Laser processing system for rapidly preparing large-area zero-taper microstructure

Abstract

The utility model discloses a laser processing system for rapidly preparing a large-area zero-taper microstructure, and belongs to the technical field of laser processing optical design. The laser processing system comprises a laser device, a beam expanding and collimating system, a shaping system, a translation transformation system and a focusing system which are sequentially arranged on a main shaft of a system light path, the translation transformation system comprises a first lens and a second lens, the focal length of the first lens is f1, the focal length of the second lens is f2, the distance between the first lens and the second lens is f1 + f2, and the focal length of the first lens is f1; the shaping system is located between the rear focal plane of the first lens and the first lens; the focusing system comprises a galvanometer and a field lens arranged at the emergent end of the galvanometer, and the field lens is located between the front focal plane of the second lens and the second lens. Microstructure machining is carried out through the laser machining system, the problem that the machining amplitude of a traditional rotary cutting laser machining system is too small is effectively solved, the machining efficiency is greatly improved, the taper problem existing in laser machining is solved, and the machining quality is better guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of laser processing optical design technology, and in particular to a laser processing system for rapidly preparing large-area non-tapered microstructures. Background Technology

[0002] Laser processing technology, as a mainstay in the field of materials processing, plays an indispensable role in various applications such as cutting, welding, drilling, and ablation due to its extremely high brightness, precision, and operational flexibility. This unique laser beam can concentrate high-intensity thermal energy on materials within a very short time window, thereby effectively changing the internal structure and appearance of the materials.

[0003] However, when using a Gaussian beam for processing, its focusing characteristics inevitably limit the processing effect to some extent. During the diffusion propagation process, the focused Gaussian beam gradually evolves into a conical beam, reaching its narrowest point at the focal plane, where the spot size is smallest and the energy density is highest. As it moves away from the focal plane, the beam diverges again, causing the energy distribution to become less concentrated. Therefore, when the focused beam irradiates the material surface and attempts to penetrate deeper, the laser at the edges is absorbed and reflected at the material surface, resulting in a so-called "light blocking" effect. This causes the beam energy to gradually decrease as it penetrates deeper into the material, preventing it from acting uniformly at all depths. This results in the central region being more susceptible to laser influence than the surrounding areas, leading to a conical shape in the vertical direction of the processed area. This taper problem not only damages the overall structural integrity of the material but may also negatively impact its performance.

[0004] To overcome this challenge, several innovative laser processing solutions have been developed. These include using burst pulse modes to regulate the laser beam's energy output; altering the beam's spatiotemporal distribution characteristics; combining chemical or water jet-assisted methods to optimize the laser-material interaction process; adjusting the processing path design; and precisely controlling various laser processing parameters. These strategies all help mitigate light obstruction and, to some extent, alleviate the taper problem during processing. However, these methods cannot completely eliminate the cause of taper.

[0005] Rotary cutting is a laser processing method that controls the deflection angle of the focused laser beam to address this problem. It requires the focused laser beam to form an acute angle with the processing surface. By rotating this tilted focused beam, the outer edge of the focused laser beam can be prevented from contacting the hole wall during processing, thus avoiding light obstruction and perfectly solving the processing taper problem caused by the focusing effect. Specific implementation methods include dynamic control of the relative attitude between the beam and the sample, guiding laser deflection using a rotating prism system, precisely controlling the laser path using a five-axis galvanometer, and combinations of galvanometers and 4f optical systems. However, because rotary cutting systems typically have only one focused beam and a limited scanning area, they are generally used for various micro-hole processing. To apply them to the processing of large-area materials, a point-by-point scanning method similar to a mechanical milling cutter must be adopted, resulting in extremely low processing efficiency. This is a key bottleneck that urgently needs improvement. Patent CN114888458A proposes a parallel rotary cutting processing device and method. By introducing a multi-beam generating device before the rotary cutting system, the number of focused beams can be increased, allowing for parallel processing of the sample and significantly improving processing efficiency. However, the processing area of ​​the entire optical system has not changed; it can still only be processed in a small area and cannot be applied to large-area fabrication needs. Utility Model Content

[0006] The purpose of this invention is to provide a laser processing system for rapidly preparing large-area, taper-free microstructures, addressing the existing technological status quo. This system not only effectively solves the problem of excessively small processing area in traditional rotary laser processing systems, greatly improving processing efficiency, but also overcomes the taper problem in laser processing, thus better ensuring processing quality.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A laser processing system for rapidly fabricating large-area taper-free microstructures includes a laser, a beam expansion and collimation system, a shaping system, a translation and transformation system, and a focusing system, all mounted on the main optical axis of the system.

[0009] The beam expanding and collimating system is arranged in front of the laser and is used to amplify and collimate the outgoing light from the laser.

[0010] The shaping system is arranged before the beam expanding and collimating system. The shaping system is used to shape the outgoing light from the beam expanding and collimating system into a target beam with a divergence angle and multiple light transmissions.

[0011] The translation transformation system is arranged in front of the shaping system. The translation transformation system is used to translate and transform the target beam behind it to its front. The translation transformation system includes a first lens and a second lens. The focal length of the first lens is f1, the focal length of the second lens is f2, the distance between the first lens and the second lens is f1+f2, and the shaping system is located between the back focal plane of the first lens and the first lens.

[0012] The focusing system is arranged before the translation transformation system. The focusing system includes a galvanometer and a field lens disposed at the exit end of the galvanometer. The field lens is located between the front focal plane of the second lens and the second lens. The galvanometer is used to enable its outgoing light to perform two-dimensional scanning, and the field lens is used to focus the outgoing light of the galvanometer onto the plane to be processed.

[0013] Furthermore, after the shaping system shapes the outgoing light from the beam expanding and collimating system into the target beam, the target beam has a divergence angle of at least 0.3° relative to the outgoing light from the beam expanding and collimating system.

[0014] Furthermore, the shaping system is a spatial light modulator, a DOE, or a grating.

[0015] Furthermore, the shaping system can shape the emitted light from the beam expanding and collimating system into a multifocal beam, a ring beam, or a flat-top beam.

[0016] Furthermore, the focal length of the field lens is no greater than 50mm.

[0017] Furthermore, the laser is either an ultrafast laser or a non-ultrafast laser.

[0018] Furthermore, the emitted light from the laser is a Gaussian beam.

[0019] Furthermore, the wavelength of the emitted light from the laser is in the ultraviolet, visible, or infrared band.

[0020] The beneficial effects of this utility model are as follows:

[0021] This invention provides a laser processing system for rapidly fabricating large-area, taper-free microstructures. In this system, the laser's output beam is first amplified and collimated by a beam expander and collimator, then shaped by a shaping system into a target beam with a divergence angle and multiple beams. The target beam is then converted by a translation transformation system to a focusing system. A galvanometer in the focusing system scans the output beam along a preset processing trajectory, and a field lens in the focusing system partially or completely tilts and focuses the output beam onto the plane to be processed. This allows for the rapid fabrication of large-area, taper-free microstructures on the processing plane. Using this laser processing system for microstructure fabrication not only effectively solves the problem of excessively small processing area in traditional rotary laser processing systems, greatly improving processing efficiency, but also overcomes the taper problem inherent in laser processing, better ensuring processing quality. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the optical path connection structure of a laser processing system for rapidly fabricating large-area tapered microstructures according to the present invention.

[0023] Figure 2 This is a schematic diagram of the focusing effect of the field lens on the two focal beams after being shaped by the shaping system in a laser processing system for rapid fabrication of large-area non-tapered microstructures according to this utility model (the distance between the first lens and the second lens is f1+f2, and the back focal plane of the field lens coincides with the front focal plane of the second lens).

[0024] Figure 3 This is a schematic diagram of the focusing effect of the field lens on the two focal beams after being shaped by the shaping system in a laser processing system for rapid fabrication of large-area tapered microstructures according to this utility model (the distance between the first lens and the second lens is f1+f2, and the field lens is located between the front focal plane of the second lens and the second lens).

[0025] Labeling instructions: 1. Laser, 2. Beam expanding and collimating system, 3. Shaping system, 4. First lens, 5. Second lens, 6. Galvanometer, 7. Field lens, 8. Mirror. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific examples described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0027] Please see Figure 1 As shown, a laser processing system for rapidly fabricating large-area tapered microstructures includes a laser 1, a beam expander and collimator system 2, a shaping system 3, a translation and transformation system, and a focusing system, all mounted on the main optical axis of the system.

[0028] The beam expansion and collimation system 2 is arranged in front of the laser 1. The beam expansion and collimation system 2 is used to amplify and collimate the output light of the laser 1.

[0029] Specifically, laser 1 is an ultrafast laser or a non-ultrafast laser, the emitted light of laser 1 is a Gaussian beam or other beam, and the wavelength of the emitted light of laser 1 is in the ultraviolet, visible or infrared band, depending on the processing requirements, and is not limited here.

[0030] The shaping system 3 is arranged before the beam expanding and collimating system 2. The shaping system 3 is used to shape the outgoing light from the beam expanding and collimating system 2 into a target beam with a divergence angle and multiple beams. After the shaping system 3 shapes the outgoing light from the beam expanding and collimating system 2 into a target beam, the target beam has a divergence angle of at least 0.3° relative to the outgoing light from the beam expanding and collimating system 2.

[0031] Specifically, the shaping system 3 is a spatial light modulator, a DOE (diffractive optical element), or a grating. The shaping system 3 can shape the outgoing light from the beam expanding and collimating system 2 into a multifocal beam, a ring beam, or a flat-top beam, depending on the processing requirements. No limitation is made here.

[0032] The translation transformation system is arranged in front of the shaping system 3. The translation transformation system is used to translate and transform the target beam behind it to the front of it. The translation transformation system includes a first lens 4 and a second lens 5. The focal length of the first lens 4 is f1, the focal length of the second lens 5 is f2, the distance between the first lens 4 and the second lens 5 is f1+f2, and the shaping system 3 is located between the back focal plane of the first lens 4 and the first lens 4.

[0033] The focusing system is positioned before the translation transformation system. The focusing system includes a galvanometer 6 and a field lens 7 disposed at the exit end of the galvanometer 6. The field lens 7 is located between the front focal plane of the second lens 5 and the second lens 5. The galvanometer 6 is used to achieve two-dimensional scanning of its outgoing light, and the field lens 7 is used to focus the outgoing light from the galvanometer 6 onto the plane to be processed. The focal length of the field lens 7 is no greater than 50mm.

[0034] It should be noted that the laser processing system also includes several reflectors 8, which are used for beam propagation.

[0035] According to the above design, in the laser processing system for rapid fabrication of large-area taper-free microstructures of this utility model, the emitted light of the laser 1 is first amplified and collimated by the beam expanding and collimating system 2, and then shaped by the shaping system 3 into a target beam with divergence angle and multiple beams. The target beam is converted to the focusing system by the translation transformation system. The galvanometer 6 of the focusing system makes its emitted light scan according to the preset processing trajectory. The field lens 7 of the focusing system makes its emitted light partially or completely tilted and focused onto the plane to be processed, so that large-area taper-free microstructures can be rapidly fabricated on the processing plane.

[0036] Under different conditions, the focusing effect of field lens 7 on the two focal beams shaped by shaping system 3 is as follows:

[0037] When the distance between the first lens 4 and the second lens 5 is f1 + f2, and the back focal plane of the field lens 7 coincides with the front focal plane of the second lens 5, the field lens 7 of the focusing system ensures that all outgoing light is perpendicularly focused onto the plane to be processed. See [link to focusing effect]. Figure 2When performing microstructure scanning and processing based on this beam, it is impossible to avoid the beam-blocking effect of the surface to be processed, and the taper problem cannot be eliminated;

[0038] When the distance between the first lens 4 and the second lens 5 is f1+f2, and the field lens 7 is located between the front focal plane of the second lens 5 and the second lens 5, the field lens 7 of the focusing system tilts and focuses all the outgoing light onto the plane to be processed, thus forming an off-axis tilted focused beam. See [link to focusing effect description]. Figure 3 By using this beam for microstructure scanning and processing, the beam-blocking effect of the surface to be processed can be avoided, thus eliminating the taper problem.

[0039] In summary, this laser processing system effectively solves the problem of insufficient processing area in traditional rotary laser processing systems, significantly improving processing efficiency. It also overcomes the taper issue inherent in laser processing, better ensuring processing quality. Furthermore, when the shaping system 3 shapes the output beam from the beam expanding and collimating system 2 into a multi-focal beam, parallel processing of the multi-focal beams can be achieved, further enhancing processing efficiency. When the shaping system 3 shapes the output beam from the beam expanding and collimating system 2 into a flat-top beam, the beam energy distribution can be homogenized, ensuring consistent processing results.

[0040] This utility model is not limited to the specific embodiments described above. Those skilled in the art can implement this utility model using various other specific embodiments based on the content disclosed in this utility model. Therefore, any design that adopts the design structure and concept of this utility model and makes some simple changes or modifications falls within the protection scope of this utility model.

Claims

1. A laser processing system for rapid fabrication of large area non-tapered microstructures, characterized by: The system comprises a laser arranged on a main axis of a light path of the system, a beam expansion and collimation system, a shaping system, a translation transformation system and a focusing system; The beam expansion and collimation system is arranged before the laser, and is used for amplifying and collimating the outgoing light of the laser; The shaping system is arranged before the beam expansion and collimation system, and is used for shaping the outgoing light of the beam expansion and collimation system into a target light beam with a divergence angle and a multi-beam; The translation transformation system is arranged before the shaping system, and is used for translating the target light beam behind the translation transformation system to the front of the translation transformation system, and the translation transformation system comprises a first lens and a second lens, the focal length of the first lens is f1, the focal length of the second lens is f2, the distance between the first lens and the second lens is f1+f2, and the shaping system is located between the rear focal plane of the first lens and the first lens; The focusing system is arranged before the translation transformation system, and comprises a galvanometer and a field lens arranged at the exit end of the galvanometer, and the field lens is located between the front focal plane of the second lens and the second lens, the galvanometer is used for realizing two-dimensional scanning of the outgoing light of the galvanometer, and the field lens is used for focusing the outgoing light of the galvanometer to a plane to be processed.

2. The laser processing system for quickly preparing a large-area microstructure without taper according to claim 1, characterized in that: After the shaping system shapes the outgoing light of the beam expansion and collimation system into the target light beam, the target light beam has a divergence angle of at least 0.3° relative to the outgoing light of the beam expansion and collimation system.

3. The laser processing system for quickly preparing a large-area microstructure without taper according to claim 2, characterized in that: The shaping system is a spatial light modulator or a DOE or a grating.

4. The laser processing system for quickly preparing a large-area microstructure without taper according to claim 3, characterized in that: The shaping system can shape the outgoing light of the beam expansion and collimation system into a multi-focal light beam or a ring-shaped light beam or a flat-top light beam.

5. The laser processing system for quickly preparing a large-area microstructure without taper according to claim 1, characterized in that: The focal length of the field lens is not greater than 50 mm.

6. The laser processing system for quickly preparing a large-area microstructure without taper according to claim 1, characterized in that: The laser is an ultrafast laser or a non-ultrafast laser.

7. The laser processing system for quickly preparing a large-area microstructure without taper according to claim 6, characterized in that: The outgoing light of the laser is a Gaussian light beam.

8. The laser processing system for quickly preparing a large-area microstructure without taper according to claim 7, characterized in that: The wavelength of the outgoing light of the laser is in the ultraviolet light band, the visible light band or the infrared light band.

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