Laser polishing device and polishing method

Abstract

The invention belongs to the technical field of laser processing. According to the laser polishing device and method, a laser generator is used for generating pulse laser; the focusing and coupling unit is used for focusing and coupling the pulse laser, so that the laser is efficiently transmitted in the optical fiber; the homogenizing optical fiber is used for homogenizing and shaping the laser pulse to obtain a square flat-topped laser spot; the light spot shaping unit is used for controlling the size of the square flat top light spot, so that the laser is coupled into the galvanometer; and the scanning galvanometer is used for controlling the pulse laser and the diamond to move relatively, the distance between the light spots is the diameter of the light spots by controlling the laser scanning speed and the linear distance, and the diamond is scanned and polished on a preset scanning route. By controlling the laser scanning speed and the line spacing, the spacing between the light spots is the diameter of the light spots, so that diamond polishing with uniform energy and high efficiency is realized, and the processing time consumption is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and in particular to a laser polishing apparatus and polishing method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Diamond, as a typical ultrawide bandgap semiconductor material, possesses excellent properties such as an extremely wide bandgap, extremely high thermal conductivity, high carrier mobility, and high breakdown electric field, showing significant potential in the fabrication of high-voltage, high-temperature, high-frequency, high-power, and radiation-resistant devices. With advancements in laser and motion control technologies, ultrafast laser precision machining has become an important method for diamond surface treatment. Its basic principle involves focusing an ultrashort pulse laser onto the diamond surface or subsurface; the material nonlinearly absorbs the light energy and rapidly converts it into heat. When the energy density exceeds its modification threshold, a phase transition or selective removal occurs in the focal region, resulting in micro-region modification. By controlling the laser to scan along a predetermined path using a precision motion system, layer-by-layer, controllable removal of the material surface can be achieved, effectively reducing surface roughness and damage. This method provides a key surface treatment technology for the high-quality fabrication of diamond devices.

[0004] Laser polishing of diamond typically involves using an unshaped circular Gaussian laser spot to polish the diamond surface, adjusting the spot overlap rate to achieve uniform surface planarization. However, in general, circular Gaussian spots often struggle to distribute energy evenly during diamond polishing, significantly increasing the difficulty and reducing polishing quality. Furthermore, the distance between laser spots during polishing usually does not exceed the spot diameter, limiting the laser's scanning speed and line spacing. This results in drawbacks such as long processing time and low efficiency, severely restricting the industrial application of laser polishing technology.

[0005] To address the problem of excessively long processing times, a common solution is to increase the laser scanning speed. However, rapid laser scanning reduces the overlap rate of the laser spots, increases the spacing between spots, and leads to uneven energy distribution, thus reducing surface quality. Another approach is to increase the scanning line spacing, but this spacing has extreme values. Excessive scanning distance reduces the longitudinal overlap rate of the laser spots, decreasing energy uniformity and ultimately lowering polishing quality. Researchers have proposed a device and method for polishing square flat-top laser spots using a spatial light modulator. Specifically, this involves using a spot shaping module and a spot modulation module to modulate the square flat-top laser spot after the laser beam is expanded by the shaping module. The spot shaping module includes a beam expanding module and multiple sub-transfer modules. The beam expanding module matches the beam expanded from the laser generator in the optical path with the modulation module. The sub-transfer modules guide the laser pulse to the spot modulation module. However, this method is relatively complex, requiring multiple sub-transfer modules to be set up according to requirements, making the device larger and less suitable for industrial applications. Furthermore, the spot modulation module has high costs and a low damage threshold, resulting in high costs for subsequent maintenance and component procurement, further hindering industrial application. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a laser polishing device and method. The device uses a homogenizing fiber to homogenize and shape the laser spot, and then obtains a square flat-top laser spot of controllable size on the focal plane through a lens group. By controlling the laser scanning speed and the line spacing, the distance between the laser spots is made equal to the diameter of the laser spot, thus achieving uniform energy and high-efficiency diamond polishing, which greatly reduces the processing time.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a laser polishing apparatus.

[0008] A laser polishing apparatus includes: a laser generator, a focusing coupling unit, a homogenizing fiber, a spot shaping unit, and a scanning galvanometer. A laser generator is used to produce pulsed laser light. The focusing coupling unit is used to focus and couple the pulsed laser, enabling the laser to be transmitted efficiently in the optical fiber. Homogenizing fiber is used to homogenize and shape laser pulses to obtain a square-topped laser spot. The spot shaping unit is used to control the size of the square flat-top spot so that the laser is coupled into the galvanometer. The scanning galvanometer is used to control the relative motion between the pulsed laser and the diamond. By controlling the laser scanning speed and the line spacing, the distance between the laser spots is equal to the diameter of the laser spots, and the diamond is scanned and polished along the preset scanning path.

[0009] In one implementation of the first aspect of the present invention, the diamond is placed on a stage, and the scanning galvanometer is used to control the scanning speed of the pulsed laser, the scanning line spacing, and the relative position between the laser and the diamond.

[0010] In one implementation of the first aspect of the present invention, the spot shaping unit is used to adjust the outgoing light from the optical fiber into parallel light and control the spot size to achieve the optimal galvanometer entrance pupil diameter.

[0011] In one implementation of the first aspect of the present invention, the focusing coupling unit is used to adjust the Rayleigh length and divergence angle of the pulsed laser generated by the laser generator after focusing.

[0012] Secondly, the present invention provides a laser polishing method.

[0013] A laser polishing method, utilizing the laser polishing apparatus of the first aspect of the present invention, includes the following processes: Based on the spot spacing required for the close arrangement of square flat-top light spots, determine the laser scanning speed and scanning line spacing required when setting the parameters of the scanning galvanometer, so that the spot spacing is equal to the spot diameter; A lens group is used to shape the pulsed laser to adjust the size of the spot. After the pulsed laser is adjusted into parallel light by the lens group, it is focused by the field lens to form a square flat-top spot, so that each processing area is uniformly scanned by the modulated flat-top pulsed laser. The scanning mirror controls the relative movement of the flat-top pulsed laser with the diamond, completing the scanning and processing of the diamond along a preset path.

[0014] In one implementation of the second aspect of the present invention, before using a lens group to shape the pulsed laser into a flat-top pulsed laser, a focusing coupling unit is used to focus and couple the pulsed laser to obtain a pulsed laser that can be optimally coupled with an optical fiber.

[0015] In one implementation of the second aspect of the present invention, the homogenized optical fiber modulates the incident light by total internal reflection homogenization inside the optical fiber to generate a uniform light spot, and then focuses it through a field lens to form a square flat-top light spot for uniform processing.

[0016] In one implementation of the second aspect of the present invention, the relative spatial position between the focusing coupling unit and the homogenizing optical fiber is adjusted by a three-dimensional displacement stage.

[0017] In one implementation of the second aspect of the present invention, the size of the square flat-top light spot is adjusted so that the polishing effect achieved by a single scan is greater than or equal to the polishing effect of three Gaussian light spots.

[0018] In one implementation of the second aspect of the present invention, the relative position of the pulsed laser and the diamond is adjusted by a scanning galvanometer to control the diamond scanning path and scanning interval. Compared with the prior art, the beneficial effects of the present invention are: This invention achieves uniform scanning processing of diamond using square flat-top laser pulses through the homogenization process of the optical fiber. Furthermore, the relative position between the pulsed laser and the diamond can be adjusted by the scanning galvanometer, thereby controlling the diamond scanning path and scanning interval. This invention can achieve the effect of multiple scanning processing using traditional circular Gaussian pulsed lasers, that is, multiple scanning processes can be achieved with a single scan, reducing the number of scans, greatly reducing processing time, and improving processing efficiency.

[0019] This invention fundamentally changes the non-uniform characteristics of traditional laser polishing, where energy is concentrated at the center of the spot and attenuation is severe at the edges, by introducing a homogenizing fiber to redistribute the energy of the original Gaussian beam. The homogenizing fiber utilizes its internal multiple total internal reflection mechanism to allow the incident laser to undergo sufficient spatial mixing during propagation, resulting in a flat-top beam with a highly uniform energy distribution. This flat-top beam, after being focused by a subsequent spot shaping unit and field lens, forms a square spot with clear boundaries and flat energy. This spot shape not only avoids the uneven processing problem caused by improper overlap control of Gaussian spots but also allows for a close arrangement of adjacent scan lines without redundancy or gaps. Because the energy remains consistent throughout the entire working area, the material removal process is more controllable and stable, significantly improving the consistency and integrity of the polished surface. It is particularly suitable for the precision machining of hard and brittle materials such as diamond, where surface quality requirements are stringent.

[0020] This invention organically combines homogenization shaping with scanning control strategies to construct a highly efficient and collaborative laser polishing mechanism. By precisely setting the scanning speed and line spacing to match the geometry of the square flat-top laser spot (i.e., the spacing equals the spot diameter), it achieves full-coverage, uniform processing with no omissions in a single scan. This strategy eliminates the inefficient mode of traditional Gaussian spots that rely on multiple cross-scans to compensate for uneven energy, significantly simplifying the process. Furthermore, since the energy distribution of the flat-top laser spot is already highly uniform, there is no need to increase the overlap rate to "compensate" for insufficient edge energy, thus significantly increasing the effective processing area per unit time while ensuring processing quality. This method not only reduces excessive reliance on the repeatability accuracy of the motion control system but also reduces the risk of thermal effects and surface damage caused by multiple scans, comprehensively improving the stability, controllability, and industrial applicability of the laser polishing process.

[0021] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 A schematic diagram of a laser polishing apparatus provided as an exemplary embodiment of the present invention; Figure 2 A schematic diagram of a circular Gaussian spot scanning processing path is provided for an exemplary embodiment of the present invention; Figure 3 A schematic diagram of a square flat-top light spot scanning processing path is provided for an exemplary embodiment of the present invention; Among them, 100 is the laser generator; 200 is the focusing coupling unit; 300 is the homogenizing fiber; 400 is the spot shaping unit; 500 is the scanning galvanometer; 600 is the diamond; and 700 is the stage. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0026] This embodiment discloses a laser polishing device based on a homogenized optical fiber 300. The homogenized optical fiber 300 enables pulsed laser light to achieve a square, flat-topped spot for polishing diamond 600, achieving the effect of multiple processing cycles in a single operation under a single light source. Compared to traditional multi-processing methods, the single-processing method significantly reduces processing time.

[0027] Specifically, such as Figure 1 As shown, the laser polishing device of the present invention specifically includes: a laser generator 100, a focusing coupling unit 200, a homogenizing fiber 300, a spot shaping unit 400, a scanning galvanometer 500, a diamond 600, and a stage 700.

[0028] The laser generator 100 is used to generate processing laser pulses with a certain wavelength and repetition frequency; the optical path design unit is used to focus and couple the processing laser generated by the laser generator 100 into an optical fiber to achieve high transmission efficiency of the optical fiber; the homogenizing optical fiber 300 is used to homogenize the laser focused by the focusing and coupling unit 200 into a beam with uniform energy distribution; the spot shaping unit 400 is used to modulate the homogenized laser emitted from the homogenizing optical fiber 300 into parallel light and incident it into the scanning galvanometer 500; by controlling the scanning galvanometer 500, the pulsed laser is scanned in a preset direction, so as to perform scanning processing according to the set route and speed; the traditional laser polishing method is to focus a circular Gaussian spot on the surface of the diamond 600, scan the pulsed laser on the diamond 600 according to the preset path and speed, and after the scanning is completed, scan it multiple times with different scanning speeds and line spacings to finally obtain a reasonable spot overlap rate, as Figure 2 shown, the scanning path is a "ji" shape.

[0029] The high-efficiency diamond laser polishing device based on the homogenizing optical fiber 300 proposed by the present invention performs scanning processing on the diamond 600, as Figure 3 shown, the specific operation process is as follows: the laser generating unit emits laser pulses with a certain wavelength, pulse width, energy, and repetition frequency. After being modulated by the focusing and coupling unit 200, the pulsed laser with a divergence angle, Rayleigh length, and waist radius of the pulsed laser that meet the optical fiber coupling conditions is obtained. The pulsed laser is processed by the homogenizing optical fiber 300 to obtain a pulsed laser beam with uniform energy distribution. As Figure 3 shown in the processing path, the spot shaping unit 400 adjusts the processing laser spot to an appropriate size and focuses it through a field lens. By controlling the scanning galvanometer 500, precise guidance of the spatial position of the pulsed laser with a square flat-top spot can be achieved, and single-time uniform scanning polishing can be realized.

[0030] In the laser polishing device of the present invention, the energy distribution of the initial laser spot can be changed through the homogenizing optical fiber 300, and the size of the square spot is controlled by controlling the lens group. The homogenizing optical fiber 300 is an optical device that can homogenize and shape a beam and can be used to modulate a Gaussian beam into a flat-top beam. The following is a basic method to achieve this goal: Prepare a Gaussian beam, which can be a high-quality beam from a laser. Then, focus the laser beam using a lens and couple it into a homogenizing fiber 300. The homogenizing fiber 300 is typically made of quartz glass or other materials. The transmission efficiency of the fiber can be adjusted by changing the incident spot size, incident angle, and divergence angle of the incident laser. With specific incident and divergence angles, the Gaussian beam can be modulated into a flat-top beam. The energy uniformity of the beam also depends on the incident and divergence angles. Adjust the distance between the fiber's output end and the lens group so that the diverging beam reaches the optimal diameter for lens focusing. Placing a suitable lens system behind the homogenizing fiber 300 can adjust the diverging beam into parallel light. By appropriately adjusting the distance between the lenses, different spot sizes can be achieved.

[0031] It should be noted that the above process only provides a basic description of how to modulate a Gaussian beam into a flat-top beam using homogenizing fiber 300. Specific implementation methods and adjustment steps may vary depending on the actual application and equipment. Furthermore, this invention can meet various processing requirements, increase processing flexibility, and achieve highly efficient diamond 600 polishing without changing the hardware.

[0032] Optionally, in some other implementations, if the scan line spacing is not set appropriately, insufficient or excessive overlap may occur due to a mismatch between the spacing and the spot size, affecting processing efficiency and quality. Therefore, it is necessary to establish a correlation model between the spacing, spot size, and energy uniformity. In view of this, an optimal scan line spacing setting method is proposed as follows: (1); in, Represents the optimal scan line spacing (unit: mm); Represents the side length of a square flat-topped light spot (unit: mm); Represents the uniformity coefficient of light spot energy; Representing the correction coefficient, the optimal scan line spacing enables adaptive calculation of the scan line spacing, ensuring that the longitudinal overlap rate of the light spot matches the energy uniformity. This avoids energy waste and ensures full polishing coverage. The calculated d is input into the scanning galvanometer 500 control system as the core input of the scanning parameters, replacing manual preset and adapting to different size light spots and diamond 600 materials.

[0033] (2); Wherein, represents the laser energy density at coordinates (x, y) within the square laser spot (unit: W / mm²). 2 ); represents the coordinates within the square light spot. Laser energy density at (unit: W / mm) 2 ); represents the maximum energy density within the light spot (unit: W / mm²). 2); represents the minimum energy density within the light spot (unit: W / mm²). 2 ); represents the average energy density within the light spot (unit: W / mm²). 2 ), , Area of ​​the square light spot (unit: mm) 2 ).

[0034] Scanning speed is directly related to spot energy and material removal rate. A fixed speed can easily lead to low processing efficiency or surface damage. Therefore, a speed optimization model needs to be established by combining spot energy and material threshold. Alternatively, among other implementation methods, an alternative to manual control is proposed, including: (3); in, Represents the optimal laser scanning speed (unit: mm / s); Represents the laser pulse width; This represents the laser absorption efficiency of Diamond 600. Represents the threshold energy for modifying Diamond 600 materials; This represents the material removal thickness in a single scan (unit: mm). By setting the optimal laser scanning speed, a precise match is achieved between scanning speed, energy, and removal thickness. This ensures that the target removal effect is achieved in a single scan while avoiding insufficient energy due to excessive speed or over-processing due to excessively slow speed. The optimal laser scanning speed is thus achieved. With the optimal scan line spacing The linkage input scanning galvanometer 500 forms a "speed-spacing" coordinated control parameter to ensure a balance between processing efficiency and quality.

[0035] The laser polishing device based on homogenized optical fiber 300 provided by this invention, compared with the traditional Gaussian spot scanning processing method, only requires one scan of diamond 600, which improves the number of scans and thus significantly shortens the processing time. In addition, reducing the number of scans to a single scan also improves the stability of the processing. Moreover, this invention can control the size and energy of the spot as needed to achieve controlled and selective scanning processing, which greatly improves the processing efficiency. This invention greatly solves the problems of low processing efficiency, long processing time and poor quality in existing processes.

[0036] Based on the aforementioned laser polishing apparatus, this implementation also provides a high-efficiency laser polishing method based on homogenized optical fiber 300, comprising the following processes: Based on the spot spacing required for the close arrangement of square flat-top light spots, determine the laser scanning speed and scanning line spacing required when setting parameters for scanning galvanometer 500; A lens group is used to shape and adjust the size of the pulsed laser spot. After the pulsed laser is adjusted into parallel light by the lens group, it is focused by the field lens to form a square flat-top spot, so that each processing area is uniformly scanned by the modulated flat-top pulsed laser. The scanning galvanometer 500 controls the relative movement between the flat-top pulsed laser and the diamond 600, completing the scanning and processing of the diamond 600 along a preset path. Specifically, the scanning galvanometer 500 adjusts the relative spatial position between the pulsed laser and the diamond 600.

[0037] The scanning galvanometer 500 may experience trajectory deviation due to inertia during high-speed movement, causing the actual scanning path of the light spot to deviate from the preset path, affecting polishing uniformity. Optionally, in some other implementations, this can be compensated for by calculating and optimizing the trajectory deviation, including: (4); (5); in, Represents trajectory deviation (unit: mm); This represents the maximum permissible scanning speed of the galvanometer (unit: mm / s). Represents the coordinates on the preset scan trajectory (unit: mm); Represents the coordinates of the trajectory inflection point (unit: mm); Represents the inertia coefficient of the galvanometer; Represents the actual scan coordinates after compensation (unit: mm); Represents the scanning direction angle (unit: rad), i.e., the trajectory in The tangent direction angle of the point is calculated, and the trajectory deviation is compensated to control the scanning trajectory error within ±0.001mm, ensuring that the light spot scans strictly according to the preset path, improving polishing uniformity, and the compensated coordinates are then used to... The real-time input scanning galvanometer 500 control system replaces the original preset coordinates and dynamically corrects trajectory deviations during high-speed scanning.

[0038] In this implementation, before homogenizing the pulsed laser with the homogenizing fiber 300 to form a flat-top pulsed laser, the pulsed laser is further homogenized with the focusing coupling unit 200 to obtain a pulsed laser with an incident angle and divergence angle that match the fiber.

[0039] The parameters of the focusing coupling unit 200 (Rayleigh length, divergence angle) directly affect the fiber transmission efficiency. Existing solutions do not provide a quantitative optimization method, leading to excessive energy loss and impacting processing efficiency. Therefore, alternatively, in some other implementations, an optimization scheme for focusing coupling efficiency is proposed, including: (6); in, Represents focused coupling efficiency; Represents the laser beam waist radius (unit: mm); Represents the laser divergence angle after focusing (unit: rad); Represents the laser wavelength (unit: mm); Laser Rayleigh length (unit: mm). The focusing coupling unit 200 was optimized by quantifying coupling efficiency. and ,make To minimize energy loss during laser transmission through optical fibers, if The relative positions of the focusing coupling unit 200 and the homogenizing fiber 300 are adjusted by using a three-dimensional displacement stage to correct the... and until The standard is met to ensure that the energy incident on the homogenized fiber 300 meets the processing requirements.

[0040] The homogenized fiber 300 uses total internal reflection technology to homogenize the energy of the incident light, generating a flat-top pulsed laser. The size of the light spot is modulated by adjusting the distance between the lens groups behind the fiber, enabling high-efficiency and rapid processing. The resulting flat-top pulsed light spot can be controlled in size, so that the effect achieved in a single processing is greater than or equal to the effect achieved in three Gaussian spot processing.

[0041] Compared to existing technologies, this embodiment achieves uniform scanning processing of diamond 600 by using a square flat-top laser pulse through the homogenization process of the homogenizing fiber 300. Furthermore, the relative position between the pulsed laser and diamond 600 can be adjusted by the scanning galvanometer 500, thereby controlling the scanning path and scanning interval of diamond 600. This invention can achieve the effect of multiple scanning processing using traditional circular Gaussian pulsed lasers, that is, multiple scanning processing can be achieved with a single scan, reducing the number of scans, greatly reducing processing time, and improving processing efficiency.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., 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 laser polishing apparatus, characterized in that, include: Laser generator, focusing and coupling unit, homogenizing fiber, spot shaping unit, and scanning galvanometer; The laser generator is used to generate pulsed laser light; The focusing coupling unit is used to focus and couple the pulsed laser, enabling the laser to be transmitted efficiently in the optical fiber. The homogenizing fiber is used to homogenize and shape the laser pulse to obtain a square-topped laser spot. The spot shaping unit is used to control the size of the square flat-top spot so that the laser is coupled into the galvanometer. The scanning galvanometer is used to control the relative motion between the pulsed laser and the diamond. By controlling the laser scanning speed and the line spacing, the distance between the light spots is equal to the diameter of the light spots, and the scanning and polishing of the diamond is completed on the preset scanning path.

2. The laser polishing apparatus as described in claim 1, characterized in that, The diamond is placed on the stage, and the scanning galvanometer is used to control the scanning speed of the pulsed laser, the scanning line spacing, and the relative position between the laser and the diamond.

3. The laser polishing apparatus as described in claim 1, characterized in that, The spot shaping unit is used to adjust the light emitted from the optical fiber into parallel light and control the spot size to achieve the optimal galvanometer entrance pupil diameter.

4. The laser polishing apparatus as described in claim 1, characterized in that, The focusing coupling unit is used to adjust the Rayleigh length and divergence angle of the pulsed laser generated by the laser generator after focusing.

5. A laser polishing method, characterized in that, The laser polishing apparatus according to any one of claims 1-4 comprises the following process: Based on the spot spacing required for the close arrangement of square flat-top light spots, determine the laser scanning speed and scanning line spacing required when setting the parameters of the scanning galvanometer, so that the spot spacing is equal to the spot diameter; A lens group is used to shape the pulsed laser to adjust the size of the spot. After the pulsed laser is adjusted into parallel light by the lens group, it is focused by the field lens to form a square flat-top spot, so that each processing area is uniformly scanned by the modulated flat-top pulsed laser. The scanning mirror controls the relative movement of the flat-top pulsed laser with the diamond, completing the scanning and processing of the diamond along a preset path.

6. The laser polishing method as described in claim 5, characterized in that, Before using a lens group to shape the pulsed laser into a flat-top pulsed laser, a focusing coupling unit is used to focus and couple the pulsed laser to obtain a pulsed laser that can be optimally coupled with the optical fiber.

7. The laser polishing method as described in claim 5, characterized in that, The homogenized optical fiber modulates the incident light using total internal reflection homogenization to generate a uniform light spot, and then focuses it through a field lens to form a square flat-top light spot for uniform processing.

8. The laser polishing method as described in claim 5, characterized in that, The relative spatial position between the focusing coupling unit and the homogenizing optical fiber is adjusted by a three-dimensional displacement stage.

9. The laser polishing method as described in claim 5, characterized in that, Adjust the size of the square flat-top light spot so that the polishing effect achieved by a single scan is greater than or equal to the polishing effect of three Gaussian light spots.

10. The laser polishing method as described in claim 5, characterized in that, By adjusting the relative position of the pulsed laser and the diamond using a scanning galvanometer, the scanning path and scanning interval of the diamond can be controlled.

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