the modulated light is reflected by the mirror 622, and then reflected by the third mirror 622 to the third achromatic lens 631. After being focused, it is reflected by the second mirror 621 (which has now entered the observation optical path of the objective lens 4) to the back focal plane of the objective lens 4. The light is then projected onto the surface of the sample stage 3 in the form of parallel light through the objective lens 4, thus completing the wide-field light excitation of the sample.

[0082] like Figure 6 As shown, in this embodiment of the invention, the point-focusing light excitation layer 7 focuses a laser of corresponding wavelength and power into a small-sized light spot and projects it onto the sample stage surface, thereby achieving precise excitation of a small area of ​​the sample. This meets the requirements for testing the photoelectric properties of local and small-scale areas in micro-area photocurrent detection and is suitable for scenarios requiring high light power density excitation. The point-focusing light excitation layer 7 includes a laser source module, a second power adjustment module, a second polarization adjustment module, and a second microscopic projection module.

[0083] The laser source module includes a third fiber optic adapter 77 and a fiber laser 78. The fiber optic output port of the fiber laser 78 is fixed to the third fiber optic adapter 77, and the emitted laser light is introduced into the optical path of the point-focusing excitation layer 7 through the third fiber optic adapter 77. By providing the third fiber optic adapter 77, fiber lasers of different wavelengths can be quickly replaced, and the wavelength of the point-focusing excitation light can be flexibly adjusted to meet the response testing requirements of different samples to specific wavelengths.

[0084] The second power adjustment module is used to precisely control the intensity of the excitation light. It includes a seventh reflector 714, a seventh achromatic lens 723, a third rotary motor 732, a second filter turntable 733, a second optical power meter 75, and a third beam splitter 76. Different types of optical attenuators are arranged circumferentially on the second filter turntable 733. The motor shaft of the first rotary motor 612 is fixedly connected to the center of the second filter turntable 733.

[0085] The laser beam of the corresponding wavelength is collimated into parallel light by the seventh achromatic lens 723; the parallel light is then reflected by the seventh reflecting mirror 714, changing its propagation direction; the reflected light is incident on the second filter turntable 733, which is driven to rotate by the third rotary motor 732, switching the target attenuator into the optical path to achieve a constant ratio attenuation of optical power; the attenuated light reaches the third beam splitter 76, part of which is transmitted to the second optical power meter 75 at a constant splitting ratio. By converting the ratio of transmitted light to reflected light, the excitation light power density under the objective lens 4 can be monitored in real time; the other part of the light is reflected by the third beam splitter 76 and continues to propagate along the subsequent optical path.

[0086] The second polarization adjustment module is used to adjust the linear polarization state of the excitation light, and includes a sixth reflecting mirror 713, a second half-wave plate 741, a second polarizer 742, and a fourth rotary motor 743. The side of the second half-wave plate 741 is fixedly connected to the motor shaft of the fourth rotary motor 743. The fourth rotary motor 743 changes the angle θ between the second half-wave plate 741 and the second polarizer 742. After the remaining attenuated light is reflected by the sixth reflecting mirror 713, it passes sequentially through the second polarizer 742 (which determines the basic polarization direction) and the second half-wave plate 741. By adjusting the angle θ between the half-wave plate and the polarizer, the polarization direction of the light is rotated by 2θ relative to the calibration direction, thus completing the linear polarization state adjustment.

[0087] The second microscopic projection module is used to modulate the shape of the excitation spot, and includes a fourth reflector 711, a fifth reflector 712, a fifth achromatic lens 721, a sixth achromatic lens 722, and a third linear motor 731.

[0088] The excitation light, after completing the linear polarization state modulation, is focused by the sixth achromatic lens 722 at its initial position, and then re-collimated into parallel light by the fifth achromatic lens 721. The parallel light is reflected by the fifth mirror 712 and the fourth mirror 711 in sequence and enters the objective lens 4, and finally converges onto the sample stage 3 to form a light spot of the initial size.

[0089] like Figure 7-8As shown, when adjusting the light spot, when the third linear motor 731 drives the sixth achromatic lens 722 to move along the light propagation direction, its relative position with the fifth achromatic lens 721 changes, causing the light emitted through the fifth achromatic lens 721 to no longer be strictly parallel (exhibiting certain diverging or converging characteristics); this non-parallel light is deflected by the mirror and enters the objective lens 4, and the size of the light spot that finally converges on the sample stage 3 will increase accordingly.

[0090] Furthermore, the fourth reflecting mirror 711 is fixedly mounted on the motor shaft of the fourth linear motor 715, thereby driving the fourth reflecting mirror 711 to move forward or backward in a straight line, realizing the non-offset entry / exit of the observation optical path of the point-focusing light excitation layer 7 and the objective lens 4, ensuring that the point-focusing light excitation optical path is independently separated from the microscopic imaging layer 5 and the wide-field light excitation layer 6, providing an interference-free optical path foundation for the subsequent excitation process, and ensuring optimal excitation efficiency.

[0091] When the microscopic imaging layer 5 is in operation, the laser emitted by the fiber laser 78 is collimated into parallel light by the seventh achromatic lens 723. The collimated parallel light is reflected by the seventh reflecting mirror 714, changing its propagation direction and guiding it to the second filter turntable 733 to achieve a constant ratio attenuation of optical power. The attenuated light reaches the third beam splitter 76, and part of it is transmitted to the second optical power meter 75 at a constant splitting ratio. By converting the ratio of transmitted light to reflected light, the excitation light power density under the objective lens 4 can be monitored in real time. The remaining light reflected by the third beam splitter 76 is reflected by the sixth reflecting mirror 713 and then passes sequentially through the second polarizer 742 and the second half-wave plate 741. The second half-wave plate 741 is rotated by the fourth rotary motor 743, changing its propagation direction. By changing the angle θ between the emitted light and the second polarizer 742, the polarization direction of the emitted light is rotated by 2θ relative to the calibration direction, achieving precise control of the linear polarization state. The polarized light is then incident on the sixth achromatic lens 722. The displacement of the sixth achromatic lens 722 along the light propagation direction is precisely controlled by the third linear motor 731, changing its relative position with the fifth achromatic lens 721 and adjusting the size of the focused spot. The light, after being modulated by the spot size, is reflected sequentially by the fifth mirror 712 and the fourth mirror 711, changing its propagation direction and precisely pointing towards the objective lens 4. After entering the objective lens 4, the light is focused by the objective lens into a high-power-density spot, which is finally projected onto the surface of the sample stage 3, completing the point-focused light excitation of a small area of ​​the sample.

[0092] In this embodiment of the invention, the microscopic imaging layer 5, the wide-field light excitation layer 6, and the point-focusing light excitation layer 7 work together to achieve a more complex testing process, including:

[0093] Synergy between imaging and excitation: The microscopic imaging layer 5 first images and locates the sample. After determining the target area, it switches to the wide-field light excitation layer 6 or the point-focusing light excitation layer 7 to excite the located area and detect the photocurrent, thus realizing a coherent process of "location-excitation-detection".

[0094] The wide-field light excitation layer 6 (large-scale excitation) and the point-focused light excitation layer 7 (small-area excitation) can be used alternately. Combined with the observation of the microscopic imaging layer 5, the differences in photoelectric properties of samples under different excitation modes can be compared.

[0095] The three devices operate independently through an independent optical path switching mechanism, while also cooperating based on their complementary functions (imaging positioning and precise excitation), flexibly meeting the needs of micro-area photocurrent detection from simple to complex.

[0096] The photocurrent microscopy device of the present invention has the functions of laser wavelength / power / spot area / light polarization state modulation and real-time monitoring of optical power, which meets the requirements of photocurrent equipment for excitation light modulation, is compatible with more testing needs, and reduces the complexity of user measurement operations.

[0097] The photocurrent microscopy device of the present invention features flexible and efficient excitation wavelength switching. Both the wide-field excitation layer and the point-focusing excitation layer adopt an external optical fiber access design. With the quick-change structure composed of optical fiber adapters, the excitation wavelength can be quickly switched by replacing different wavelengths of monochrome LEDs, multi-color LEDs, multi-strand optical fiber bundles, or fiber lasers, thus adapting to the response testing requirements of different samples to specific wavelengths.

[0098] The photocurrent microscopy device of the present invention has three independent optical paths: a microscopic imaging layer, a wide-field light excitation layer, and a point-focused light excitation layer. The key components (beam splitter and reflector) are controlled by a linear stepper motor to achieve offset entry / exit of the optical path, ensuring that each layer does not interfere with each other when working independently, and that the excitation efficiency of the wide-field light and the point-focused light excitation layer is always in the optimal state, thereby improving the flexibility of testing.

[0099] The photocurrent microscopy device of this invention has strong light spot modulation capability and can adapt to diverse needs. The wide-field excitation layer, through a microscopic projection system composed of a field aperture, an achromatic lens, etc., can flexibly adjust the shape and area of ​​the excitation spot by changing the field aperture, motorized pinhole aperture, slit, or spatial light modulator, etc., to meet the testing needs of large-area and specific shape areas. The point-focusing excitation layer, through a modulation system composed of a linear stepper motor, an achromatic lens, etc., combined with a microcontroller-associated motor displacement and the measured spot size, realizes automated and precise control of the point-focusing spot size, adapting to the excitation needs of small-area, high-power-density micro-regions.

[0100] The photocurrent microscopy device of the present invention is highly automated and easy to operate. By integrating multiple electric components such as XYZ axis electric displacement module, linear motor, and rotary motor, it realizes fully automated testing operation through software communication control, reducing the complexity of user measurement operation and supporting high-throughput testing.

[0101] The photocurrent microscopy device of the present invention has high imaging quality and supports precise positioning. The microscopic imaging layer reduces chromatic aberration through filters, thereby improving imaging quality. At the same time, it ensures the confocal effect with the point-focusing light excitation layer, which can realize clear imaging of sample surface morphology and precise positioning of target test area, providing a reliable foundation for subsequent excitation tests.

[0102] The photocurrent microscopy device of the present invention provides stable and controllable excitation conditions. Both the wide-field light and the point-focused light excitation layers are used in conjunction with a beam splitter and an optical power meter. By using a constant beam splitting ratio, the excitation light power density under the objective lens is monitored in real time to ensure the stability of conditions such as excitation light power and polarization state, thereby improving the accuracy and repeatability of test results.

[0103] The present invention also provides a photocurrent micro-modulation method with optical modulation and real-time monitoring functions, comprising the following steps:

[0104] S100: Device initialization, place the sample and initially position it below the objective lens using the displacement stage;

[0105] S200: Microscopic imaging layer operation, enter the observation optical path, the halogen lamp illuminates the sample through the Kohler illumination optical path, the camera images and locates the target area, records the coordinates and then exits the optical path;

[0106] S300: Wide-field light excitation layer operation, enters the observation optical path, introduces an LED light source, and after collimation, power adjustment, polarization control, and spot modulation, projects it onto the sample; the optical power meter monitors in real time, collects data, and then exits the optical path;

[0107] S400: Point-focusing light excitation layer operation, enters the observation optical path, introduces a laser source, and focuses it onto the sample micro-area through collimation, power adjustment, polarization control, and spot size modulation; the optical power meter monitors in real time, collects data, and then exits the optical path;

[0108] S500: Collaborative operation, first locate the area through the microscopic imaging layer, then switch to the wide field light excitation layer / point focusing light excitation layer to excite and test the located area, and repeat imaging to confirm;

[0109] S600: End the operation, turn off the light source, reset the optical path, remove the sample, save the data and check the equipment status.

[0110] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A photocurrent microscopy device with light modulation and real-time monitoring functions, characterized in that, The utility model relates to a microscope system, including: a base plate (1) having a microscope system support (2), a sample stage (3) and an objective lens (4) respectively disposed thereon, wherein the objective lens (4) is used for observing a sample on the sample stage (3); a microscopic imaging layer (5) disposed on the microscope system support (2), wherein the microscopic imaging layer (5) is used for cutting into an observation light path of the objective lens (4), illuminating the sample by a halogen lamp (59) through a Kohler illumination light path, positioning a target region by a camera imaging, recording coordinates and then exiting the imaging light path; a wide-field light excitation layer (6) disposed on the microscopic imaging layer (5), wherein the wide-field light excitation layer (6) is used for cutting into the observation light path, introducing an LED light source, collimating, power adjusting, polarization regulating and spot modulating, and projecting the light to the sample; a light power meter is used for real-time monitoring and collecting data, and then exiting the imaging light path; a point focusing light excitation layer (7) disposed on the wide-field light excitation layer (6), wherein the point focusing light excitation layer (7) is used for cutting into the observation light path, introducing a laser light source, collimating, power adjusting, polarization regulating and spot size modulating, and focusing the light to a micro region of the sample; a light power meter is used for real-time monitoring and collecting data, and then exiting the light path; the microscopic imaging layer (5), the wide-field light excitation layer (6) and the point focusing light excitation layer (7) are respectively realized by independent light path switching mechanisms to realize single operation, and simultaneously realize combined operation by relying on the functional complementarity, wherein the microscopic imaging layer (5) is used for firstly imaging and positioning the sample, determining a target region, then switching to the wide-field light excitation layer (6) or the point focusing light excitation layer (7), and then performing light excitation and detecting photocurrent on the positioned region, and repeating imaging confirmation.

2. The photocurrent microscopy device with light modulation and real-time monitoring function according to claim 1, wherein, the microscopic imaging layer (5) comprises a first linear motor (51), a first beam splitter (52), a tube lens (53), a camera (54), a first reflecting mirror (55), a first achromatic lens (56), a filter (57), a second achromatic lens (58) and a halogen lamp (59).

3. The photocurrent microscopy device with light modulation and real-time monitoring function according to claim 2, characterized in that, broadband light emitted by the halogen lamp (59) is collimated by the second achromatic lens (58), filtered by the filter (57), reflected by the first reflecting mirror (55), focused to a back focal plane of the objective lens (4) by the first achromatic lens (56), and sample light returned by the objective lens (4) is reflected to the tube lens (53) by the first beam splitter (52), and finally imaged on the camera (54).

4. The photocurrent microscopy device with light modulation and real-time monitoring function according to any one of claims 1-3, characterized in that, the wide-field light excitation layer (6) comprises a wide-field light source module, a first power adjusting module, a first polarization adjusting module and a first microscopic projection module; the wide-field light source module comprises a first optical fiber adapter (681), an optical fiber light guide beam (682), a second optical fiber adapter (683) and a single-wavelength LED (69), the single-wavelength LED (69) is connected with one end of the optical fiber light guide beam (682) through the second optical fiber adapter (683), and the other end of the optical fiber light guide beam (682) introduces light into the wide-field light excitation layer (6) through the first optical fiber adapter (681); The first power adjustment module comprises a first rotary motor (612), a first filter disc (613), a fourth achromatic lens (632), a first optical power meter (66) and a second beam splitter (67), the fourth achromatic lens (632) collimates the light emitted by the wide-field light source module into parallel light, the first rotary motor (612) drives the first filter disc (613) to rotate to adjust the optical power, and the second beam splitter (67) transmits part of the light to the first optical power meter (66) for real-time monitoring. The first polarization adjustment module comprises a first half-wave plate (651), a first polarizer (652) and a second rotary motor (653), the second rotary motor (653) drives the first half-wave plate (651) to rotate, and the polarization state of the light is adjusted by changing the included angle between the first half-wave plate (651) and the first polarizer (652). The first microscopic projection module comprises a second linear motor (611), a second reflector (621), a third reflector (622), a third achromatic lens (631) and a diaphragm (64), the diaphragm (64) is used for modulating the shape of the light spot, and the second linear motor (611) drives the second reflector (621) to move to realize the cutting-in / cutting-out of the wide-field light excitation layer (6) light path.

5. The photocurrent microscopy device with light modulation and real-time monitoring function according to any one of claims 1-3, characterized in that, The wide-field light source module can realize the switching of the excitation wavelength by replacing single-wavelength LEDs (69) of different wavelengths, or using multi-color LEDs, or multi-fiber beam combining.

6. The photocurrent microscopy device with light modulation and real-time monitoring function according to claim 4, wherein, The diaphragm (64) adjusts the shape of the light spot by replacing any one of the field diaphragm, the electric pinhole diaphragm, the slit and the spatial light modulator.

7. The photocurrent microscopy device with light modulation and real-time monitoring function according to any one of claims 1-3, characterized in that, The point focusing light excitation layer (7) comprises a laser light source module, a second power adjustment module, a second polarization adjustment module and a second microscopic projection module. The laser light source module comprises a third optical fiber adapter (77) and a fiber laser (78), and the fiber laser (78) introduces laser into the point focusing light excitation layer (7) through the third optical fiber adapter (77); The second power adjustment module comprises a seventh reflector (714), a seventh achromatic lens (723), a third rotary motor (732), a second filter disc (733), a second optical power meter (75) and a third beam splitter (76), the seventh achromatic lens (723) collimates the laser into parallel light, the third rotary motor (732) drives the second filter disc (733) to rotate to adjust the optical power, and the third beam splitter (76) transmits part of the light to the second optical power meter (75) for real-time monitoring. The second polarization adjustment module comprises a sixth reflector (713), a second half-wave plate (741), a second polarizer (742) and a fourth rotary motor (743), the fourth rotary motor (743) drives the second half-wave plate (741) to rotate, and the polarization state of the light is adjusted by changing the included angle between the second half-wave plate (741) and the second polarizer (742). The first polarization adjustment module comprises a first half-wave plate (651), a first polarizer (652) and a second rotary motor (653), the second rotary motor (653) drives the first half-wave plate (651) to rotate, and the polarization state of the light is adjusted by changing the included angle between the first half-wave plate (651) and the first polarizer (652). The second micro-projection module comprises a fourth mirror (711), a fifth mirror (712), a fifth achromatic lens (721), a sixth achromatic lens (722), a third linear motor (731) and a fourth linear motor (715), the third linear motor (731) drives the sixth achromatic lens (722) to move along the light propagation direction, and adjusts the spot size by changing the relative position of the sixth achromatic lens (722) and the fifth achromatic lens (721), and the fourth linear motor (715) drives the fourth mirror (711) to move to realize the in-out of the point focusing light excitation layer (7) light path.

8. A photo-current microscopy modulation method using the apparatus of any one of claims 1-7, characterized in that, The method comprises the following steps: S100: device initialization, placing the sample and preliminary positioning under the objective lens (4) by the displacement table; S200: micro-imaging layer (5) operation, cut into the observation light path, halogen lamp (59) illuminates the sample through the Kohler illumination light path, camera (54) imaging positioning target area, recording coordinates and then exiting the light path; S300: wide-field light excitation layer (6) operation, cut into the observation light path, introduce LED light source, collimate, power regulation, polarization control and spot modulation, project to the sample; the first optical power meter (66) monitors in real time, collects data and then exits the light path; S400: point focusing light excitation layer (7) operation, cut into the observation light path, introduce laser light source, collimate, power regulation, polarization control and spot size modulation, focus to the sample micro area; the second optical power meter (75) monitors in real time, collects data and then exits the light path; S500: cooperative operation, first positioning through the micro-imaging layer (5), then switch to the wide-field light excitation layer (6) / point focusing light excitation layer (7) to excite and test the positioning area, repeat imaging confirmation; S600: end operation, turn off the light source, reset the light path, take out the sample, save the data and check the equipment state.

9. Photocurrent microscopy modulation method according to claim 8, characterized in that, In step S300, when the wide-field light excitation layer (6) operates, the light emitted by the LED light source is transmitted through the optical fiber light guide (682), collimated by the fourth achromatic lens (632), and the power is adjusted by the first filter disc (613). Part of the light is transmitted to the first optical power meter (66) for monitoring through the second beam splitter (67), and the remaining light is controlled by the first polarization adjustment module, the aperture element (64) modulates the spot shape, reflected by the third mirror (622), focused by the third achromatic lens (631), reflected by the second mirror (621) to the back focal plane of the objective lens (4), and finally projected to the sample surface in the form of parallel light.

10. The photogalvanometric modulation method according to claim 8, characterized in that, In step S400, when the point focusing light excitation layer (7) is working, the laser emitted by the fiber laser (78) is collimated by the seventh achromatic lens (723), reflected by the seventh mirror (714), and the power is adjusted by the second filter disc (733). Part of the light is transmitted to the second optical power meter (75) for monitoring through the third beam splitter (76), and the remaining light is reflected by the sixth mirror (713), the polarization state is adjusted by the second polarization adjustment module, and then the spot size is adjusted by the sixth achromatic lens (722) and the fifth achromatic lens (721). After that, the light is reflected by the fifth mirror (712) and the fourth mirror (711) in turn to the objective lens (4), and is focused as a point spot to project onto the sample micro area.

Images