Equally-spaced laser beam splitting device

Abstract

The invention discloses an equidistant laser beam splitting device which comprises an annular track, the annular track is composed of an inner track and an outer track which are located on the same plane and concentrically arranged, a rotating mirror module is located at the center of the annular track, and a plurality of beam splitting optical path modules are located on the annular track. The projection distances of the plurality of light splitting light path modules in the Y-axis direction of the annular track are consistent; the laser emits a laser beam, the laser beam is collimated by the collimator and then enters the rotating mirror module, the rotating mirror module can rotate by 360 degrees around the center of an optical axis, the laser beam is emitted by the rotating mirror module, and the emitted laser beam uniformly irradiates in each light splitting optical path module while rotating; the light splitting light path module shapes and collimates the laser beams and then gathers the laser beams to the surface of a processing sample located on the moving plane. The device comprises a collimation module, a rotating mirror beam splitting module, a shaping module and a focusing module, beam splitting and focusing of laser beams are achieved, the device is used for high-precision laser scribing machining, and the precision and stability of laser etching are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser processing, and particularly to a laser beam splitting device with equal spacing. Background Art

[0002] The laser scribing process involves multiple parameter settings, thus posing high requirements for the efficiency, precision, and flexibility of laser processing equipment and its core optical path system. Currently, common laser processing equipment is mainly divided into two types: single-path laser equipment and multi-path laser equipment. Single-path laser equipment relies on a single laser and a simple optical path design. Although it has a simple structure and low cost, it is difficult to meet the requirements of processing and detection, resulting in low processing efficiency. Currently, parallel processing can be achieved by splitting the laser beam output from a single path, thereby improving the processing efficiency.

[0003] Laser beam splitting technology can split a laser beam into multiple sub-beams, enabling the synchronous progress of multiple workstations or multiple processing processes. Due to its high efficiency, high precision, and flexibility, laser beam splitting technology is widely used in multiple fields, especially in industries with high requirements for processing precision and efficiency. It is widely used in fields such as electronics, automotive, aerospace, medical devices, precision instruments, 3D printing, packaging industry, and energy and environmental protection, and is particularly suitable for high-precision and high-efficiency production requirements such as multi-hole processing, precision drilling, laser scribing, laser cutting, and surface treatment. Laser beam splitting methods mainly include technologies such as using optical beam splitters, fiber optic beam splitters, microlens arrays, polarization beam splitters, spatial light modulators (SLMs), and reflective beam splitters. Optical beam splitters split a laser beam into multiple sub-beams through reflection or transmission; fiber optic beam splitters distribute laser energy to different optical fibers; microlens arrays focus into multiple beams through multiple small lenses; polarization beam splitters split a beam using the polarization state; spatial light modulators achieve beam splitting by dynamically adjusting the phase and intensity of the beam; and reflective beam splitters achieve beam splitting through reflections at different angles.

[0004] In the scribing processing technology, traditional mechanical scribing and mask etching methods are prone to material waste and uneven interlayer loss, while laser etching technology is considered the key to improving the utilization rate of the effective area. For example, in the preparation process of solar cells, multiple laser etching processes are required, including four processes: P1 - P3 laser scribing and P4 edge cleaning. These processes form separate modules through multiple etching steps and then are connected in series to form a component, ensuring the circuit structure and performance of the battery. Ultrafast laser etching technology has the characteristics of non-thermal processing and fine ablation, which can minimize damage to perovskite batteries. For laser etching technology, parallel etching with multiple beams can significantly improve the etching efficiency. At the same time and the same etching rate, the etching efficiency of N beams is N times higher than that of a single beam. The multiple beams split by beam splitting are required to have equal intervals, equal energy, and consistent focused spots.

[0005] The patent with the publication number CN116117332A discloses a "downward-emitting laser optical path system and a solar cell scribing machine", which uses a polarization beam splitter to achieve 12-beam splitting, and this device is used in solar scribing equipment to improve scribing efficiency. The patent with the publication number CN116160134A discloses a "multi-focus laser assembly, laser processing device and method", which uses a diffractive optical element for beam splitting, and then adjusts the divergence angles of each beam to achieve multi-focus processing. The patent with the publication number CN115156698A discloses a "laser beam splitting processing device", which uses a diffraction beam splitter to achieve multi-beam splitting.

[0006] When using the mechanical beam splitting method for multi-beam parallel etching, a large number of devices are used, the mechanical structure of the equipment is complex and the cost is high. When using mechanical beam splitting, a polarization beam splitter and a half-wave plate are used to adjust the energy of each laser beam. The polarization beam splitter depends on the polarization state of the incident light. If the polarization direction of the beam is inconsistent with the design direction of the beam splitter, the splitting efficiency will be greatly reduced. In addition, the polarization beam splitter may cause polarization loss, resulting in a change in the polarization state of some beams, affecting subsequent optical operations. Its performance is usually targeted at a specific wavelength range and cannot effectively process wide-wavelength optical signals, limiting its applicability in some applications. When using a diffractive optical element for beam splitting for multi-beam parallel etching, there are problems such as uneven spot intensity distribution, only being able to process a single repeating structure, and limited processing accuracy for the multi-beams split by the diffractive optical element. At the same time, diffractive optical elements require precise micro-structure design and manufacturing, usually using techniques such as photolithography and electron beam etching, which have high requirements for equipment and high costs; when using a spatial light modulator for beam splitting, due to the small damage threshold of the spatial light modulator, the laser can easily damage the spatial light modulator. The disadvantages of fiber optic beam splitters include power loss, degradation of beam quality, and temperature sensitivity. Due to the insertion loss introduced by the beam splitter, the power of each output channel will decrease, affecting the processing efficiency and quality, and the loss in multi-beam splitting is relatively large (1×8, the splitting loss is about 9 dB). Since the damage threshold of fiber optic beam splitters is relatively low, it is difficult to achieve beam splitting of high-power lasers. At the same time, the beam splitter may cause beam divergence or shape change, reducing the processing accuracy. In addition, fiber optic beam splitters are sensitive to temperature changes, and the thermal effect may cause performance degradation, limiting their application in high-power and high-precision processing. The stability of fiber optic connections and maintenance requirements also increase the complexity of the system. Summary of the Invention

[0007] In order to solve the problems existing in the above-mentioned background technology, the present invention provides an equidistant laser beam splitting device, which includes a collimation, rotating mirror beam splitting, shaping and focusing module, realizes the beam splitting and focusing of laser beams, and is used for high-precision laser scribing processing, greatly improving the accuracy and stability of laser etching.

[0008] To achieve the above object, the present invention adopts the following technical solutions: The present invention provides an equally-spaced laser beam splitting device, including a laser, a collimator, a rotating mirror module, an annular track, a plurality of beam splitting optical path modules, and a moving platform; The annular track is composed of an inner track and an outer track which are concentrically arranged in the same plane. The rotating mirror module is located at the central position of the annular track. A plurality of beam splitting optical path modules are located on the annular track, and the projection spacings of the plurality of beam splitting optical path modules in the Y-axis direction of the annular track are the same, ensuring that the laser scribing spacings are the same. Specifically in application, the number and installation positions of the beam splitting optical path modules can be reasonably arranged according to the number of beam splittings and the focal spacings. The pulse signals received by each beam splitting optical path module depend on its line width on the annular track. As long as the line widths are the same, it can be ensured that each beam splitting optical path module uniformly receives pulsed laser, ensuring the energy consistency of each focused light spot; The laser is a high-repetition-rate pulsed laser or a continuous laser. The laser emits a laser beam, which enters the rotating mirror module after being collimated by the collimator. The optical axis center inside the rotating mirror module is perpendicular to the plane of the annular track. The rotating mirror module can rotate 360° around the optical axis center. The emitted laser beam is emitted from the rotating mirror module, and the emitted laser beam uniformly irradiates each beam splitting optical path module while rotating, realizing the beam splitting; The beam splitting optical path module shapes and collimates the laser beam and then focuses it on the surface of the processing sample located on the moving plane. The processing sample is fixedly placed on the surface of the moving platform, and the surface of the processing sample is laser scribed by the movement of the moving plane.

[0009] Further, the beam splitting optical path module includes a beam splitting lens barrel, a first reflector, a small hole aperture, a first lens, and a second lens; the first reflector, the small hole aperture, the first lens, and the second lens are coaxially arranged and installed in the beam splitting lens barrel from top to bottom in sequence. The first reflector is inclined at 45°, changing the horizontally transmitted laser beam emitted from the rotating mirror module into a vertically transmitted laser beam. The vertically transmitted laser beam passes through the through hole of the small hole aperture for shaping, and then is collimated by the first lens and enters the second lens for focusing.

[0010] The specific working principle of the beam splitting optical path module is as follows: The horizontally transmitted split laser beam is changed into a vertically transmitted split laser beam by the first reflector. Since the spot size and spot position of the non-collimated incident light will change after focusing, a small hole aperture is arranged below the first reflector to limit the imaging of incident light at different incident angles. Below the small hole aperture is the first lens, which collimates the split laser beam into a collimated beam. The collimated beam is focused on the surface of the processing sample by the second lens below, and scribing on the surface of the processing sample is realized through the movement of the moving platform.

[0011] Furthermore, the diameter of the light passing hole of the small aperture diaphragm is 1 mm to 3 mm, which can ensure that the focused spot is less than 10 μm.

[0012] In the present invention, the small aperture diaphragm is used to limit the incident at a deflection angle during the rotation of the light beam. The size of the focused light beam can be controlled by changing the size of the light passing hole of the small aperture diaphragm. The smaller the diameter of the light passing hole of the small aperture diaphragm, the smaller the focused spot and the higher the scribing accuracy. The diameter size of the light passing hole of the small aperture diaphragm determines the offset of the light beam in the beam splitting optical path and also determines the size of the focused spot. The larger the diameter of the light passing hole, the greater the offset of the diaphragm and the larger the focused spot. The zemax simulation verification shows that controlling the diameter of the light passing hole within 1 mm to 3 mm can ensure that the focused spot is less than 10 μm, which can effectively reduce the changes in the size and position of the spot caused by the offset of the incident light beam and ensure the processing accuracy.

[0013] Furthermore, the rotating mirror module includes a rotating mirror barrel, a driving device, a third lens, and a second mirror; the rotating mirror barrel is driven by the driving device and can rotate 360° around the center of the optical axis. Inside the rotating mirror barrel, a third lens and a second mirror inclined at 45° are fixedly installed in sequence from top to bottom along the center of the optical axis. The second mirror is horizontally facing the first mirror. The laser beam enters vertically into the inside of the rotating mirror barrel, is focused by the third lens, and then reflected by the second mirror to emit a horizontally transmitted laser beam backward. The central axis of the rotating mirror barrel coincides with the center of the internal optical axis.

[0014] The specific working principle of the rotating mirror module is as follows: By setting the rotating mirror module, the laser beam enters vertically downward into the inside of the rotating mirror barrel, exits horizontally backward from the second mirror, and will rotate 360° around the center. The emitted laser beam irradiates on each beam splitting optical path module while rotating.

[0015] Furthermore, the small aperture diaphragm is located at the focal point of the third lens.

[0016] In the rotating mirror module, a long-focus third lens is placed above the 45° second mirror, and its focal point is located at the position of the small aperture diaphragm in the beam splitting optical path module. The main function of the small aperture diaphragm is to limit the imaging of light beams with different divergence angles on the focal plane.

[0017] Furthermore, the rotational speed of the driving motor is 3000 r / min, and the emission frequency of each split laser beam is 50 Hz.

[0018] The driving motor can be a frameless torque motor. The rotational speed of the frameless torque motor is 3000 r / min, which is converted to 50 revolutions per second. The rotational speed of 50 revolutions is much lower than the repetition rate of the laser (MHz, kHz). Of course, the rotational speed of the frameless torque motor is relatively slow. The rotational speed can be increased by using the motor and gear speed change, but it is still much lower than the repetition rate of the laser. The split laser beams can be approximately uniformly distributed in space.

[0019] In actual application, the higher the rotational speed of the driving motor, the better. However, the rotational speed of the frameless torque motor on the market cannot reach a very high value, and 3000 r / min is already at a medium to upper level on the market. If the method of gear speed change is adopted, the rotational speed can be increased. The emission frequency of the split laser is calculated based on the rotational speed and has nothing to do with the repetition rate of the laser. The requirement for the laser is a high repetition rate or continuous pulses. There is no need to consider that each pulse accurately hits each light outlet in time. The laser emission frequency (Hz) of a single processing port = the rotational speed of the motor (unit: r / min) / 60.

[0020] Further, a third reflecting mirror is provided between the collimator and the rotating mirror module and is disposed at an inclination of 45°. The third reflecting mirror changes the horizontal laser beam collimated by the collimator into a vertically transmitted laser beam.

[0021] Further, the central axis of the beam splitter tube coincides with the axis of the internal optical axis.

[0022] Further, the central wavelength of the laser beam emitted by the laser is 532 nm or 1064 nm.

[0023] In the present invention, by adjusting the spacing of the optical devices and using a reflecting mirror with a working wavelength including 532 nm and 1064 nm, the optical system is simultaneously applicable to the etching of lasers with wavelengths of 532 nm and 1064 nm, while other beam splitting methods require different structures and different optical devices for the etching of 532 nm and 1064 nm lasers.

[0024] Compared with the prior art, the present invention has the following beneficial effects: (1) In the present invention, the cooperation of the rotating mirror module rotating at a high speed and multiple beam splitting optical path modules with the same lateral projection spacing realizes the beam splitting of the laser beam. The parameters of the split multiple laser beams are only related to the parameters of the laser, and there is no need to manually adjust each laser beam. At the same time, the optical imaging system is the same, and the obtained focused spots are also the same. That is, the split multiple laser beams in the present invention have the same spacing, the same line spacing, and the same energy; (2) Since the spot size and spot position of the non-collimated incident light will change after focusing, the optical path design of the present invention combining multiple lenses and a small aperture diaphragm can not only limit the imaging of the incident beams with different divergence angles on the focal plane, making the position and size of the focused spot sufficiently stable; (3) The beam splitting device is realized only by a driving device, several lenses and several mirrors, with fewer optical devices used, reducing the cost. In the prior art, a mechanical beam splitting method is adopted, which requires a large number of polarization beam splitting prisms, adjustable attenuator beam splitters and mirrors, resulting in a higher cost. (4) The beam splitting optical path system of the present invention is applicable to the beam splitting of lasers with central wavelengths of 532 nm and 1064 nm. The focusing of lasers with two wavelengths can be achieved only by moving the device positions without replacing the devices, and it is applicable to the etching of lasers with wavelengths of 532 nm and 1064 nm. For the etching of lasers with wavelengths of 532 nm and 1064 nm by other beam splitting methods, different structures need to be designed and different optical devices need to be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 It is a spatial position diagram of the rotating mirror module, the annular track and the beam splitting optical path module in Embodiment 1; Figure 2 It is a structural diagram of the equally spaced laser beam splitting device in Embodiment 1; Figure 3 It is the simulation result of the 1 mm small hole aperture of the laser beam with a central wavelength of 532 nm in Embodiment 1; Figure 4 It is the simulation result of the 5 mm small hole aperture of the laser beam with a central wavelength of 532 nm in Embodiment 2; Figure 5 It is the simulation result of the 1 mm small hole aperture of the laser beam with a central wavelength of 1064 nm in Embodiment 3; Among them, the specific reference numerals are: Laser 1, collimator 2, third mirror 3, rotating mirror module 4, annular track 5, inner track 6, outer track 7, rotating mirror barrel 8, driving device 9, third lens 10, second mirror 11, beam splitting optical path module 12, beam splitter barrel 13, first mirror 14, small hole aperture 15, first lens 16, second lens 17, moving platform 18, processed sample 19. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] Embodiment 1 This embodiment discloses an equally spaced laser beam splitting device, as Figure 1 and Figure 2 shown, which includes a laser 1, a collimator 2, a third reflector 3, a rotating mirror module 4, an annular track 5, a plurality of beam splitting optical path modules 12, and a moving platform 18; The annular track 5 is composed of an inner track 6 and an outer track 7 that are concentrically arranged in the same plane. The rotating mirror module 4 is located at the central position of the annular track 5. A plurality of beam splitting optical path modules 12 are located on the annular track 5, and the projection spacings of the plurality of beam splitting optical path modules 12 in the Y-axis direction of the annular track 5 are the same, ensuring that the laser line spacings are the same. In specific applications, the number and installation positions of the beam splitting optical path modules 12 can be reasonably arranged according to the number of beam splittings and the focal spacings. The pulse signals received by each beam splitting optical path module 12 depend on its line width on the annular track 5. As long as the line widths are the same, it can be ensured that each beam splitting optical path module 12 uniformly receives pulsed laser light, ensuring the energy consistency of each focused light spot; The laser 1 emits a laser beam. In this embodiment, the central wavelength of the laser beam emitted by the laser 1 is 532 nm. The laser beam is collimated by the collimator 2 and then enters the third reflector 3 that is inclined at 45°. The third reflector 3 changes the horizontal laser beam collimated by the collimator 2 into a vertically transmitted laser beam, and the vertically transmitted laser beam enters the rotating mirror module 4 vertically downward. The optical axis center inside the rotating mirror module 4 is perpendicular to the plane of the annular track 5. The rotating mirror module 4 can rotate 360° around the optical axis center. The emitted laser beam is emitted from the rotating mirror module 4, and the emitted laser beam uniformly irradiates each beam splitting optical path module 12 while rotating, realizing the beam splitting; After the beam splitting optical path module 12 shapes and collimates the laser beam, it focuses on the surface of the processing sample 19 located on the moving plane. The processing sample 19 is fixedly placed on the surface of the moving platform 18, and the surface of the processing sample 19 is laser scribed by the movement of the moving plane.

[0029] Among them, the beam splitting optical path module 12 includes a beam splitting lens barrel 13, a first reflector 14, a small hole aperture 15, a first lens 16, and a second lens 17; inside the beam splitting lens barrel 13, a first reflector 14, a small hole aperture 15, a first lens 16, and a second lens 17 are coaxially installed from top to bottom in sequence. The first reflector 14 is inclined at 45°, changing the horizontally transmitted laser beam emitted from the rotating mirror module 4 into a vertically transmitted laser beam. The vertically transmitted laser beam passes through the through hole of the small hole aperture 15 for shaping, and after being collimated by the first lens 16, it enters the second lens 17 for focusing. The axis inside the beam splitting lens barrel 13 is consistent with the optical axis.

[0030] The specific working principle of the spectroscopic optical path module 12 is as follows: The horizontally transmitted spectroscopic laser beam is changed into a vertically transmitted spectroscopic laser beam by the first reflector 14. Since the spot size and position of the incident light with non-collimated incidence will change after focusing, a small-aperture diaphragm 15 is arranged below the first reflector 14 to limit the imaging of incident light with different incident angles, so that the position and size of the focused spot are stable enough. Below the small-aperture diaphragm 15 is the first lens 16, which collimates the spectroscopic laser beam into a collimated beam. The collimated beam is focused on the surface of the processing sample 19 by the second lens 17 below. The scribing on the surface of the processing sample 19 is realized by the movement of the moving platform 18.

[0031] Among them, the diameter of the light-transmitting hole of the small-aperture diaphragm 15 is XX mm to XX mm. The diameter of the light-transmitting hole of the small-aperture diaphragm 15 determines the offset of the beam in the spectroscopic optical path and also determines the size of the focused spot at the same time. The larger the diameter of the light-transmitting hole of the diaphragm, the greater the offset and the larger the focused spot. Controlling the diameter of the light-transmitting hole within XX mm to XX mm can effectively reduce the changes in the spot size and position caused by the offset of the incident beam and ensure the processing accuracy. In this embodiment, the diameter of the light-transmitting hole of the small-aperture diaphragm 15 is 1 mm.

[0032] Among them, the rotating mirror module 4 includes a rotating mirror barrel 8, a driving device 9, a third lens 10 and a second reflector 11; the rotating mirror barrel 8 is driven by the driving device 9 and can rotate 360° around the optical axis center. Inside the rotating mirror barrel 8, a third lens 10 and a second reflector 11 arranged at an angle of 45° are fixedly installed in sequence along the optical axis center from top to bottom. The second reflector 11 is horizontally opposite to the first reflector 14. The laser beam vertically enters the inside of the rotating mirror barrel 8, is focused by the third lens 10, and then is reflected by the second reflector 11, and a horizontally transmitted laser beam is emitted backward. The central axis of the rotating mirror barrel 8 coincides with the internal optical axis center.

[0033] The specific working principle of the rotating mirror module 4 is as follows: By setting the rotating mirror module 4, the laser beam vertically enters the inside of the rotating mirror barrel 8, is horizontally emitted backward from the second reflector 11, and will rotate 360° around the center. The emitted laser beam irradiates on each spectroscopic optical path module 12 while rotating.

[0034] Among them, the small-aperture diaphragm 15 is located at the focal point position of the third lens 10. A long-focus third lens 10 is placed above the 45° second reflector 11 in the rotating mirror module 4, and its focal point is located at the position of the small-aperture diaphragm 15 in the spectroscopic optical path module 12. The main function of the small-aperture diaphragm 15 is to limit the imaging of beams with different divergence angles on the focal plane.

[0035] Among them, the rotational speed of the driving motor is 3000 r / min, and the emission frequency of each split laser beam is 50 Hz. The driving motor can be a frameless torque motor. The rotational speed of the frameless torque motor is 3000 r / min, which is converted to 50 revolutions per second. The rotational speed of 50 revolutions is much lower than the repetition rate (MHz, kHz) of Laser 1. Of course, the rotational speed of the frameless torque motor is relatively slow. The rotational speed can be increased by using the motor and gear speed change, but it is still much lower than the repetition rate of Laser 1. The split laser beams can be approximately uniformly distributed in space.

[0036] In this embodiment, in the zemax simulation test, the diameter of the laser beam collimated by the collimator 2 is about 6 mm. The third lens 10 in the rotating mirror module 4 is a plano-convex H-K9L lens with a radius of curvature of 103.36 mm, a focal length of 200 mm, and a thickness of 3.5 mm. The center of the second mirror 11 is at a position 180 mm below the third lens 10. The vertical distance between the center of the second mirror 11 and the small aperture stop 15 with a diameter of 1 mm is 14 mm. The first lens 16 (plano-convex H-K9L lens with a radius of curvature of 51.68 mm, a focal length of 100 mm, and a thickness of 3 mm) is 100 mm below the small aperture stop 15. After passing through the first lens 16, the light beam is collimated and refocused through the second lens 17 (plano-convex H-K9L lens with a radius of curvature of 10.34 mm, a focal length of 20 mm, and a thickness of 2.4 mm). The focusing position is 18.105 mm behind it.

[0037] Figure 3 Figure (a) is a schematic optical path diagram of the laser passing through beam expansion and collimation to reach the rotating mirror module and the subsequent part in this embodiment. Figure 3 Figure (b) shows the spot diagrams when the laser beam with a central wavelength of 532 nm is incident with offsets of 0, 0.05°, 0.1°, and 0.15° respectively in the simulation test. When the incident beam has no offset, the RMS radius of the spot is 2.145 μm; when the incident beam is offset by 0.05°, the RMS radius of the spot is 3.026 μm, and the spot position is offset by 0.032 mm on the focal plane; when the incident beam is offset by 0.1°, the RMS radius of the spot is 4.983 μm, and the spot position is offset by 0.065 mm on the focal plane; when the incident beam is offset by 0.15°, the laser beam is completely blocked by the aperture stop. From the above simulation results, it can be seen that when the offset angle of the incident beam is limited to 0.1 degree, the spot size is 4.983 μm.

[0038] Embodiment 2 This embodiment discloses an equally spaced laser beam splitting device, which is different from Embodiment 1 in that: in this embodiment, the diameter of the light passing hole of the small aperture stop 15 is 5 mm.

[0039] Figure 4 Figure (a) is a schematic optical path diagram of the laser passing through beam expansion and collimation to reach the rotating mirror module 4 and the subsequent part in this embodiment.Figure 4 (b) Spot diagrams when laser beams with a central wavelength of 532 nm are incident with offsets of 0, 0.15°, 0.5°, and 0.8° respectively, as tested by the simulation test center. When the incident beam is not offset, the RMS radius of the spot is 2.145 μm; when the incident beam is offset by 0.05°, the RMS radius of the spot is 7.595 μm, and the spot position is offset by 0.097 mm on the focal plane; when the incident beam is offset by 0.5°, the RMS radius of the spot is 18.297 μm, and the spot position is offset by 0.357 mm on the focal plane; when the incident beam is offset by 0.8°, the laser beam is completely blocked by the aperture diaphragm. From the above simulation results, it can be seen that when the offset angle of the incident beam is limited to 0.5 degrees, the spot size is 18.297 μm.

[0040] Example 3 This example discloses a laser beam splitting device with equal spacing, which is different from Example 1 in that: in this example, the central wavelength of the laser beam emitted by the laser 1 is 1064 nm, the vertical distance between the center of the second mirror 11 and the small hole diaphragm 15 with a diameter of 1 mm is 18.5 mm, and after being refocused by the second lens 17, the focal position is 18.105 mm behind it.

[0041] Figure 5 (a) Schematic diagram of the optical path of the laser in this example after beam expansion and collimation reaching the rotating mirror module 4 and thereafter. Figure 5 (b) Spot diagrams when laser beams with a central wavelength of 1064 nm are incident with offsets of 0, 0.05°, 0.1°, and 0.15° respectively, as tested by the simulation test center. When the incident beam is not offset, the RMS radius of the spot is 1.943 μm; when the incident beam is offset by 0.05°, the RMS radius of the spot is 2.886 μm, and the spot position is offset by 0.034 mm on the focal plane; when the incident beam is offset by 0.1°, the RMS radius of the spot is 4.856 μm, and the spot position is offset by 0.069 mm on the focal plane; when the incident beam is offset by 0.15°, the laser beam is completely blocked by the aperture diaphragm. From the above simulation results, it can be seen that when the offset angle of the incident beam is limited to 0.1 degree, the spot size is 4.856 μm.

[0042] From Figures 3 to 5 the simulation results in it, it can be seen that the laser beam splitting device provided by the present invention can minimize the influence of the offset of the incident beam during the rotation of the rotating mirror module 4 on the size and position of the focused spot through the diaphragm to the greatest extent, thereby ensuring the processing accuracy.

[0043] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An equidistant laser beam splitting device, characterized in that: It includes a laser, a collimator, a rotating mirror module, a circular track, a plurality of light splitting path modules and a moving platform; The annular track is composed of an inner track and an outer track which are in the same plane and are arranged with the same center, the rotating mirror module is located at the center of the annular track, a plurality of light splitting optical path modules are located on the annular track, and the projection spacing of the plurality of light splitting optical path modules in the Y-axis direction of the annular track is consistent; The laser emits a laser beam, which enters the rotating mirror module after being collimated by the collimator. The center of the optical axis inside the rotating mirror module is perpendicular to the plane of the circular track. The rotating mirror module can rotate 360° around the center of the optical axis. The laser beam is emitted from the rotating mirror module, and the emitted laser beam is evenly irradiated in each splitting optical path module while rotating. The beam splitting optical path module shapes and collimates the laser beam and then focuses the laser beam onto the surface of the processed sample located on the moving plane, and laser lines are drawn on the surface of the processed sample by moving the moving plane.

2. The equally spaced laser beam splitting device according to claim 1, characterized in that: The spectroscopic optical path module includes a spectroscopic tube, a first reflector, a pinhole diaphragm, a first lens and a second lens; the first reflector, a pinhole diaphragm, a first lens and a second lens are coaxially installed in sequence from top to bottom inside the spectroscopic tube, the first reflector is tilted at 45° to convert the horizontally transmitted laser beam emitted by the rotating mirror module into a vertically transmitted laser beam, the vertically transmitted laser beam passes through the light hole of the pinhole diaphragm for shaping, and then enters the second lens for focusing after being collimated by the first lens.

3. The equally spaced laser beam splitting device according to claim 2, characterized in that: The diameter of the light-through hole of the pinhole aperture is 1 mm to 3 mm.

4. The equally spaced laser beam splitting device according to claim 3, characterized in that: The rotating mirror module includes a rotating mirror barrel, a driving device, a third lens and a second reflector; the rotating mirror barrel is driven by the driving device and can rotate 360° around the center of the optical axis. The inside of the rotating mirror barrel is provided with a third lens and a second reflector inclined at 45°, which are sequentially installed from top to bottom along the center of the optical axis. The second reflector is horizontally arranged opposite to the first reflector. The laser beam enters the rotating mirror barrel vertically, is focused by the third lens, and then is reflected by the second reflector to emit a horizontally transmitted laser beam backwards.

5. The equally spaced laser beam splitting device according to claim 4, characterized in that: The pinhole stop is located at the focal position of the third lens.

6. The equally spaced laser beam splitting device according to claim 4, characterized in that: The rotation speed of the driving device is 3000r / min, and the output frequency of each split laser beam is 50Hz.

7. The equally spaced laser beam splitting device according to claim 1, characterized in that: A third reflector inclined at 45° is provided between the collimator and the rotating mirror module, and the third reflector converts the horizontal laser beam collimated by the collimator into a vertically transmitted laser beam.

8. The equally spaced laser beam splitting device according to claim 2, characterized in that: The central axis of the beam splitter tube coincides with the center of the internal optical axis.

9. The equally spaced laser beam splitting device according to claim 1, characterized in that: The central wavelength of the laser beam emitted by the laser is 532nm or 1064nm.

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