Double-flat-topped light beam diamond polishing device and method based on homogenized optical fiber

Abstract

The invention discloses a double-flat-topped light beam diamond polishing device and method based on homogenized optical fibers, and relates to the technical field of semiconductor material laser processing. The light spot homogenizing unit homogenizes the pulse laser to obtain a square flat-topped light spot; the light spot shaping unit collimates the homogenized pulse laser into parallel light and adjusts the beam diameter; the beam splitting and sub-transfer unit splits the parallel light into two sub-light beams, the two sub-light beams are adjusted to be coplanar and parallel to each other, and the center-to-center distance between the two sub-light beams is adjustable; the laser processing head unit focuses the two sub-light beams on the surface of the diamond; and the three-dimensional motion platform is used for bearing the diamond and scanning and polishing the diamond. Multi-focus array parallel scanning increases the coverage area of single-time processing, the processing effect of traditional single-focus multi-time scanning can be achieved through one-time scanning, the scanning frequency is remarkably reduced, the processing time consumption is reduced, and the processing efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser processing of semiconductor materials, in particular to a double-flat-top beam diamond polishing device and method based on a homogenization optical fiber. BACKGROUND

[0002] For diamond polishing technology, single Gaussian beam laser polishing as a new polishing technology, although it solves the surface damage problem of mechanical polishing to some extent, but there are still many technical bottlenecks that are difficult to overcome. Single Gaussian beam laser polishing adopts single focus single scanning processing mode, and the single processing coverage area is very small. In order to achieve the preset polishing effect, multiple repeated scanning is often needed, which leads to long processing time and low processing efficiency, and it is difficult to meet the needs of large-scale industrial mass production.

[0003] In order to solve the problem of low efficiency of single beam laser polishing, some researches improve the processing efficiency by multi-beam parallel scanning. However, most of such devices use complex light path splitting and multi-path synthesis modules to realize multi-beam output, which not only leads to large device structure and low integration, but also increases the difficulty of light path debugging and equipment maintenance, and increases the manufacturing cost and operation and maintenance cost of the equipment. In addition, the beams output by the existing multi-beam device are mostly Gaussian beams, which have not realized energy homogenization shaping, and the energy consistency between the multi-beams is poor and the spacing is uncontrollable, which easily causes the problem of excessive energy in the superposition area and insufficient energy in the non-superposition area, thereby aggravating the unevenness of the polished surface and failing to achieve high-quality polishing.

[0004] In addition, the existing homogenization optical fiber applied to diamond polishing is limited to single flat-top beam output, and has not combined the design idea of multi-beam parallel processing, and still has the defects of small single scanning coverage area and low processing efficiency. While a few attempts to combine homogenization optical fiber and multi-beam require multiple objectives to be focused, which not only increases the complexity of the device, but also makes it difficult to ensure the spatial consistency of the multi-beam focal points, further affecting the polishing precision and stability. SUMMARY

[0005] In order to solve the above problems, the present application provides a double-flat-top beam diamond polishing device and method based on a homogenization optical fiber, which increases the single processing coverage area by multi-focus array parallel scanning. After one scanning, the processing effect of traditional single focus multiple scanning can be achieved, the scanning times are significantly reduced, the processing time is reduced, and the processing efficiency is improved.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme: In a first aspect, the present application provides a double-flat-top beam diamond polishing device based on a homogenization optical fiber, comprising: a laser generator for generating pulsed laser; A spot homogenization unit includes a homogenization fiber, which is used to homogenize the pulsed laser to obtain a square flat-top spot. The spot shaping unit is used to collimate the homogenized pulsed laser into parallel light and adjust the spot size. The beam splitting and sub-transfer unit includes a beam splitter and two symmetrical sub-transfer optical paths. The beam splitter is used to split the parallel light into two sub-beams on the parallel light path. The two symmetrical sub-transfer optical paths are used to adjust the two beams to be in the same plane and parallel to each other, and to make the center distance between the two beams adjustable. A laser processing head unit is used to focus two beams onto the diamond surface. The three-dimensional motion platform is used to carry the diamond, control the relative motion between the diamond and the multi-focal sub-beam, and adjust the relative position between the diamond and the laser processing head unit. According to the set scanning speed and scanning line spacing, it completes the scanning and polishing of the diamond on the preset scanning path.

[0007] As an alternative implementation, the spot homogenization unit further includes a focusing lens for coupling pulsed laser light into the homogenization fiber.

[0008] As an alternative implementation, the homogenizing fiber, when homogenizing the pulsed laser, obtains a square flat-topped light spot by adjusting the incident angle and divergence angle of the pulsed laser.

[0009] As an alternative implementation, the spot shaping unit includes a lens group, which modulates the homogenized pulsed laser by adjusting the lens spacing of the lens group.

[0010] As an alternative implementation, the beam splitter is used to split parallel light into two beams of uniform energy.

[0011] As an alternative implementation, the two symmetrical sub-transfer optical paths are structurally symmetrical folded optical paths, and each folded optical path includes at least two mirrors or prisms for achieving directional correction and lateral displacement of the two sub-beams.

[0012] As an alternative implementation, by adjusting the spatial position of the sub-transfer optical path, the positional relationship between the sub-beams is made to achieve the optimal numerical aperture of the laser processing head unit, so that the two sub-beams are incident into the laser processing head unit.

[0013] As an alternative implementation, the center distance between the two sub-beams can be adjusted by adjusting the lateral displacement, and by setting the center distance between the two sub-beams, two square flat-top light spots can form parallel processing zones in the direction perpendicular to the scanning direction.

[0014] As an alternative implementation, the laser processing head unit includes an objective lens, through which two beams are focused to form two square flat-topped light spots with adjustable center spacing on the diamond surface.

[0015] In a second aspect, the present invention provides a dual-flat-top beam diamond polishing method based on homogenized optical fiber, utilizing the dual-flat-top beam diamond polishing apparatus based on homogenized optical fiber of the first aspect, comprising: Based on the required spot spacing for arranging square flat-top light spots, determine the scan line spacing and scan speed; After the pulsed laser is coupled into the homogenizing fiber using a focusing lens, the pulsed laser is homogenized by the homogenizing fiber to obtain a square flat-topped spot; After the homogenized pulsed laser is collimated into parallel light by the spot shaping unit, it is split into two sub-beams with the same energy by the beam splitting and sub-transfer unit, so that each processing area is scanned by the multi-focus pulsed laser formed by the split beam. The relative motion between the diamond and the multi-focus pulsed laser is controlled by a three-dimensional motion platform, and the relative position between the diamond and the laser processing head unit is adjusted. According to the set scanning speed and scanning line spacing, the diamond is scanned and polished on the preset scanning path.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes a dual-flat-top beam diamond polishing device and method based on homogenized optical fiber. It can simultaneously generate a multifocal array with uniform energy and controllable spacing using a single objective lens, eliminating the need for complex optical path splitting and multi-path combining modules. This results in a compact, highly integrated device that is easy to debug and maintain, effectively reducing manufacturing costs and operational complexity. Furthermore, the parallel scanning of the multifocal array significantly increases the processing area in a single pass. A single scan can achieve the processing effect that traditional single-focal Gaussian pulse laser beams require multiple scans to achieve, thus significantly reducing the number of scans, greatly decreasing processing time, and improving processing efficiency.

[0017] 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

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1This is a schematic diagram of a dual-flat-top beam diamond polishing device based on homogenized optical fiber provided in Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of the processing path for a circular Gaussian spot scanning process. Figure 3 This is a schematic diagram of the multi-focus square flat-top spot scanning processing path provided in Embodiment 1 of the present invention.

[0020] Among them, 100 is the laser generator; 200 is the spot homogenization unit; 300 is the spot shaping unit; 400 is the beam splitting and sub-transfer unit; 500 is the laser processing head unit; 600 is the diamond; and 700 is the three-dimensional motion platform. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] 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.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that the terms “comprising” and “including”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0025] Example 1 This embodiment proposes a dual-flat-top beam diamond polishing device based on homogenized optical fiber. The device uses homogenized optical fiber to homogenize and shape the pulsed laser. A lens group obtains a controllable square flat-top beam on the focal plane. A beam splitting and sub-transfer unit 400 divides the laser beam into two square flat-top beams with equal energy, uniform distribution, and clear edges. A single objective lens generates a spatially uniform multi-focal array, enabling synchronous parallel polishing of multiple regions on the diamond 600 surface. By controlling the laser scanning speed and scanning line spacing, the distance between beam spots is made equal to the beam spot diameter, achieving uniform energy and high-efficiency polishing of the diamond 600. Under a single laser source, a single scan achieves the processing effect of multiple scans required by traditional single-focal methods, thus greatly reducing the total processing time.

[0026] like Figure 1 As shown, it includes a laser generator 100, a spot homogenization unit 200, a spot shaping unit 300, a beam splitting and sub-transfer unit 400, a laser processing head unit 500, a diamond 600, and a three-dimensional motion platform 700.

[0027] Specifically: The laser generator 100 is used to generate pulsed lasers with a set wavelength and repetition frequency.

[0028] The beam homogenization unit 200 includes a focusing lens and a homogenizing fiber. The focusing lens is used to couple the pulsed laser into the homogenizing fiber, and the homogenizing fiber is used to homogenize the pulsed laser. By adjusting the incident angle and divergence angle of the focused pulsed laser, a square flat-top beam is obtained.

[0029] The spot shaping unit 300 includes a lens group, which is used to collimate the pulsed laser homogenized by the spot homogenization unit 200 into parallel light and adjust the spot size so that the parallel light is focused by the objective lens to form a square flat-topped spot on the surface of the diamond 600.

[0030] The beam splitting and sub-transfer unit 400 includes a beam splitter and two symmetrical sub-transfer optical paths. The beam splitter is used to split the parallel light into two sub-beams on the parallel light path. The two symmetrical sub-transfer optical paths are used to adjust the two beams to be in the same plane and parallel to each other, and to make the center distance between the two beams adjustable.

[0031] The laser processing head unit 500 includes an objective lens, which is used to focus two beams onto the surface of diamond 600 respectively. After being focused by the objective lens, two square flat-topped light spots with adjustable center spacing are formed on the surface of diamond 600.

[0032] The three-dimensional motion platform 700 is used to carry the diamond 600, control the relative motion between the diamond 600 and the multi-focal sub-beam, and adjust the relative position between the diamond 600 and the laser processing head unit 500. According to the set scanning speed and scanning line spacing, the diamond 600 is scanned and polished on the preset scanning path.

[0033] In this embodiment, the purpose of focusing and coupling with the focusing lens is to efficiently and distortion-free couple the pulsed laser into the homogenizing fiber, laying the foundation for subsequent spot homogenization and avoiding spot distortion and excessive energy loss due to coupling deviation.

[0034] First, fix the focusing lens on the optical adjustment frame and adjust the height and horizontal position of the focusing lens to make the optical axis of the pulsed laser coincide with the optical axis of the focusing lens, so as to avoid the focus spot shift caused by the eccentricity. Then, the incident end of the homogenizing fiber is fixed to the exit end of the focusing lens. By adjusting the position of the homogenizing fiber, the focal point of the focusing lens is made to fall on the center of the incident end face of the homogenizing fiber. At this time, the output power of the fiber is measured by a power meter to obtain the initial coupling efficiency. Furthermore, by fine-tuning the relative positions of the focusing lens and the homogenizing fiber, the optical axis deviation is corrected, coupling loss is reduced, coupling efficiency is improved, and the laser is ensured to be uniformly incident on the fiber core. Using the initial distance between the homogenizing fiber and the focusing lens as a reference, fine-tuning is performed by ±0.1mm each time, and the corresponding fiber output power is measured and the coupling efficiency is recorded until the coupling efficiency reaches the set maximum value (e.g., ≥90%). This distance is the optimal coupling distance. Maintaining the optimal coupling distance, the horizontal and vertical positions of the fiber's incident end are fine-tuned (±20μm each time), while simultaneously observing the power meter reading to ensure the coupling efficiency remains stable at its maximum value, avoiding uneven laser incident due to fiber end-face eccentricity.

[0035] After the focusing lens couples the pulsed laser into the homogenizing fiber, the homogenizing fiber homogenizes the pulsed laser. By adjusting the incident angle and divergence angle of the focused pulsed laser, a square flat-topped light spot is obtained.

[0036] Angle of incidence The angle between the laser optical axis and the fiber optical axis determines the number of total internal reflections and the path of the pulsed laser within the fiber. Adjusting... The outline of the emitted light spot from the optical fiber gradually approaches a square shape (matching the square exit end of the fiber). The incident angle constraint formula (to avoid laser leakage) is: ; This is the maximum receiving divergence angle of the optical fiber. This is the laser divergence angle after focusing; if Beyond this range, the laser will break the total internal reflection condition of the optical fiber and leak from the cladding, resulting in beam distortion and increased energy loss.

[0037] Laser divergence angle after focusing (Unit: rad) Determines the energy distribution of the pulsed laser inside the optical fiber. An excessively large divergence angle can lead to energy concentration at the fiber edge (overly bright spot edge), while an excessively small divergence angle can lead to high energy at the spot center (inability to form a flat top).

[0038] The formula for adjusting the divergence angle is: ; in, The diameter of the focused spot (μm) is the focal length. The optimal coupling distance (mm) can be achieved by fine-tuning the focal length f of the focusing lens (by changing to a lens with a different focal length) or the coupling distance. (Fine adjustment ±0.05mm), Adjustment Size.

[0039] In this embodiment, the lens group includes a collimating lens and a zoom lens arranged sequentially along the optical path. First, the pulsed laser emitted from the homogenizing fiber, which has been optimized into a square flat-top spot, is collimated into parallel light. Then, the size of the parallel light spot is changed by adjusting the spacing of the lens group to ensure that the parallel light, after being focused by the subsequent objective lens, forms a square flat-top spot of the required size on the diamond 600 surface.

[0040] Specifically: The output light (divergence angle) from the homogenized fiber Incident on the collimating lens (focal length) When the output end face of the optical fiber is located at the object-side focal point of the collimating lens, the output light is converted into parallel light, and the initial spot diameter of the parallel light is... Determined by the fiber core diameter and divergence angle: ; in, The initial diameter (mm) of the parallel light spot after collimation. The focal length (mm) of the collimating lens. The optimized laser half-divergence angle (rad).

[0041] Spot size adjustment (zoom lens adjustment): Zoom lens (focal length) The distance between the collimating lens and the collimating lens is ,adjust Change the magnification of the lens group This, in turn, changes the diameter of the emitted parallel light spot. Ultimately, the size of the light spot on the surface of the diamond 600 is controlled. ; Among them, the magnification of the lens group Diameter of parallel light spot after reshaping The size of the light spot on the surface of the diamond 600 (focused through the objective lens). ; Adjustment range is To avoid aberrations in the lens group; The focal length of the objective lens is (mm). This is the total focal length of the lens group. ; The target side length (mm) of the square flat-topped spot on the surface of the diamond 600 needs to be set according to actual requirements.

[0042] Adjust the distance between the collimating lens and the output end of the homogenizing fiber. Use a parallel light detector to check the light emitted from the lens assembly to ensure that the emitted light is parallel (parallelism deviation is within the preset range). Record the diameter of the light spot at this time. (Can be measured using a spot analyzer).

[0043] Based on the target spot length on the diamond 600 surface, substitute it into the formula to calculate the required magnification of the lens group and the zoom lens spacing; using the required zoom lens spacing as a reference, adjust the spacing between the collimating lens and the zoom lens. Meanwhile, observe the readings of the diamond 600 surface spot analyzer until the spot edge length is close to the target spot edge length and the deviation value is within the preset range.

[0044] In summary, this embodiment modulates the homogenized pulsed laser using different lens spacings to generate parallel light, which is then focused onto the surface of the diamond 600 by the laser processing head unit 500 for uniform processing.

[0045] In this embodiment, the energy distribution of the sub-beams can be changed by the beam splitting and sub-transfer unit 400. The beam splitter is used to split the parallel light into two sub-beams with uniform energy (1:1). The two symmetrical sub-transfer optical paths are structurally symmetrical folded optical paths, and each folded optical path includes at least two mirrors or prisms to achieve directional correction and lateral displacement of the two sub-beams.

[0046] As an alternative implementation, in the beam splitting and sub-transfer unit 400, the energy ratio of the two sub-beams is controlled by a half-wave plate, and the pulsed laser is split into two sub-beams with different polarization states by a polarizing beam splitter, which is an optical element capable of splitting a beam.

[0047] Here is a basic method to achieve this goal: First, prepare a Gaussian beam, which can be a high-quality beam from laser generator 100; then, it is modulated into parallel light by a lens group. The polarization beam splitter is usually made of two 45° isosceles right-angle prisms with their bottom edges glued together. The angle between the sub-beams can be adjusted by adjusting the incident angle of the incident laser, and the polarization state distribution of the main pulse laser can be adjusted by rotating the half-wave plate, thereby adjusting the energy distribution of the two sub-beams.

[0048] The angle between the sub-beams also depends on the angle between the sub-transfer optical path and the sub-beams. Adjusting the spatial position of the sub-transfer optical path allows the positional relationship between the sub-beams to achieve the optimal numerical aperture of the laser processing head unit 500, so that the two sub-beams are incident into the laser processing head unit 500. The center distance between the two sub-beams can be adjusted by adjusting the lateral displacement, and by setting the center distance between the two sub-beams, the two square flat-topped light spots form parallel processing zones in the direction perpendicular to the scanning direction.

[0049] Finally, the laser processing head unit 500 is placed on the Z-axis of the three-dimensional motion platform 700, and the laser spot is controlled to be located on the surface of the diamond 600 by adjusting the height of the Z-axis.

[0050] As an alternative implementation, the square flat-top parallel light emitted from the spot shaping unit 300 is split into two sub-beams by a polarizing beam splitter. The energy ratio of the two sub-beams is adjusted by a half-wave plate, and the direction of the sub-beams is corrected by two symmetrical folded optical paths to achieve lateral displacement adjustment. Finally, the two sub-beams are made to be on the same plane and parallel to each other, and the center distance and energy ratio are adapted to the optimal numerical aperture of the laser processing head unit 500. This ensures that the two sub-beams are superimposed to form a square flat-top spot on the diamond 600 surface that meets the requirements.

[0051] Among them, the two sub-transfer optical paths are symmetrical folded optical paths. Each optical path contains at least two mirrors (or prisms). By adjusting the angle of the mirrors (or prisms), the direction of the sub-beams can be corrected so that the two sub-beams remain in the same plane and parallel to each other. At the same time, by adjusting the spatial position of the folded optical path laterally, the lateral displacement of the two sub-beams can be changed, thereby realizing the adjustable center distance between the two sub-beams. Meanwhile, the two square flat-top light spots form parallel processing zones in the direction perpendicular to the scanning direction.

[0052] As an alternative implementation method, the adjustment process is as follows: Beam splitting angle and sub-beam direction adjustment: Fine-tune the incident angle of the polarized beam splitter, while observing the spot analyzer, and adjust the angle of the reflectors (or prisms) of the two symmetrical sub-transfer optical paths until the two sub-beams are on the same plane, parallel to each other, and the sub-beams are parallel to the optical axis of the laser processing head unit 500.

[0053] Adjustment of the energy ratio of sub - beams: Set the target energy ratio of the two sub - beams (such as 1:1) according to the processing requirements. Start rotating the half - wave plate from the initial 0°, slowly (±1° each time), and simultaneously measure the output power of the two sub - beams with a power meter 、 , calculate the energy ratio , until the energy ratio reaches the target value.

[0054] Adjustment of the center distance between sub - beams: Set the target center distance of the two sub - beams according to the optimal numerical aperture of the laser processing head unit 500 (unit: mm), adjust the lateral displacement, and simultaneously measure the center distance of the two sub - beams through a spot analyzer , until .

[0055] It should be noted that the above process only basically describes how to split the laser using the beam splitting and sub - transfer unit 400. The specific implementation methods and adjustment steps may vary depending on the actual application and equipment. In addition, without changing the hardware equipment, this invention can meet various processing requirements, improve the processing freedom, and achieve efficient diamond 600 polishing.

[0056] In the traditional laser polishing method, to focus the circular Gaussian spot on the surface of diamond 600, the pulsed laser is scanned on diamond 600 according to a preset scanning path and scanning speed. After the scanning is completed, multiple scans are performed with different scanning speeds and scanning line spacings to finally obtain a reasonable spot overlap rate. As Figure 2 shown, the scanning path is in the shape of a "ji".

[0057] In this embodiment, a diamond polishing device based on a homogenizing optical fiber with a double - flat - top beam is proposed to scan - process diamond 600. As Figure 3 shown, the specific operation process is as follows: The laser generator 100 is used to generate pulsed laser with a set wavelength and repetition frequency; the spot homogenizing unit 200 is used to homogenize the pulsed laser generated by the laser generator 100, adjust the incident angle and divergence angle of the pulsed laser after focusing, and obtain a square flat - top spot; the spot shaping unit 300 is used to modulate the pulsed laser homogenized by the spot homogenizing unit 200 into parallel light and adjust the spot size; the beam splitting and sub - transfer unit 400 is used to split the parallel light into two sub - beams with uniform energy; the laser processing head unit 500 is used to focus the two sub - beams on the surface of diamond 600 respectively; by controlling the three - dimensional motion platform 700, diamond 600 is moved in a preset direction, so that according to the set scanning speed and scanning line spacing, the scanning and polishing of diamond 600 are completed on the preset scanning path. Through the precise guidance of the square flat - top spot pulsed laser in space position, single - time uniform scanning and polishing are achieved.

[0058] In summary, the aforementioned dual-flat-top beam diamond polishing device based on homogenized optical fiber, compared with the traditional Gaussian spot scanning processing method, only requires one scan of the diamond 600, thus improving the number of scans and significantly shortening the processing time. In addition, reducing the number of scans to a single scan also improves the stability of the processing. Furthermore, the energy of the spot can be controlled as needed to achieve controlled and selective scanning processing, which greatly improves the processing efficiency and solves the problems of low processing efficiency, long processing time, and poor quality in existing processes.

[0059] Example 2 Based on the aforementioned dual-flat-top beam diamond polishing device based on homogenized optical fiber, this embodiment provides a dual-flat-top beam diamond polishing method based on homogenized optical fiber, comprising: Based on the spot spacing required for the close arrangement of square flat-top light spots, the laser scanning line spacing and scanning speed required for parameter setting of the three-dimensional motion platform 700 are determined. After the pulsed laser is coupled into the homogenizing fiber using a focusing lens, the pulsed laser is homogenized by the homogenizing fiber to obtain a square flat-topped spot; A lens group is used to shape the homogenized pulsed laser and adjust the spot size. After the pulsed laser is collimated into parallel light by the lens group, it is split into two sub-beams with the same energy by the beam splitting and sub-transfer unit 400, so that each processing area is scanned by the multi-focus pulsed laser formed by the split beam. The relative motion between the diamond 600 and the multi-focus pulsed laser is controlled by the three-dimensional motion platform 700, and the relative position between the diamond 600 and the laser processing head unit 500 is adjusted. According to the set scanning speed and scanning line spacing, the diamond 600 is scanned and polished on the preset scanning path.

[0060] In this embodiment, before homogenizing the pulsed laser, a focusing lens is used to focus and couple the pulsed laser to improve the degree of homogenization.

[0061] In this embodiment, the spot shaping unit 300 modulates the homogenized pulsed laser with different lens spacings to generate parallel light, which is then focused onto the surface of the diamond 600 by the laser processing head unit 500 for uniform processing.

[0062] In this embodiment, the center distance between the two sub-beams is set by adjusting the lateral displacement before polishing, so that the two square flat-top beams form parallel processing bands in the direction perpendicular to the scanning direction.

[0063] In this embodiment, by adjusting the spatial position between the beam splitter and the sub-transfer optical path of the sub-transfer unit 400, two sub-beams are incident into the laser processing head unit 500.

[0064] In this embodiment, the homogenizing fiber uses total internal reflection technology to homogenize the energy of the incident light, generating a pulsed laser with a square flat-top spot. Then, the spot size is modulated by adjusting the spacing between the lens groups, and then the beam is split by the beam splitting and sub-transfer unit 400. The processing amount of a single multi-focus scan is equivalent to the effect that a traditional single-focus Gaussian spot needs to scan three or more times, resulting in an order-of-magnitude improvement in processing efficiency.

[0065] Therefore, this embodiment achieves uniform scanning processing of diamond 600 by multi-focus flat-top pulse laser through homogenization processing of the homogenizing fiber and beam splitting by the beam splitting and sub-transfer unit 400. Furthermore, by adjusting the relative position of diamond 600 and multi-focus pulse laser through the three-dimensional motion platform 700, the scanning path and scanning interval of diamond 600 can be controlled. A single scan can achieve the effect of multiple scans by traditional circular Gaussian pulse laser, reducing the number of scans, reducing processing time, and improving processing efficiency.

[0066] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A dual-flat-top beam diamond polishing device based on homogenized optical fiber, characterized in that, include: A laser generator is used to produce pulsed laser light. A spot homogenization unit includes a homogenization fiber, which is used to homogenize the pulsed laser to obtain a square flat-top spot. The spot shaping unit is used to collimate the homogenized pulsed laser into parallel light and adjust the spot size. The beam splitting and sub-transfer unit includes a beam splitter and two symmetrical sub-transfer optical paths. The beam splitter is used to split the parallel light into two sub-beams on the parallel light path. The two symmetrical sub-transfer optical paths are used to adjust the two beams to be in the same plane and parallel to each other, and to make the center distance between the two beams adjustable. A laser processing head unit is used to focus two beams onto the diamond surface. The three-dimensional motion platform is used to carry the diamond, control the relative motion between the diamond and the multi-focal sub-beam, and adjust the relative position between the diamond and the laser processing head unit. According to the set scanning speed and scanning line spacing, it completes the scanning and polishing of the diamond on the preset scanning path.

2. The dual-flat-top beam diamond polishing device based on homogenized optical fiber as described in claim 1, characterized in that, The spot homogenization unit also includes a focusing lens, which is used to couple the pulsed laser into the homogenization fiber.

3. The dual-flat-top beam diamond polishing device based on homogenized optical fiber as described in claim 1, characterized in that, When homogenizing a pulsed laser, the homogenizing fiber adjusts the incident angle and divergence angle of the pulsed laser to obtain a square flat-topped light spot.

4. The dual-flat-top beam diamond polishing device based on homogenized optical fiber as described in claim 1, characterized in that, The spot shaping unit includes a lens group, which modulates the homogenized pulsed laser by adjusting the lens spacing of the lens group.

5. The dual-flat-top beam diamond polishing device based on homogenized optical fiber as described in claim 1, characterized in that, The beam splitter is used to split parallel light into two beams with uniform energy.

6. The dual-flat-top beam diamond polishing device based on homogenized optical fiber as described in claim 1, characterized in that, The two symmetrical sub-transfer optical paths are structurally symmetrical folded optical paths, and each folded optical path includes at least two mirrors or prisms to achieve directional correction and lateral displacement of the two sub-beams.

7. The dual-flat-top beam diamond polishing device based on homogenized optical fiber as described in claim 6, characterized in that, By adjusting the spatial position of the sub-transfer optical path, the positional relationship between the sub-beams is made to achieve the optimal numerical aperture of the laser processing head unit, so that the two sub-beams are incident on the laser processing head unit.

8. The dual-flat-top beam diamond polishing device based on homogenized optical fiber as described in claim 6, characterized in that, The center distance between the two sub-beams can be adjusted by adjusting the lateral displacement, and by setting the center distance between the two sub-beams, two square flat-top light spots can form parallel processing zones in the direction perpendicular to the scanning direction.

9. The dual-flat-top beam diamond polishing device based on homogenized optical fiber as described in claim 1, characterized in that, The laser processing head unit includes an objective lens. After two beams are focused by the same objective lens, they form two square flat-topped light spots with an adjustable center-to-center distance on the diamond surface.

10. A dual-flat-top beam diamond polishing method based on homogenized optical fiber, characterized in that, The dual-flat-top beam diamond polishing apparatus based on homogenized optical fiber as described in any one of claims 1-9 comprises: Based on the required spot spacing for arranging square flat-top light spots, determine the scan line spacing and scan speed; After the pulsed laser is coupled into the homogenizing fiber using a focusing lens, the pulsed laser is homogenized by the homogenizing fiber to obtain a square flat-topped spot; After the homogenized pulsed laser is collimated into parallel light by the spot shaping unit, it is split into two sub-beams with the same energy by the beam splitting and sub-transfer unit, so that each processing area is scanned by the multi-focus pulsed laser formed by the split beam. The relative motion between the diamond and the multi-focus pulsed laser is controlled by a three-dimensional motion platform, and the relative position between the diamond and the laser processing head unit is adjusted. According to the set scanning speed and scanning line spacing, the diamond is scanned and polished on the preset scanning path.

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