Adjustable laser homogenization microscopy system and modulation method

Abstract

This invention belongs to the field of micro-area photoelectric detection and laser processing technology, specifically a tunable laser homogenization microscopy system and modulation method. The system includes: a laser homogenization module composed of a dual microlens array mounted on a linear motor that can be moved out of the optical path, enabling bidirectional switching between a square flat-top spot and a Gaussian spot; a variable laser beam expander module employing a lens group structure, continuously changing the spot size by adjusting the axial position of the lenses; an XY adjustable frame and a rotation adjustment frame within the laser homogenization module, achieving precise alignment between the microlens arrays to adjust the flat-top spot size; and a laser speckle suppressor driving a scattering sheet to perform high-frequency reciprocating motion via a linear motor to suppress speckle. This invention integrates homogenization, zoom beam expansion, speckle suppression, and microscopic imaging, offering advantages such as flexible spot mode switching, continuously adjustable spot size, excellent speckle suppression effect, and high integration. It can be widely applied in laser processing, biological imaging, optical communication, and other fields.

Description

Technical Field

[0001] This invention relates to the field of micro-area photoelectric detection and laser processing technology, and in particular to an adjustable laser homogenization microscopy system and modulation method. Background Technology

[0002] In cutting-edge fields such as laser processing, display illumination, bioimaging, and optical communication, beam quality is a core indicator that directly determines system efficiency, accuracy, and stability, and is crucial throughout the entire application process. Among these, micro-area observation and micro / nano-fabrication technologies in bioimaging place particularly stringent requirements on beam characteristics: laser microscopy requires precise targeting of cells, subcellular structures, or microscale structures, avoiding high-intensity light damage to the sample while ensuring uniform illumination and imaging resolution within the micro-area; micromanipulation techniques such as laser micro-cutting and optogenetic stimulation rely even more heavily on precise and controllable beam energy distribution, with beam quality directly determining experimental success rates and sample protection effectiveness.

[0003] Gaussian beams and flat-top beams have different suitable applications. Gaussian beams have a Gaussian intensity distribution, concentrated energy, and good collimation, requiring no additional shaping. They are suitable for applications requiring high-energy focusing, such as laser marking, precision cutting, and laser medicine. Flat-top beams, achieved through homogenization technology, have a uniform energy distribution and clear edges, avoiding the energy unevenness problem of Gaussian beams. They are suitable for applications requiring uniform energy, such as large-area laser welding, laser projection, and bioimaging. The two complement each other, supporting technological applications in different fields. The process of transforming a Gaussian beam into a flat-top beam with uniform energy distribution and clear edges is called "beam homogenization" or "beam shaping" in optics.

[0004] Among the many beam homogenization techniques currently available, microlens arrays (MLAs) have become one of the mainstream solutions widely adopted by industry and academia due to their advantages such as compact structure, small size, high energy conversion efficiency, controllable manufacturing cost, and compatibility with various wavelength lasers. However, existing technologies still have the following shortcomings: (1) Most systems can only work in a single spot mode and cannot flexibly switch between flat-top and Gaussian spots according to actual needs; (2) Adjusting the spot size usually requires replacing optical components, which is cumbersome and has a limited adjustment range; (3) The laser speckle suppression effect is poor or introduces additional optical path distortion; (4) The homogenization, beam expansion, and imaging functional modules are scattered, resulting in low system integration. Summary of the Invention

[0005] This invention proposes an adjustable laser homogenization microscopy system and modulation method, aiming to solve the technical problems of existing laser microscopy systems, such as single spot mode, inconvenient spot size adjustment, insufficient speckle suppression, and low system integration.

[0006] In a first aspect, the present invention provides a tunable laser homogenization microscopy system, comprising, sequentially arranged along the laser optical path output from a fiber laser:

[0007] Fiber collimator for collimating laser light into parallel light output, laser speckle suppressor for suppressing laser speckle through a moving scattering plate, laser homogenization module, variable laser beam expander module, and beam splitter for transmitting illumination light and reflecting sample signal light.

[0008] An objective lens is positioned in the optical path after transmission through the beam splitter to focus the light beam onto the sample surface and collect the sample signal light.

[0009] An imaging module includes a reflector, an imaging tube, and a camera. The reflector is positioned on the optical path after being reflected by the beam splitter and is used to guide the signal light to the imaging tube. The imaging tube is used to focus the signal light onto the camera for imaging.

[0010] The laser homogenization module includes a microlens array one and a microlens array two arranged sequentially along the optical path. The entire laser homogenization module can be moved into or out of the optical path. When it is moved into the optical path, the relative position and rotation direction of the microlens array one and the microlens array two can be adjusted to homogenize the incident Gaussian spot into a square flat-top spot and adjust its size.

[0011] The variable laser beam expander module includes at least one lens that can move along the optical path direction for continuously adjusting the beam expansion ratio of the emitted beam to change the size of the focused spot.

[0012] The technical advantages of the adjustable laser homogenization microscopy system disclosed in this invention are: flexible switching between flat-top and Gaussian spot sizes is achieved through a movable / removable dual microlens array homogenization module; continuous adjustment of spot size is achieved through a variable focus beam expander module; speckle is suppressed by driving the scattering sheet to perform ultra-small amplitude high-frequency reciprocating motion through a linear motor; and the above modules are integrated with the microscopic imaging optical path, which has the advantages of compact structure, comprehensive functions, flexible adjustment, and strong adaptability.

[0013] Furthermore, in the laser speckle suppressor, the scattering plate is installed in the cage-plate frame, and the cage-plate frame is connected to the slide of the linear motor through the cage-plate adapter; the linear motor drives the scattering plate to reciprocate in the X-axis direction perpendicular to the optical path propagation direction.

[0014] Furthermore, in the laser homogenization module: microlens array one is installed in an XY adjustable frame, and its relative position in the X and Y directions is adjusted by the X-axis adjustment knob and the Y-axis adjustment knob; microlens array two is installed in a rotary adjustment frame, and its rotation direction is adjusted by the rotation axis θ of the rotary adjustment frame; the rotary adjustment frame, the cage plate adapter, and the XY adjustable frame are connected by a cage rod; the cage plate adapter is connected to a linear motor, so that the laser homogenization module as a whole moves into or out of the optical path.

[0015] Furthermore, in the variable laser beam expander module: lens one, lens two, lens three, and lens four are respectively installed in the cage plate frame, and each cage plate frame is connected by a cage rod; keep the positions of lens two and lens three fixed, and adjust the relative position of lens four on the cage rod to change the focal length of the combined lens.

[0016] Furthermore, in the imaging module, the beam splitter is used to transmit illumination light and reflect sample signal light; the signal light on the sample stage is collected by the objective lens, reflected by the beam splitter, reflected by the mirror, focused by the imaging tube, and then imaged onto the camera.

[0017] Furthermore, when the laser homogenization module moves into the optical path, the system is in a square flat-top spot homogenization mode; when the laser homogenization module is completely moved out of the optical path, the system is in a Gaussian spot mode; in the Gaussian spot mode, the variable laser beam expander module works with the objective lens to focus the laser beam into the smallest spot when the laser is incident on the rear focal plane of the objective lens in a parallel state, and the focused spot becomes larger when the laser is incident in a non-parallel state. The size of the Gaussian spot is continuously adjusted by the continuous movement of the lens four.

[0018] Furthermore, the system also includes a base plate, a microscopy system support, a sample stage, a two-dimensional scanning stage, and a lifting stage; the sample stage is mounted on the two-dimensional scanning stage, the two-dimensional scanning stage is mounted on the lifting stage, the lifting stage is mounted on the microscopy system support, and the microscopy system support is fixed to the base plate.

[0019] Furthermore, the output port of the fiber laser is fixed to the fiber flange, and the fiber flange and the collimating lens form a fiber collimator.

[0020] Furthermore, the scattering plate of the laser speckle suppressor is driven by a linear motor to perform ultra-small amplitude high-frequency reciprocating motion. By utilizing the random scattering of light by the scattering plate, the speckle and interference light spots during laser propagation are averaged.

[0021] Secondly, the present invention provides a modulation method based on the aforementioned tunable laser homogenization microscopy system, comprising the following steps:

[0022] Step S1, Laser Introduction and Collimation: Connect the fiber port of the fiber laser to the fiber flange, and collimate it into parallel light output through the collimating lens;

[0023] Step S2, Laser Speckle Suppression: The parallel light is incident on the laser speckle suppressor, and a linear motor is used to drive the scattering plate to perform ultra-small amplitude high-frequency reciprocating motion in the X-axis direction perpendicular to the light path propagation direction. Through random scattering, the speckle and interference light spots in the laser propagation process are averaged.

[0024] Step S3, Spot Mode Selection: When a square flat-top spot is required, the laser homogenization module is moved into the optical path by a linear motor; when a Gaussian spot is required, the laser homogenization module is completely moved out of the optical path by a linear motor.

[0025] Step S4, Laser Homogenization: When the laser homogenization module is moved into the optical path, the laser passes through microlens array one and microlens array two in sequence. The position of microlens array one in the X and Y axes is adjusted by the XY adjustable frame, and the rotation angle θ of microlens array two along the Z axis is adjusted by the rotating adjustable frame, so that the microlenses in microlens array one and microlens array two are completely aligned, and the homogenized output of the square flat-top light spot is achieved; the size of the flat-top light spot is adjusted by changing the fixed position of the rotating adjustable frame on the cage rod.

[0026] Step S5, Variable beam expansion and spot size adjustment: The parallel light or homogenized beam enters the variable laser beam expansion module and passes through lens one, lens two, lens three and lens four in sequence. Lens two, lens three and lens four are combined into a combined lens. The positions of lens two and lens three are kept fixed, and lens four is adjusted to move along the light path propagation direction to change the focal length of the combined lens, so as to realize the continuous adjustment of the laser beam magnification expansion and spot size.

[0027] Step S6, Beam Focusing and Sample Illumination: After the beam is expanded, it is transmitted through the beam splitter and then incident on the back focal plane of the objective lens. After the objective lens reduces the beam diameter, it is focused onto the surface of the sample to be tested on the sample stage.

[0028] Step S7, Signal Light Imaging: The signal light generated on the sample surface is collected by the objective lens, reflected by the beam splitter, reflected again by the mirror, focused by the imaging tube, and imaged onto the camera to complete the microscopic imaging.

[0029] The technical advantages of the modulation method disclosed in this invention are: it integrates the functions of each module of the above system into a standardized process, forming a complete operational chain from laser input to image output. A highly uniform flat-top light spot can be obtained through precise alignment of the microlens array in step S4; the spot size can be continuously adjusted through continuous movement of lens four in step S5; and speckle can be effectively suppressed and imaging quality improved through high-frequency movement of the scattering sheet in step S2. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of an adjustable laser homogenization microscopy system proposed in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the optical path of the adjustable laser homogenization microscopy system provided in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the optical path and adjustment device for the square spot homogenization mode provided in an embodiment of the present invention;

[0033] Figure 4 This is a top view of the homogenizing optical path and adjustment device provided in an embodiment of the present invention;

[0034] Figure 5 This is a side view of the homogenizing optical path and adjustment device provided in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the Gaussian spot mode optical path and adjustment mechanism provided in an embodiment of the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] To address the technical problems mentioned in the background section regarding existing laser microscopy systems, such as limited spot patterns, inconvenient spot size adjustment, insufficient speckle suppression, and low system integration, this invention provides an adjustable laser homogenization microscopy system. (Refer to...) Figures 1 to 6 As shown, the specific steps include:

[0038] The system in this embodiment includes a base plate 1, a microscopy system support 2, a sample stage 31, a two-dimensional scanning stage 32, a lifting stage 33, an objective lens 4, an imaging module 5, an adjustable laser homogenization system 6, an optical fiber collimator 7, and an optical fiber laser 8. The output port of the optical fiber laser 8 is fixed to an optical fiber flange 71, and then collimated into parallel light by a collimating lens 72. The parallel light passes sequentially through a scattering plate 631, a microlens array 1 621, a microlens array 2 622, a lens 1 611, a lens 2 612, a lens 3 613, a lens 4 614, and a beam splitter 51, finally incident on the back focal plane of the objective lens 4. After the objective lens 4 reduces the beam diameter, the light is incident on the sample stage 31. The signal light on the sample stage 31 is collected by the objective lens 4, partially reflected by the beam splitter 51, then reflected by the reflecting mirror 52, focused by the imaging tube 53, and finally imaged onto the camera 54.

[0039] The laser speckle suppressor 63 includes a scattering plate 631, a cage-plate mirror frame 632, a cage-plate adapter 634, and a linear motor 633. The scattering plate 631 is mounted in the cage-plate mirror frame 632, which is connected to the slide of the linear motor 633 via the cage-plate adapter 634. The scattering plate 631 is fixed on the linear motor 633, causing it to maintain a high-frequency reciprocating motion with an ultra-small amplitude in the X-axis direction. Through the random scattering of light by the scattering plate, the speckle and interference spots during laser propagation are averaged.

[0040] The laser homogenization module 62 includes a first microlens array 621 and a second microlens array 622. The first microlens array 621 is mounted in an XY adjustable frame 625, and its relative position in the X and Y directions can be precisely adjusted using X-axis adjustment knobs 6251 and 6252. The second microlens array is mounted in a rotary adjustment frame 626, and the rotation direction of its components is adjusted by the rotation axis θ of the rotary adjustment frame 626. The rotary adjustment frame 626, the cage plate adapter 624, and the XY adjustable frame 625 are connected by a cage rod 627. By fine-tuning the XY adjustment frame 625 in the X and Y directions and fine-tuning the rotation axis θ of the rotary adjustment frame 626, the microlenses in the first microlens array 621 and the second microlens array 622 are perfectly aligned, ensuring the beam homogenization effect of the square light spot. By changing the fixed position of the rotating adjustment frame 626 on the cage rod 627, the size of the homogenized beam can be adjusted. The cage plate adapter 624 is connected to the linear motor 623, allowing the entire laser homogenization module 62 to be moved out of the optical path, realizing the switching between square spot homogenization mode and Gaussian spot mode.

[0041] The variable laser beam expander module 61 includes lens 1 611, lens 2 612, lens 3 613, and lens 4 614. Lenses 1 611, 2 612, 3 613, and 4 614 are respectively installed in cage-plate mirror frames 615, 616, 617, and 618, and are connected by cage rods 619. Lenses 2 612, 3 613, and 4 614 are used as a combined lens. By fixing the positions of lenses 2 612 and 3 613 and adjusting the relative position of lens 4 614 on the cage rod 619, the focal length of the combined lens can be changed. Lens 1 611 and the combined lens together form the variable laser beam expander module 61. Objective lens 4 works in conjunction with variable laser beam expander module 61. When the laser beam is incident on objective lens 4 in a parallel state, the focal plane focuses the smallest spot onto the sample stage 31. When the laser beam is incident on objective lens 4 in a non-parallel state, the focal plane focuses the spot larger. The spot size can be continuously adjusted by continuously moving lens 4 614.

[0042] Imaging module 5 includes a beam splitter 51, a reflector 52, an imaging tube 53, and a camera 54. The beam, after being homogenized or expanded, is transmitted through the beam splitter 51 and then incident on the back focal plane of the objective lens 4. The signal light on the sample stage 31 is collected by the objective lens 4, reflected by the beam splitter 51, reflected again by the reflector 52, focused by the imaging tube 53, and then imaged onto the camera 54.

[0043] Based on the same inventive concept, this invention also provides a modulation method based on the aforementioned tunable laser homogenization microscopy system, comprising the following steps:

[0044] Step S1, Laser introduction and collimation: Connect the fiber port of the fiber laser 8 to the fiber flange 71, and collimate it into parallel light output through the collimating lens 72.

[0045] Step S2, Laser Speckle Suppression: Parallel light is incident on the laser speckle suppressor 63, and the scattering plate 631 is driven by the linear motor 633 to perform ultra-small amplitude high-frequency reciprocating motion in the X-axis direction. Through random scattering, the speckle and interference light spot are averaged.

[0046] Step S3, Spot mode selection: When a square flat-top spot is needed, the laser homogenization module 62 is moved into the optical path by the linear motor 623; when a Gaussian spot is needed, the laser homogenization module 62 is completely moved out of the optical path by the linear motor 623.

[0047] Step S4, Laser homogenization: When the laser homogenization module 62 moves into the optical path, the laser passes sequentially through microlens array one 621 and microlens array two 622. The position of microlens array one 621 in the X-axis and Y-axis directions is adjusted by the XY adjustable frame 625, and the rotation angle θ of microlens array two 622 is adjusted by the rotating adjustment frame 626 to make the microlenses completely aligned, thereby achieving homogenized output of the square flat-top light spot. The size of the flat-top light spot is adjusted by changing the fixed position of the rotating adjustment frame 626 on the cage rod 627.

[0048] Step S5, Variable beam expansion and spot size adjustment: The parallel or homogenized beam enters the variable laser beam expansion module 61 and passes through lens one 611, lens two 612, lens three 613 and lens four 614 in sequence. Keep the positions of lens two 612 and lens three 613 fixed, and adjust lens four 614 to move along the Z-axis to change the focal length of the combined lens, so as to realize the continuous adjustment of the laser beam magnification expansion and spot size.

[0049] Step S6, Beam Focusing and Sample Illumination: After the beam is expanded, it is transmitted through the beam splitter 51 and then incident on the back focal plane of the objective lens 4. After the beam diameter is reduced by the objective lens 4, it is focused onto the surface of the sample to be tested on the sample stage 31.

[0050] Step S7, Signal light imaging: The signal light generated on the sample surface is collected by the objective lens 4, reflected by the beam splitter 51, reflected by the mirror 52, focused by the imaging tube lens 53 and imaged onto the camera 54 to complete the microscopic imaging.

[0051] Beneficial effects:

[0052] (1) Achieve flexible switching of spot modes to adapt to the needs of multiple application scenarios. The present invention uses a linear motor to drive the laser homogenization module to move out of the optical path as a whole, which can quickly achieve bidirectional switching between square flat-top spot and Gaussian spot. The flat-top spot has uniform energy distribution and clear edges, which is suitable for scenarios that require uniform energy, such as bio-imaging and large-area laser welding. The Gaussian spot has concentrated energy and good collimation, which is suitable for scenarios that require high energy focusing, such as laser marking and precision cutting. No additional equipment replacement is required, which greatly improves the versatility and adaptability of the system.

[0053] (2) The spot size is continuously adjustable, with high adjustment accuracy and convenient operation. The variable laser beam expander module can change the focal length of the combined lens by adjusting the relative position of lens 4 on the cage rod, and achieve continuous adjustment of the Gaussian spot size in conjunction with the objective lens; at the same time, by adjusting the fixed position of the rotating adjustment frame on the cage rod, the size of the flat-top spot can be flexibly adjusted. The adjustment process does not require disassembling optical components, the operation is simple, and the adjustment accuracy can meet the requirements of high-precision scenarios such as micro-area photoelectric detection and micro-nano processing.

[0054] (3) Effectively suppresses laser speckle and improves beam quality and imaging effect. The laser speckle suppressor drives the scattering plate to perform ultra-small amplitude high-frequency reciprocating motion in the X-axis direction through a linear motor. By utilizing the random scattering effect of the scattering plate on the laser, the speckle and interference spot in the laser propagation process are averaged, which significantly reduces the impact of speckle on beam quality. Especially in biological imaging scenarios, it can effectively improve imaging clarity and contrast and avoid observation errors caused by speckle interference.

[0055] (4) The system has high integration, compact structure, low energy consumption and strong practicality. The microlens array is used as the core component of laser homogenization. Its structure is compact and small in size. It can be efficiently integrated with variable laser beam expander module, speckle suppression module and microscopic imaging system, which is convenient for miniaturized optoelectronic devices. At the same time, the microlens array has high energy conversion efficiency, which can minimize beam energy loss and reduce system energy consumption. It is also compatible with multiple wavelength lasers, and the manufacturing cost is controllable. It can be widely used in many high-precision fields such as laser processing, biological imaging and optical communication.

[0056] (5) The optical path adjustment is precise and controllable, and the stability is strong. Each optical component is equipped with a dedicated adjustment mechanism. For example, the microlens array can achieve high-precision fine adjustment in the X and Y directions through the XY adjustable frame, and achieve fine adjustment of the rotation direction through the rotating adjustment frame, so as to ensure the precise alignment of the microlenses to ensure the homogenization effect. Each adjustment mechanism is connected by components such as cage rods and cage plates, which are structurally stable and can effectively avoid optical path deviation, thereby improving the stability and reliability of the system in long-term operation.

[0057] (6) It combines laser homogenization and microscopic imaging functions to achieve integrated operation. The system organically combines the adjustable laser homogenization system and the microscopic imaging system. The homogenized laser can directly provide uniform illumination for microscopic imaging. The signal light on the sample platform can be collected by the objective lens and processed by the imaging module to achieve real-time imaging. There is no need to build additional lighting and imaging equipment, realizing integrated operation of "homogenization-illumination-imaging", simplifying equipment layout and improving operation efficiency.

[0058] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. An adjustable laser homogenization microscopy system, comprising: The laser beam path output from the fiber laser (8) includes, in sequence: Fiber collimator (7) for collimating laser light into parallel light output, laser speckle suppressor (63) for suppressing laser speckle through a moving scattering plate, laser homogenization module (62), variable laser beam expander module (61), and beam splitter (51) for transmitting illumination light and reflecting sample signal light. Objective lens (4) is placed in the optical path after transmission through the beam splitter (51) to focus the light beam onto the sample surface and collect the sample signal light; The imaging module (5) includes a reflector (52), an imaging tube (53) and a camera (54). The reflector (52) is disposed on the optical path after being reflected by the beam splitter (51) and is used to guide the signal light to the imaging tube (53). The imaging tube (53) is used to focus the signal light onto the camera (54) for imaging. The laser homogenization module (62) includes a microlens array one (621) and a microlens array two (622) arranged sequentially along the optical path. The laser homogenization module (62) as a whole can be moved into or out of the optical path. When it is moved into the optical path, the relative position and rotation direction of the microlens array one (621) and the microlens array two (622) can be adjusted to homogenize the incident Gaussian spot into a square flat-top spot and adjust its size. The variable laser beam expander module (61) includes at least one lens that can move along the optical path direction for continuously adjusting the beam expansion ratio of the emitted beam to change the size of the focused spot.

2. The tunable laser homogenization microsystem of claim 1, wherein, In the laser speckle suppressor (63), the scattering plate (631) is installed in the cage plate frame (632), and the cage plate frame (632) is connected to the slide of the linear motor (633) through the cage plate adapter (634); the linear motor (633) drives the scattering plate (631) to reciprocate in the X-axis direction perpendicular to the direction of light propagation.

3. The tunable laser homogenization microscopy system according to claim 1, characterized in that, In the laser homogenization module (62): microlens array one (621) is installed in the XY adjustable frame (625), and its relative position in the X and Y directions is adjusted by the X-axis adjustment knob (6251) and the Y-axis adjustment knob (6252); microlens array two (622) is installed in the rotary adjustment frame (626), and its rotation direction is adjusted by the rotation axis θ of the rotary adjustment frame (626); the rotary adjustment frame (626), the cage plate adapter (624), and the XY adjustable frame (625) are connected by the cage rod (627); the cage plate adapter (624) is connected to the linear motor (623) so that the laser homogenization module (62) moves into or out of the optical path as a whole.

4. The tunable laser homogenization microscopy system according to claim 1, characterized in that, In the variable laser beam expander module (61): lens one (611), lens two (612), lens three (613), and lens four (614) are respectively installed in the cage plate lens frame (615, 616, 617, 618), and each cage plate lens frame is connected by a cage rod (619); keep the positions of lens two (612) and lens three (613) fixed, and adjust the relative position of lens four (614) on the cage rod (619) to change the focal length of the combined lens.

5. The tunable laser homogenization microscopy system according to claim 1, characterized in that, In the imaging module (5), the beam splitter (51) is used to transmit illumination light and reflect sample signal light; the signal light on the sample stage (31) is collected by the objective lens (4) and reflected by the beam splitter (51), then reflected by the mirror (52), focused by the imaging tube lens (53) and imaged onto the camera (54).

6. The tunable laser homogenization microscopy system according to claim 1, characterized in that, When the laser homogenization module (62) moves into the optical path, the system is in the square flat-top spot homogenization mode; when the laser homogenization module (62) is completely moved out of the optical path, the system is in the Gaussian spot mode; in the Gaussian spot mode, the variable laser beam expander module (61) cooperates with the objective lens (4) to focus the laser into the smallest spot when the laser is incident on the back focal plane of the objective lens (4) in parallel light, and the focused spot becomes larger when the laser is incident in a non-parallel state. The size of the Gaussian spot is continuously adjusted by the continuous movement of the lens four (614).

7. The tunable laser homogenization microscopy system according to claim 1, characterized in that, The system also includes a base plate (1), a microscopy system support (2), a sample stage (31), a two-dimensional scanning stage (32), and a lifting stage (33); the sample stage (31) is mounted on the two-dimensional scanning stage (32), the two-dimensional scanning stage (32) is mounted on the lifting stage (33), the lifting stage (33) is mounted on the microscopy system support (2), and the microscopy system support (2) is fixed on the base plate (1).

8. The tunable laser homogenization microscopy system according to claim 1, characterized in that, The output port of the fiber laser (8) is fixed to the fiber flange (71), and the fiber flange (71) and the collimating lens (72) form a fiber collimator (7).

9. The tunable laser homogenization microscopy system according to claim 1, characterized in that, The scattering plate (631) of the laser speckle suppressor (63) is driven by a linear motor (633) to perform ultra-small amplitude high-frequency reciprocating motion. By utilizing the random scattering of light by the scattering plate, the speckle and interference light spots in the laser propagation process are averaged.

10. A modulation method for a tunable laser homogenization microscopy system based on any one of claims 1 to 9, characterized in that, Includes the following steps: Step S1, Laser introduction and collimation: Connect the fiber port of the fiber laser (8) to the fiber flange (71), and collimate it into parallel light output through the collimating lens (72); Step S2, Laser speckle suppression: The parallel light is incident on the laser speckle suppressor (63), and the scattering plate (631) is driven by the linear motor (633) to perform ultra-small amplitude high frequency reciprocating motion in the X-axis direction perpendicular to the light path propagation direction. Through random scattering, the speckle and interference light spots in the laser propagation process are averaged. Step S3, Spot mode selection: When a square flat-top spot is needed, the laser homogenization module (62) is moved into the optical path by the linear motor (623); when a Gaussian spot is needed, the laser homogenization module (62) is completely moved out of the optical path by the linear motor (623). Step S4, Laser homogenization: When the laser homogenization module (62) moves into the optical path, the laser passes through microlens array one (621) and microlens array two (622) in sequence. The position of microlens array one (621) in the X-axis and Y-axis directions is adjusted by the XY adjustable frame (625). At the same time, the rotation angle θ of microlens array two (622) along the Z-axis is adjusted by the rotating adjustment frame (626) so that the microlenses in microlens array one (621) and microlens array two (622) are completely aligned, so as to achieve homogenization output of square flat-top light spot. The size of flat-top light spot is adjusted by changing the fixed position of the rotating adjustment frame (626) on the cage rod (627). Step S5, Variable beam expansion and spot size adjustment: The parallel light or homogenized beam enters the variable laser beam expansion module (61) and passes through lens one (611), lens two (612), lens three (613) and lens four (614) in sequence. Among them, lens two (612), lens three (613) and lens four (614) are combined into a combined lens. The positions of lens two (612) and lens three (613) are kept fixed. Lens four (614) is adjusted to move along the light path propagation direction to change the focal length of the combined lens, so as to realize the continuous adjustment of the laser beam magnification expansion and spot size. Step S6, beam focusing and sample illumination: After the beam is expanded, it is transmitted through the beam splitter (51) and then incident on the back focal plane of the objective lens (4). After the beam diameter is reduced by the objective lens (4), it is focused onto the surface of the sample to be tested on the sample stage (31). Step S7, Signal light imaging: The signal light generated on the sample surface is collected by the objective lens (4), reflected by the beam splitter (51), reflected by the mirror (52), focused by the imaging tube (53) and imaged onto the camera (54) to complete the microscopic imaging.

Images