Precision machining system

Abstract

The invention relates to the technical field of laser machining, and provides a precision machining system which comprises a laser device, a laser emitting module, a flexible transmission module and a micromachining module which are sequentially connected through a light path. The laser is used for generating ultrafast laser beams, and the ultrafast laser beams are collimated, focused and coupled through the laser emission module to achieve high-quality transmission. The flexible transmission module adopts an armored hollow-core anti-resonance optical fiber to be combined with a suspension system, so that the stability of light beam transmission in a dynamic environment is ensured. The micromachining module integrates a light beam adjusting module and a polarization control module, and the material removal efficiency and the machining surface quality are improved by optimizing the laser polarization state. The laser processing head is formed by combining a high-speed scanning galvanometer and an F-theta lens, and precise focusing and rapid scanning in a three-dimensional space are achieved. Through the synergistic effect of ultrafast laser, flexible transmission of the hollow-core anti-resonance optical fiber and polarization regulation and control, a laser processing system with high stability, high flexibility and high precision is formed, and the laser processing system is very suitable for the field of micro-nano precision processing.

Description

Technical Field

[0001] The present invention relates to the field of laser processing technology, and particularly relates to a precision processing system, which is applicable to fields such as micro-nano precision processing, medical device manufacturing, and optical element preparation, and particularly meets the stringent requirements for high precision, high stability, and high efficiency in industrial scenarios. Background Art

[0002] In recent years, ultrafast laser processing technology has been widely used in the field of precision microfabrication due to its extremely high processing precision, extremely small heat-affected zone, and wide adaptability to various materials. However, there are significant bottlenecks in high-power transmission, dynamic polarization control, and system coordination in the existing technology, which severely restrict the high-efficiency and high-precision processing requirements of various workpieces.

[0003] First of all, traditional beam transmission schemes are difficult to balance high power and industrial-level flexibility requirements. Currently, free-space optical paths rely on rigid mirror group packaging. Although solid-core fibers help with flexible transmission to a certain extent, in this case, large bending losses and strong nonlinear effects will cause pulse broadening and spectral distortion at high peak powers, and their low damage threshold severely limits the reliability of continuous processing. In 10.1117 / 12.2288263 published in 2018, during the drilling of a 0.3-mm-thick stainless steel sheet, after transmission through a solid-core fiber, the hole wall taper >2°, and the free-space system also had a roundness deviation of 1.5 μm due to insufficient optical path stability, making it difficult to meet the dual requirements of high precision and flexibility for complex material processing. Although there are existing technologies that adopt the scheme of hollow anti-resonant fibers (such as CN107621677A), by coupling the laser into the hollow fiber for transmission, utilizing its low loss (34 dB / km) and wide bandwidth (200 - 800 THz) characteristics, and integrating a water cooling and gas management system to improve high-power transmission capabilities, it is still limited to static transmission scenarios, lacking system coordination between transmission and application and stability guarantee in a dynamic environment.

[0004] In addition, the influence of the laser polarization state on the quality of complex processing is also particularly significant. Existing hollow fiber schemes (such as CN108351465A) do not address the polarization control problem, which will lead to uneven processing quality. In the case of a static polarization state, linearly polarized light, due to its directional electric field distribution, generates non-uniform absorption in different incident angle regions on the curved surface, ensuring power concentration and utilization; circularly polarized light can reduce the thermal gradient through symmetric electric field distribution, thereby significantly improving processing consistency. However, due to severe polarization angle shift caused by thermal load during continuous processing in traditional schemes, the quality of processing results deteriorates. At this time, the polarization extinction ratio of the solid-core fiber deteriorates from 25 dB to less than 15 dB due to modal perturbation, unable to meet the stringent requirements of dynamic continuous material processing.

[0005] Finally, due to the split design of the transmission, control, and processing modules in the prior art, the efficiency and synergy are significantly reduced, resulting in a decline in systematic performance. In complex processing, the optical path needs to be frequently adjusted, and affected by environmental vibration, the solid-core optical fiber causes deterioration of the beam quality. The M 2 factor increases from 1.1 to 1.5, the focus shift has a significant impact, and the diameter of the focused spot expands from 5μm to 6.5μm, greatly limiting the precision processing ability. At the same time, most of the current free-space optical paths rely on a five-axis calibration mechanism to compensate for vibration and thermal drift. The parameter coordination of pulse energy, polarization state, and galvanometer path depends on manual experience. The single calibration takes more than 30 minutes, and the system switching takes more than 1 hour. As a result, the processing consistency fluctuation is greater than 15%, and the production capacity utilization rate is less than 60%, significantly deviating from the intelligent standard of Industry 4.0. Summary of the Invention

[0006] The object of the present invention is to provide a precision processing system, which solves the problems of difficult flexible transmission of traditional spatial optical paths, damage and pulse distortion of solid-core optical fibers under high-power ultrafast lasers, as well as insufficient system synergy and polarization control defects of hollow anti-resonant optical fibers, so as to meet the high-precision processing requirements of materials.

[0007] A precision processing system includes a laser, a laser emission module, a flexible transmission module, and a micro-processing module that are optically connected in sequence, wherein:

[0008] The laser is used to generate an ultrafast laser beam and emit the laser beam to the laser emission module;

[0009] The laser emission module is composed of a beam collimation module and a focusing and coupling module arranged coaxially. The beam collimation module straightens the laser beam output by the laser and adjusts its divergence angle ≤ 0.5 mrad. The focusing and coupling module couples the collimated beam to the flexible transmission module;

[0010] The flexible transmission module includes an armored hollow anti-resonant optical fiber and a suspension system. The hollow anti-resonant optical fiber is fixed inside the armored cable. Its input end is connected to the focusing and coupling module, and the output end is connected to the micro-processing module. The suspension system is connected to the ceiling to achieve dynamic stable transmission of the armored hollow anti-resonant optical fiber in a vertical state and guide the laser beam into the micro-processing module;

[0011] The microfabrication module includes a beam adjustment module, a polarization control module, and a laser processing head. The beam adjustment module is used to collimate the laser beam at the output end of the hollow anti-resonant fiber, form an output collimated beam with the same characteristics as the incident collimated beam, and emit the output collimated beam to the polarization control module. The polarization control module is used to adjust the polarization state of the output collimated beam and irradiate it to the laser processing head through reflection. The laser processing head is integrated with a high-speed scanning galvanometer and an F-θ lens, and is used to realize the focusing and scanning processing of the laser beam in three-dimensional space.

[0012] The workbench has X-axis and Y-axis displacement functions, is used to fix and position the workpiece, and cooperates with the laser processing head to complete the precision machining of the workpiece.

[0013] Preferably, the beam collimation module includes a first mirror, a second mirror, and a third mirror arranged in sequence along the laser transmission direction, all of which are set as adjustable structures for spatially collimating the laser beam and correcting the beam pointing.

[0014] Preferably, the focusing and coupling module includes a focusing lens and a coupling device, where:

[0015] For the focusing lens, its focal length f satisfies: where ω is the spot radius incident on the lens surface, D1 is the core diameter of the input end of the hollow anti-resonant fiber, and λ is the wavelength, and it is used to focus the modulated polarized beam to a focus with a diameter smaller than the core diameter D1.

[0016] The coupling device includes a copper cavity and a three-dimensional displacement stage. The copper cavity is fixed on the three-dimensional displacement stage through a connecting piece. The copper cavity is provided with a V-shaped groove, and the opening angle of the V-shaped groove is 60° - 120°, preferably 90°, and is used to position and fix the input end of the hollow anti-resonant fiber, and adjust the spatial position of the fiber input end and the laser beam focus through the three-dimensional displacement stage.

[0017] Preferably, the laser is a 1064nm picosecond solid-state laser, and the repetition frequency and average power of the laser are adjustable.

[0018] Preferably, the transmission loss of the hollow anti-resonant fiber at a pump wavelength of 1064nm is 0.05 - 0.2dB / m, preferably 0.1dB / m; the coating layers at both ends of the hollow anti-resonant fiber are respectively stripped with a length of 0.8 - 1.5cm, preferably 1cm.

[0019] Preferably, the armored cable is made of stainless steel material, and metal rods are respectively fixed at both ends. Cylindrical openings are provided inside the metal rods, and the cylindrical openings are respectively connected to the input end and the output end of the hollow anti-resonant fiber.

[0020] Preferably, the suspension system includes at least two sets of elastic cords to reduce the fluctuation of the armored hollow anti-resonant fiber during movement.

[0021] Preferably, the beam adjustment module includes a holder, a six-axis adjustment stage, and a collimating lens, where:

[0022] The holder is arranged at the top and is used to fix the metal rod at the output end of the armored hollow anti-resonant fiber;

[0023] The six-axis adjustment is used to adjust the direction of the output laser beam at the output end of the hollow anti-resonant fiber and emit the output laser beam to the collimating lens;

[0024] The collimating lens is used to collimate the output laser beam to form an output collimated laser beam and emit the output collimated laser beam to the polarization control module;

[0025] Preferably, the microfabrication module further includes a fourth mirror, a connecting rod, and a C-shaped plate. The beam adjustment module, the polarization control module, and the fourth mirror together form a cage system, and a stable optical system is formed by connecting the C-shaped plate through the connecting rod.

[0026] Preferably, the polarization control module includes a half-wave plate and a quarter-wave plate, and by rotating the angle of the wave plate, it is used to convert the collimated laser beam into any polarization state.

[0027] Preferably, the input end of the hollow anti-resonant fiber is fixed in the groove of the copper cavity by vacuum glue. The vacuum glue is a high-temperature resistant epoxy resin glue, and its temperature resistance range after curing is -45°C to 120°C.

[0028] Preferably, the diameter D2 of the focal spot of the focused lens coupling the laser beam at 1 / e 2 is 0.6 to 0.7 times the core diameter D1 of the incident end of the hollow anti-resonant fiber.

[0029] Preferably, the top of the focused lens is provided with a first water-cooling pipe and a second water-cooling pipe. The two sides of the coupling device are respectively provided with a third water-cooling pipe and a fourth water-cooling pipe. The first water-cooling pipe, the second water-cooling pipe, the third water-cooling pipe, and the fourth water-cooling pipe are connected to a water chiller through pipelines for the circulating injection and discharge of cooling water. The temperature of the water chiller is controlled within the range of 19.5 to 20.5°C.

[0030] Preferably, the metal rod at the output end is provided with a capillary tube to nest the hollow anti-resonant fiber to match the aperture size.

[0031] Preferably, the focal length of the collimating lens is the same as that of the focusing lens.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] A precision machining system provided by the present invention uses a hollow anti-resonant fiber as a flexible transmission medium for ultrafast lasers, and through an armored suspension structure, ensures the efficient and stable transmission of lasers in a dynamic environment, significantly weakening the nonlinear effects (such as self-focusing and spectral broadening) and transmission losses caused by air during laser transmission. At the same time, combined with polarization control, the machining accuracy and material adaptability are effectively improved. This system has important application values in the fields of precision micro-machining, medical device manufacturing, optical element preparation, etc., and is particularly suitable for industrial scenarios with strict requirements for machining accuracy and stability. Description of the Drawings

[0034] Figure 1 It is a schematic optical path diagram of a precision machining system according to an embodiment of the present invention.

[0035] Figure 2 It is the power stability and pointing stability of the output laser measured at 20W.

[0036] Figure 3 It is a diagram of the linearly polarized machining result obtained by measurement.

[0037] Figure 4 It is a diagram of the circularly polarized machining result obtained by measurement.

[0038] In the figure: 1 - laser;

[0039] 2 - laser emission module; 21 - first reflector; 22 - second reflector; 23 - third reflector; 24 - focusing lens; 241 - first water-cooling pipe; 242 - second water-cooling pipe; 25 - coupling device; 251 - third water-cooling pipe; 252 - fourth water-cooling pipe; 26 - water chiller;

[0040] 3 - armored hollow anti-resonant fiber; 31 - hollow anti-resonant fiber; 311 - incident end of the hollow anti-resonant fiber; 312 - exit end of the hollow anti-resonant fiber; 331 - first elastic cord; 332 - second elastic cord; 321 - first cylindrical metal rod; 322 - second cylindrical metal rod;

[0041] 4 - micro-machining module; 41 - gripper; 42 - connecting rod; 43 - six-axis adjustment frame; 44 - C-shaped plate; 45 - collimating lens; 46 - polarization control module; 461 - half-wave plate; 462 - quarter-wave plate; 47 - fourth reflector; 48 - laser processing head; 481 - first galvanometer; 482 - second galvanometer; 483 - F-θ lens;

[0042] 5 - Workbench; Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the present invention clearer, the following further describes in detail the specific implementation manners of the present invention with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention but not to limit the scope of the present invention.

[0044] Figure 1 The present invention provides an ultrafast laser flexible transmission processing system applicable to complex curved surfaces, which mainly includes: a laser 1, a laser emission module 2, a flexible transmission module, and a micro - processing module 4.

[0045] As Figure 1 shown, the laser 1 uses a commercial picosecond solid - state laser, with a central wavelength of 1064 nm, an average power as high as 50 W, a pulse duration of less than 15 ps, a repetition frequency range of 50 kHz to 1500 kHz, and the emitted laser beam is vertically linearly polarized. The laser 1 has the functions of adjustable repetition frequency and average power, and can flexibly adjust laser parameters according to processing requirements.

[0046] The laser emission module 2 includes a beam collimation module and a focusing and coupling module.

[0047] The beam collimation module is composed of a first mirror 21, a second mirror 22, and a third mirror 23. The laser beam emitted by the laser 1 is vertically linearly polarized light. First, it enters the second mirror 22 after passing through the first mirror 21, and then is collimated and reflected by the third mirror 23 to ensure the spatial collimation of the beam. The angles and positions of the three mirrors are adjustable;

[0048] The focusing and coupling module includes a focusing lens 24 and a coupling device 25. In this embodiment, the radius ω of the laser beam leaving the end - cap of the high - power picosecond laser 1 is about 2.25 mm, the focal length of the focusing lens 24 is 7.5 cm, and it has a high light transmittance. It can focus the circularly polarized beam to the focal point and then enter the hollow anti - resonant fiber. Among them, the spot diameter at the focal point is smaller than the core diameter of the anti - resonant fiber. The diameter D2 at the 1 / e2 of the focal spot of the focusing lens 24 is 0.6 - 0.7 times the core diameter D1.

[0049] The coupling device 25 includes a copper cavity and a three-dimensional displacement stage. The copper cavity has good thermal conductivity and is internally provided with a V-shaped groove with an opening angle of 90°, which is used to fix the input end of the hollow anti-resonant fiber 31. The copper cavity is fixed to the three-dimensional displacement stage through a connecting piece. The adjustment resolution of the three-dimensional displacement stage is 20 nm. By manually rotating the knob of the three-dimensional displacement stage, the spatial position of the fiber is controlled to make the focused spot better match the mode of the hollow anti-resonant fiber 31, thereby improving the coupling efficiency. In addition, it should be noted that in order to achieve the optimal coupling conditions, during the actual operation, the second mirror 22 and the third mirror 23 can be tuned to precisely control the front-back, left-right, and up-down positions of the focused spot, so that the focused spot is coupled into the fiber core, and the coupling efficiency can reach more than 91%.

[0050] In this embodiment, a water cooling system is used to reduce the thermal effect under high laser power, thereby improving the power stability and pointing stability of the system. Specifically, a first water cooling pipe 241 and a second water cooling pipe 242 are arranged on the top of the focusing lens 24, and a third water cooling pipe 251 and a fourth water cooling pipe 252 are respectively arranged on both sides of the coupling device 25. The first water cooling pipe 241, the second water cooling pipe 242, the third water cooling pipe 251, and the fourth water cooling pipe 252 are connected to the water cooler 26 through pipelines for circulating injection and discharge of cooling water. The temperature of the water cooler is controlled within the range of 19.5 - 20.5 °C.

[0051] The hollow anti-resonant fiber guides light based on the anti-resonant theory (anti-resonant reflecting optical waveguide, ARROW). Its cladding tube wall can be approximately regarded as a Fabry-Perot cavity. Light with a resonance wavelength (n is the refractive index of quartz, and m is the resonance order which can only take positive integers) will leak outside the fiber cladding, and light with an anti-resonance wavelength (n is the refractive index of quartz, and h is the anti-resonance order which can only take positive integers) will be confined to the air core for transmission. Therefore, the light guiding passband can be very wide (200 - 800 THz), and the loss is very small.

[0052] In this embodiment, the length of the hollow anti-resonant fiber 31 is 3 m, and the fiber loss is measured to be 0.1 dB / m at the pump wavelength of 1064 nm. The stripped lengths at both ends are 1 cm respectively to avoid thermal damage caused by uncoupled laser power.

[0053] The hollow anti-resonant fiber 31 is composed of 6 capillaries to form an annular cladding. The average diameter d1 of the capillaries is 22.5 μm, and the average diameter D1 of the core is 35.5 μm. By defining the ratio of d1 / D1 to be close to 0.68, single-mode conduction is ensured.

[0054] Flexible transmission module, including armored hollow anti-resonant fiber 3 and suspension system. The hollow anti-resonant fiber 31 is wrapped in an armored cable to form the armored hollow anti-resonant fiber 3. After encapsulation, the minimum bending radius of the fiber is 30 cm. The armored cable is made of stainless steel, which can enhance the mechanical strength of the fiber, enabling it to withstand external pressure and not be easily worn. At both ends of the armored hollow anti-resonant fiber 3, a first cylindrical metal rod 321 and a second cylindrical metal rod 322 are fixedly provided, connecting the input end 311 of the hollow anti-resonant fiber and the output end 312 of the hollow anti-resonant fiber respectively. A capillary tube is also provided inside the second metal rod 322 to nest the hollow anti-resonant fiber to match the aperture size. The first cylindrical metal rod 321 has a length of 10 cm and a diameter of 15 mm; the second cylindrical metal rod 322 has a length of 15 cm and a diameter of 15 mm. A cylindrical opening with a diameter of 2.8 mm is provided inside the metal rod for fixing the fiber.

[0055] In this embodiment, the input end 311 of the hollow anti-resonant fiber, the hollow anti-resonant fiber 31, and the output end 312 of the hollow anti-resonant fiber are integrated. It should be noted that Figure 1 the hollow anti-resonant fiber 31 in

[0056] only indicates a part of the fiber sleeved in the first cylindrical metal rod 321, not the entire fiber.

[0057] The micro-processing module 4 includes a beam adjustment module, a polarization control module, and a laser processing head.

[0058] The beam adjustment module includes a holder 41, a six-axis adjustment frame 43, a collimating lens 45, a fourth mirror 74, a connecting rod 42, and a C-shaped plate 44. The connecting rod 42 is connected to the C-shaped plate 44 and encapsulated to form a cage device to ensure the high-precision alignment and long-term stable operation of the optical system.

[0059] The holder 41 is an adjustable automatic centering adjustment frame for stabilizing the end position of the armored hollow anti-resonant fiber 3;

[0060] The six-axis adjustment frame 43 is used to adjust the direction of the laser beam output from the hollow anti-resonant fiber 31 to ensure that the center of the laser beam coincides with the optical axis of the collimating lens 45;

[0061] The focal length of the collimating lens 45 is the same as that of the focusing lens 24, both being 7.5 cm, to achieve the best collimation effect. The collimating lens 45 converts the divergent laser beam into a collimated parallel laser beam;

[0062] The polarization control module 46 includes a half-wave plate 461 and a quarter-wave plate 462. After the laser beam is transmitted through the armored hollow anti-resonant fiber 3, for linear polarization processing, the wave plates are rotated to make the fast axes of the half-wave plate 461 and the quarter-wave plate 462 parallel or perpendicular; for circular polarization processing, the wave plates are rotated to make the fast axes of the half-wave plate 461 and the quarter-wave plate 462 at 45°.

[0063] The fourth mirror 47 is used to reflect the collimated parallel laser beam to the laser processing head 48.

[0064] The laser processing head 48 includes a first galvanometer 481, a second galvanometer 482 and an F-θ lens 483. The first galvanometer 481 and the second galvanometer 482 form movements in the X and Y planes, which are used to reflect the laser and achieve high-precision scanning. By moving the mirror, the collimated parallel laser beam is then focused on the surface of the workpiece by the F-θ lens 483.

[0065] The workbench 5 has the functions of X-axis and Y-axis displacement, which is used to fix and position the workpiece, and cooperates with the laser processing head 48 to complete the precision processing of the workpiece.

[0066] As an alternative embodiment, it should be noted that due to the low nonlinearity and dispersion value of the hollow anti-resonant fiber, the pulse time width and spectral distribution at the output port do not change significantly, and the influence of the nonlinear effect on the transmitted beam can be ignored. When the pulse width of the transmitted high-power laser is as short as a few picoseconds or even shorter, the modulation of the nonlinear effect on the beam cannot be ignored. If the original pulse parameters are to be kept unchanged, the inside of the hollow anti-resonant fiber needs to be evacuated to ensure that the laser transmitted in the hollow anti-resonant fiber is in a vacuum state, avoiding the occurrence of the nonlinear effect caused by air. The specific implementation steps are as follows: seal the input end 311 and the output end 312 of the hollow anti-resonant fiber to maintain good airtightness, connect to a vacuum pump for pumping air, and then fill with inert gas.

[0067] Figure 2 It is the measured power stability and pointing stability of the output laser at 20W. During the 30-minute recording, the root mean square (RMS) value of the power fluctuation is 0.21% in both cases, and the pointing stabilities in two orthogonal directions are Delta x: 14.04 and Delta y: 9.93 respectively. The test results show that the armored hollow anti-resonant fiber can achieve stable transmission.

[0068] The electric field vibration direction of linearly polarized light is fixed. When the laser polarization direction is consistent with the cutting direction, the material has a higher absorption rate for the laser, and high-precision scribing can be achieved.

[0069] Figure 3 It is the measured result diagram of linear polarization processing.

[0070] Specifically, the laser pulse repetition frequency is set to 1.5 MHz, the pulse energy on the workpiece surface is 13 μJ, corresponding to an average laser power of 20 W. At a scanning speed of 4 mm / s, a single linear machining was performed by repeating the scan. The test results show that the machining marks are relatively straight without obvious bending.

[0071] The electric field direction of circularly polarized light rotates uniformly, eliminating the direction dependence of linearly polarized light, and is suitable for machining complex shapes or round holes.

[0072] Figure 4 It is a diagram of the machining result of circular polarization measured.

[0073] Specifically, the laser pulse repetition frequency is set to 84 kHz, the pulse energy on the workpiece surface is 100 μJ, corresponding to an average laser power of 8 W. Drilling machining was carried out at a scanning speed of 40 mm / s. The results show that both the outer hole and the inner hole are relatively perfect circles.

[0074] A precision machining system provided by the present invention uses a hollow anti-resonant fiber as a flexible transmission medium for ultrafast lasers, and through an armored suspension structure, ensures the efficient and stable transmission of lasers in a dynamic environment, significantly reducing the nonlinear effects (such as self-focusing, spectral broadening) and transmission losses caused by air during laser transmission. At the same time, combined with polarization control, the machining accuracy and material adaptability are effectively improved. This system has important application value in the fields of precision micro-machining, medical device manufacturing, optical element preparation, etc., and is particularly suitable for industrial scenarios with strict requirements for machining accuracy and stability.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A precision machining system, comprising a laser, a laser emission module, a flexible transmission module, and a micro-machining module connected in sequence in an optical path, and a workbench for fixing a workpiece; wherein: The laser is used to generate an ultrafast laser beam and emit the laser beam to the laser emission module; The laser emission module is composed of a beam collimation module and a focusing and coupling module arranged coaxially. The beam collimation module straightens the laser beam output by the laser and adjusts its divergence angle ≤ 0.5 mrad, and the focusing and coupling module couples the collimated beam to the flexible transmission module; The flexible transmission module includes an armored hollow anti-resonant fiber and a suspension system. The hollow anti-resonant fiber is encapsulated inside the armored cable. Its input end is connected to the focusing and coupling module, and its output end is connected to the micro-machining module; the suspension system is suspended from the ceiling to achieve dynamic stable transmission of the armored hollow anti-resonant fiber in a vertical state and guide the laser beam into the micro-machining module; The micro-machining module includes a beam adjustment module, a polarization control module, and a laser processing head. The beam adjustment module is used to collimate the laser beam at the output end of the hollow anti-resonant fiber to form an output collimated beam with the same characteristics as the incident collimated beam, and emit the output collimated beam to the polarization control module; the polarization control module is used to adjust the polarization state of the output collimated beam and irradiate it to the laser processing head through reflection. The laser processing head is integrated with a high-speed scanning galvanometer and an F-θ lens, and is used to achieve focusing and scanning processing of the laser beam in three-dimensional space; The workbench is configured with X-axis and Y-axis displacement functions, and cooperates with the laser processing head to complete precision machining of the workpiece.

2. The precision machining system according to claim 1, wherein, The beam collimation module includes a first mirror, a second mirror, and a third mirror arranged in sequence along the laser transmission direction, all of which are set as adjustable structures for spatial collimation of the laser beam and beam pointing correction.

3. A precision machining system according to claim 1, characterized in that, The focusing and coupling module includes a focusing lens and a coupling device, wherein: The focusing lens has a focal length f that satisfies: where ω is the spot radius incident on the lens surface, D1 is the core diameter of the hollow anti-resonant fiber input end, and λ is the wavelength, which is used to focus the modulated polarized light beam to a focal point with a diameter smaller than the core diameter D1; The coupling device includes a copper cavity and a three-dimensional displacement stage. The copper cavity is fixed on the three-dimensional displacement stage through a connecting piece. The copper cavity is provided with a V-shaped groove, and the opening angle of the V-shaped groove is 60° - 120°, preferably 90°, for positioning and fixing the input end of the hollow anti-resonant fiber, and adjusting the spatial position of the fiber input end and the laser beam focus through the three-dimensional displacement stage.

4. A precision machining system according to claim 1, characterized in that, The laser is a 1064 nm picosecond solid-state laser, and the repetition frequency and average power of the laser are adjustable.

5. A precision machining system according to claim 1, characterized in that, The transmission loss of the hollow anti-resonant fiber at a pump wavelength of 1064 nm is 0.05 - 0.2 dB / m, preferably 0.1 dB / m; the coating layers at both ends of the hollow anti-resonant fiber are respectively peeled off with a length of 0.8 - 1.5 cm, preferably 1 cm.

6. A precision machining system according to claim 1, characterized in that, The armored cable is made of stainless steel material, and metal rods are respectively fixed at both ends thereof. Cylindrical openings are provided inside the metal rods, and the cylindrical openings are respectively connected to the input end and the output end of the hollow anti-resonant fiber.

7. A precision machining system according to claim 1, wherein, The suspension system includes at least two groups of elastic ropes to reduce the fluctuation of the armored hollow anti-resonant fiber during movement.

8. A precision machining system according to claim 1, wherein, The beam adjustment module includes a holder, a six-axis adjustment stage, and a collimating lens, where: The holder is arranged at the top and is used to fix the metal rod at the output end of the armored hollow anti-resonant fiber; The six-axis adjustment is used to adjust the direction of the output laser beam at the output end of the hollow anti-resonant fiber and emit the output laser beam to the collimating lens; The collimating lens is used to collimate the output laser beam to form an output collimated laser beam and emit the output collimated laser beam to the polarization control module.

9. A precision machining system according to claim 1, characterized in that, The microfabrication module further includes a fourth mirror, a connecting rod, and a C-shaped plate. The beam adjustment module, the polarization control module, and the fourth mirror together form a cage device, and a stable optical system is formed by connecting the C-shaped plate through the connecting rod.

10. A precision machining system according to claim 1, characterized in that, The polarization control module includes a half-wave plate and a quarter-wave plate, and is used to convert the collimated laser beam into any polarization state by rotating the angle of the wave plate.

11. A precision machining system according to claim 3, characterized in that, The input end of the hollow anti-resonant fiber is fixed in the groove of the copper cavity by vacuum glue. The vacuum glue is a high-temperature resistant epoxy resin glue, and the temperature resistance range after curing is -45°C to 120°C.

12. A precision machining system according to claim 3, characterized in that, The diameter D2 of the focal spot of the focused lens-coupled laser beam at 1 / e 2 is 0.6 to 0.7 times the core diameter D1 of the incident end of the hollow anti-resonant fiber.

13. A precision machining system according to claim 3, wherein, The top of the focusing lens is provided with a first water-cooling pipe and a second water-cooling pipe. The two sides of the coupling device are respectively provided with a third water-cooling pipe and a fourth water-cooling pipe. The first water-cooling pipe, the second water-cooling pipe, the third water-cooling pipe, and the fourth water-cooling pipe are connected to a water chiller through pipelines for circulating injection and discharge of cooling water, and the temperature of the water chiller is controlled within the range of 19.5 to 20.5°C.

14. A precision machining system according to claim 6, wherein, A capillary is provided on the metal rod at the output end to nest the hollow anti-resonant fiber to match the aperture size.

15. A precision machining system according to claim 3 or 8, characterized in that, The focal length of the collimating lens is the same as that of the focusing lens.

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