Optical path optimization based on galvanometer for ripple-free femtosecond laser processing device and method

Abstract

The application provides a mirror path optimization-based ripple-free femtosecond laser processing device and method, and the method comprises the following steps: S1, connecting a special fixture with a rotating C shaft; S2, clamping a processing workpiece on the special fixture; S3, making a laser beam generated by a femtosecond laser pass through a two-dimensional scanning mirror and a field lens to irradiate the surface of the processing workpiece after focusing; S4, making the two-dimensional scanning mirror control the processing path of the laser focal point in the processing workpiece plane to cooperate with the rotating C shaft to process the circumferential direction of the workpiece surface; and S5, optimizing the laser pulse energy processing process parameters to optimize the processing process. The two-dimensional scanning mirror system is used to implement precise path planning and optimization on the workpiece surface in the X-Y plane, effectively suppresses the periodic fluctuation problem caused by the change of the laser spot pulse overlap rate in the rotating processing process, realizes ripple-free high-precision contour processing, and greatly improves the quality level of the processed surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of femtosecond laser processing, in particular to a ripple-free femtosecond laser processing device and method based on path optimization of a galvanometer. BACKGROUND

[0002] Femtosecond laser (Femtosecond laser) has significant advantages in micro-nano scale processing field due to its ultra-short pulse (10 -15 s) and extremely high peak power. Its unique "cold processing" characteristics do not form recast layer, micro-cracks, etc. in the material surface processing area, almost eliminating the thermal damage of thermal diffusion to the processing area; and using the nonlinear absorption effect of femtosecond laser, high-precision removal of materials can be achieved, so it is widely used in microelectronic device manufacturing, optical element microstructure processing, biological medicine, microfluidic chip preparation and other high-precision demand fields.

[0003] The typical processing device of femtosecond laser usually adopts the mode of scanning galvanometer and rotating shaft (C-axis) working together to realize processing, in which the scanning galvanometer is responsible for controlling the motion trajectory of the laser focus in the plane, and the C-axis drives the workpiece to rotate to realize the circumferential processing coverage. However, this motion control mode has two key technical defects: first, there is a lack of dynamic coordination mechanism between the scanning path planning and the rotating speed of the C-axis, resulting in periodic fluctuations in the overlap rate of laser pulses in the rotating direction. Such fluctuations will directly translate into the periodic ripple profile of the processed surface; second, the existing path planning algorithm mostly adopts the linear or spiral trajectory mode with fixed scanning pitch, which is difficult to dynamically adjust the scanning parameters according to the local curvature change when processing complex curved surfaces, further aggravating the generation of ripple, and the consistency of surface quality is difficult to guarantee, which becomes a key bottleneck restricting the wide application of laser technology in the field of precision manufacturing.

[0004] Especially when it comes to rotating workpieces (such as disc-shaped workpieces), the matching problem of workpiece rotating speed and laser scanning path is particularly prominent. If the rotating speed is improper or the scanning path planning is unreasonable, it is easy to form "M" profile ripple on the processed surface, which is caused by the periodic interference between the scanning direction and the workpiece rotation.

[0005] In view of this, the present application proposes an innovative femtosecond laser processing device and method, which aims to realize high-precision, ripple-free processing of various shaped workpieces by precisely controlling the rotating speed of the workpiece and optimizing the processing path of the scanning galvanometer, combined with the high degree of freedom of the five-dimensional precision motion platform. This method is not only suitable for micro-nano processing of conventional materials, but also particularly suitable for manufacturing of optical elements and precision mechanical parts with extremely high surface quality requirements, and has wide application prospect and significant technical advantages. SUMMARY

[0006] Aiming at the defects in the prior art, the present application aims to provide a galvanometer path-optimized ripple-free femtosecond laser processing device and method.

[0007] According to the present application, a galvanometer path-optimized ripple-free femtosecond laser processing device is provided, comprising:

[0008] a femtosecond laser, a beam expander, an attenuator, a mirror, a two-dimensional scanning galvanometer, and an F-θ field lens;

[0009] The femtosecond laser is used to generate an ultrashort pulse laser beam that propagates along a preset path; the preset path includes making the ultrashort pulse laser beam pass through the beam expander, the attenuator, the mirror, the two-dimensional scanning galvanometer, and the F-θ field lens in sequence;

[0010] The beam expander is used to expand the diameter of the laser beam, control the divergence angle, optimize the transmission efficiency, and maintain the focusing performance at a preset distance;

[0011] The attenuator is used to reduce the energy intensity of the laser beam;

[0012] The mirror is used to change the propagation direction of the laser beam;

[0013] The two-dimensional scanning galvanometer is used to adjust the direction and focal length of the laser beam;

[0014] The F-θ field lens is used to correct the nonlinear relationship of the laser beam deflection.

[0015] Preferably, it further comprises:

[0016] a Z-axis, a processing workpiece, a special fixture, a rotating C-axis, a support frame, a rotating A-axis, a Y-axis, and an X-axis;

[0017] The two-dimensional scanning galvanometer is fixed on the Z-axis to adjust the focusing of the laser spot diameter on the surface of the processing workpiece; after the laser spot is focused, the two-dimensional scanning galvanometer controls the scanning path planning of the laser focal point in the X-Y plane on the surface of the processing workpiece;

[0018] The processing workpiece is fixed on the special fixture;

[0019] The special fixture is connected with the rotating C-axis;

[0020] The rotating C-axis is connected with the motion stage A-axis, Y-axis, and X-axis through the support frame.

[0021] Preferably, the rotating C-axis is rotated to drive the special fixture and the processing workpiece to rotate, thereby completing the processing of the surface of the processing workpiece in the circumferential direction.

[0022] Preferably, the material of the mirror comprises silver-coated or aluminum-coated glass or quartz; the material of the beam expander comprises optical glass or quartz; the attenuator comprises a neutral density filter or a variable attenuator; and the material of the F-Theta field mirror comprises fused quartz.

[0023] Preferably, the special fixture is made of aluminum alloy.

[0024] Preferably, the femtosecond laser generates a laser beam with a wavelength of 1030 nm, a beam quality M 2 <1.2, a pulse width of 290 fs, a maximum single-pulse energy of 400 muJ, and an adjustable repetition frequency of 60 Hz-1000 kHz.

[0025] Preferably, the maximum rotating speed of the rotating C-axis is 600 rpm, the maximum load is 10 kg, and the repeat positioning accuracy is 3".

[0026] Preferably, the focal length of the F-Theta field mirror is between 60 mm and 100 mm.

[0027] Preferably, the two-dimensional scanning galvanometer adopts a strip-shaped laser reciprocating scanning mode in the X-Y plane, and the rotating speed of the adapted rotating C-axis is not more than 1.0 rpm.

[0028] According to the present application, a kind of based on mirror path optimization's no ripple femtosecond laser processing method is provided, comprising:

[0029] Step S1: connect the special fixture with the rotating C-axis;

[0030] Step S2: clamp the processing workpiece on the special fixture;

[0031] Step S3: make the laser beam generated by femtosecond laser pass through two-dimensional scanning galvanometer and field mirror and focus on the surface of processing workpiece;

[0032] Step S4: control the processing path of laser focus point in the plane of processing workpiece by two-dimensional scanning galvanometer, and process the surface of workpiece in circumferential direction by rotating C-axis;

[0033] Step S5: further optimize the processing process by optimizing laser pulse energy processing process parameters.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] 1、 the present application is implemented by two-dimensional scanning galvanometer system on the workpiece surface in X-Y plane Precision path planning and optimization, at the same time, this technology cooperates with the rotating speed of C-axis, realizes the workpiece surface in circumferential direction to get uniform and efficient processing.

[0036] 2、The synergistic mechanism provided by the application can effectively inhibit the periodic fluctuation problem caused by the change of the laser spot pulse lap joint rate in the rotating machining process, thereby successfully realizing high-precision contour machining without waviness, and greatly improving the quality level of the machined surface.

[0037] 3、The application realizes high-precision and waviness-free machining of various shaped workpieces by precisely controlling the workpiece rotating speed, optimizing the machining path of the scanning galvanometer, and combining the high degree of freedom of the five-dimensional precision motion platform.

[0038] 4、The method is not only suitable for micro-nano machining of conventional materials, but also particularly suitable for manufacturing of optical elements and precision mechanical parts with extremely high surface quality requirements, and has wide application prospect and significant technical advantages.

[0039] Other beneficial effects of the application will be described in the specific embodiments by introducing specific technical features and technical solutions, and those skilled in the art should be able to understand the beneficial technical effects brought by the technical features and technical solutions through the introduction of the technical features and technical solutions. BRIEF DESCRIPTION OF DRAWINGS

[0040] Other features, objects and advantages of the application will become more apparent through reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings:

[0041] Figure 1 It is a schematic diagram of the application based on the galvanometer path optimization waviness-free femtosecond laser machining device.

[0042] Figure 2 It is a scanning path I machining schematic diagram in the embodiment of the application, and the long strip is along the Y direction.

[0043] Figure 3 It is a scanning path II machining schematic diagram in the embodiment of the application, and the long strip is along the X direction.

[0044] Figure 4 It is a scanning galvanometer path I machining result diagram in the embodiment of the application.

[0045] Figure 5 It is a scanning galvanometer path II machining result diagram in the embodiment of the application.

[0046] Figure 6 It is a method flowchart of the application.

[0047] Explanation of reference signs:

[0048] Femtosecond laser 1 Machining workpiece 8

[0049] Beam expander 2 Special fixture 9

[0050] Attenuator 3 Rotating C shaft 10

[0051] mirror 4 support frame 11

[0052] two-dimensional scanning galvanometer 5 rotation A axis 12

[0053] Z axis 6 Y axis 13

[0054] F-θ field mirror 7 X axis 14 DETAILED DESCRIPTION

[0055] The application will be described in detail below with specific embodiments. The following examples will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the application. These are within the scope of protection of the application.

[0056] Reference Figure 1 As shown, a ripple-free femtosecond laser processing device based on galvanometer path optimization includes:

[0057] femtosecond laser 1, beam expander 2, attenuator 3, mirror 4, two-dimensional scanning galvanometer 5, Z axis 6, F-θ field mirror 7, processing workpiece 8, special fixture 9, rotation C axis 10, support frame 11, rotation A axis 12, Y axis 13, X axis 14;

[0058] The femtosecond laser 1 is used to generate an ultrashort pulse laser beam propagating along a predetermined path; the wavelength of the laser beam is 1030 nm, the beam quality M 2 <1.2, pulse width 290 fs, maximum energy of single pulse 400 μJ, adjustable repetition frequency of 60 Hz-1000 kHz.

[0059] First, through the beam expander 2, the beam diameter is expanded, the divergence angle is controlled, the transmission efficiency is optimized, and the focusing performance is maintained during long-distance transmission; then enter the attenuator 3 to reduce the energy intensity of the laser beam; then enter the mirror 4 to change the propagation direction of the laser beam; then enter the two-dimensional scanning galvanometer 5 to realize fast and accurate adjustment of the direction and focal length of the laser beam; finally, enter the F-θ field mirror 7 to correct the nonlinear relationship of beam deflection, realize linear scanning and accurate focusing of the laser beam.

[0060] The two-dimensional scanning galvanometer 5 is fixed on the Z axis 6 to adjust the focusing of the laser spot diameter on the surface of the processing workpiece 8; the two-dimensional scanning galvanometer 5 adopts a strip-shaped laser reciprocating scanning mode in the X-Y plane, and the adaptive C-axis rotation speed is not more than 1.0 rpm.

[0061] After the laser spot is focused, the two-dimensional scanning galvanometer 5 is responsible for controlling the planning of the scanning path of the laser focal point in the X-Y plane on the surface of the processing workpiece 8.

[0062] The workpiece 8 is fixed on a special fixture 9, which is connected to a rotating C-axis 10. The rotation of the rotating C-axis 10 drives the special fixture 9 and the workpiece 8 to rotate, thereby achieving circumferential machining of the surface of the workpiece 8. The rotating C-axis 10 is connected to the A-axis 12, Y-axis 13, and X-axis 14 of the motion table via a support frame 11. The special fixture 9 is made of aluminum alloy. The maximum speed of the rotating C-axis 10 is 600 rpm, the maximum load is 10 kg, and the repeatability is 3.

[0063] The reflector is made of silver-plated or aluminum-plated glass or quartz; the beam expander 2 is made of optical glass or quartz; the attenuator 3 is made of neutral density filter or variable attenuator; it includes reflectors 4 in both X-axis and Y-axis directions, galvanometer motor and drive controller; the F-θ field lens 7 is made of fused silica with a focal length between 60mm and 100mm.

[0064] This invention utilizes a two-dimensional scanning galvanometer system to perform precise path planning and optimization on the workpiece surface in the XY plane. Simultaneously, this technology, in conjunction with an adapted C-axis rotation speed, enables uniform and efficient processing of the workpiece surface in the circumferential direction. This collaborative mechanism effectively suppresses the periodic fluctuations caused by changes in the laser spot pulse overlap rate during rotary processing, thereby successfully achieving high-precision contour processing without waviness and greatly improving the quality level of the processed surface.

[0065] Example 1

[0066] like Figure 1 As shown, this embodiment illustrates a ripple-free femtosecond laser processing apparatus based on galvanometer path optimization. It includes: a femtosecond laser 1 for providing the laser beam, a laser optical path transmission system, a two-dimensional scanning galvanometer system for laser path planning, a workpiece-specific fixture 9, and an XYZAC five-dimensional precision motion platform. The laser beam generated by the femtosecond laser 1 is transmitted, expanded, combined / coupled, attenuated, and monitored through a laser optical path transmission and focusing module. After passing through the two-dimensional scanning galvanometer 5, the scanning beam is focused onto the workpiece surface by an F-θ field mirror 7, achieving linear scanning of the laser beam.

[0067] The femtosecond processing system includes: a femtosecond laser 1, a beam expander 2, an attenuator 3, a reflector 4, a two-dimensional scanning galvanometer 5, a Z-axis 6, an F-θ field mirror 7, a workpiece 8, a special fixture 9, a rotating C-axis 10, a support frame 11, an A-axis 12, a Y-axis 13, and an X-axis 14.

[0068] The working principle is as follows:

[0069] The femtosecond laser 1 as a core component is used to generate an ultrashort pulse laser beam propagating along a preset path. First, the laser beam passes through the beam expander 2, which can effectively control the divergence angle of the light beam, enlarge the light beam diameter, optimize the laser transmission efficiency, and ensure the focusing performance of long-distance transmission of the laser; then enters the attenuator 3, which is used to reduce the energy intensity of the laser to adapt to the processing requirements of the workpiece material on the laser power; then enters the mirror 4, which changes the propagation direction of the laser beam; then enters the two-dimensional scanning galvanometer 5, which is fixed on the Z axis 6, and the focusing position of the laser spot on the surface of the workpiece 8 is accurately controlled by adjusting the position of the Z axis 6; after the laser spot is focused on the surface of the workpiece 8 by the F-θ field mirror 7, the scanning path in the X-Y plane is planned and optimized by the two-dimensional scanning galvanometer.

[0070] The workpiece 8 is fixed on the special fixture 9, and the special fixture 9 is connected with the rotary C-axis 10 turntable. By rotating the rotary C-axis 10, the special fixture 9 and the workpiece 8 can be rotated together, so that the circumferential processing of the surface of the workpiece 8 is realized.

[0071] The rotary C-axis 10 is connected with the motion table A-axis 12, Y-axis 13 and X-axis 14 through the support frame 11. The multi-axis motion control design enables the workpiece 8 to move and position accurately in multi-dimensional space, further improving the flexibility of the processing.

[0072] The material properties of each component:

[0073] The mirrors, attenuators 3, beam expanders 2, two-dimensional scanning galvanometers 5, F-θ field mirrors 7, etc. in the femtosecond laser processing system are usually customized according to system requirements. Among them, the mirrors commonly used include silver or aluminum coated glass or quartz, which need to have high-precision optical surfaces, good thermal stability, and be able to resist vibration and impact to ensure the collimation of the beam transmission; the attenuator 3 generally uses neutral density filter or variable attenuator, which needs to have good spectral transmittance, ability to prevent thermal deformation and high wear-resistant optical surface; the two-dimensional scanning galvanometer 5 includes X and Y two-direction mirrors 4, galvanometer motor and drive controller, etc.; at the same time, the F-θ field mirror 7 is usually made of optical glass or special materials, which has high light transmittance, excellent wear resistance and thermal stability, and maintains high-precision focusing performance.

[0074] The workpiece special fixture 9 is made of aluminum alloy material, which can significantly reduce the overall weight of the fixture due to its lightweight characteristics, which helps to reduce the rotational inertia of the fixture rotating with the C-axis, effectively improving the dynamic performance of the system.

[0075] High-precision laser beam wavelength 1030nm, beam quality M 2<1.2, pulse width 290fs, single pulse maximum energy 400uJ, adjustable repetition frequency of 60Hz-1000kHz.

[0076] The maximum rotating speed of the C-axis 10 is 600rpm, the maximum load is 10kg, and the repeat positioning accuracy is 3".

[0077] The focal length of the F-Theta field mirror 7 is between 60mm-100mm.

[0078] The two-dimensional scanning mirror 5 uses a strip-shaped laser reciprocating scanning mode in the X-Y plane, and the adapted C-axis rotating speed is not more than 1.0rpm.

[0079] The present application realizes high-precision and ripple-free machining of various shaped workpieces by precisely controlling the rotating speed of the workpiece and optimizing the machining path of the scanning mirror, combined with the high degree of freedom of the five-dimensional precision motion platform; it is not only suitable for micro-nano machining of conventional materials, but also particularly suitable for manufacturing optical elements and precision mechanical parts with extremely high surface quality requirements, and has wide application prospect and significant technical advantages.

[0080] Example 2

[0081] Referring to Figure 6 The present embodiment discloses a ripple-free femtosecond laser machining method based on mirror path optimization, comprising the following steps:

[0082] Step 1: connecting a special fixture 9 with a rotating C-axis 10;

[0083] Step 2: clamping the machining workpiece 8 on the special fixture 9;

[0084] Step 3: the laser beam generated by the femtosecond laser 1 is irradiated on the workpiece machining surface after passing through the two-dimensional scanning mirror 5 and the field mirror focusing;

[0085] Step 4: controlling the machining path of the laser focal point in the workpiece plane by the two-dimensional scanning mirror 5, realizing the machining of the circumferential direction of the workpiece surface in cooperation with the C-axis rotating speed, and realizing high-surface-quality laser machining by optimizing the laser pulse energy machining process parameters.

[0086] As Figure 2The diagram illustrates scanning path I of the processing implemented by the processing apparatus and method described in the above embodiments of the present invention. The laser spot begins processing from point A, first scanning along the -X direction (interval of 5 μm), then along the -Y direction in a long strip, then again along the -X direction (interval of 10 μm), and then again along the Y direction in a long strip, periodically scanning (scanning direction -X→-Y→-X→Y→-X) to point B; then from point B, it first scans along the X direction (interval of 5 μm), then along the Y direction in a long strip, then again along the X direction (interval of 10 μm), and then again along the -Y direction in a long strip, periodically scanning (scanning direction X→Y→X→-Y→X) back to point A. While the galvanometer is scanning back and forth, the C-axis rotates clockwise at a constant speed not exceeding 1.0 rpm.

[0087] like Figure 3 As shown in the diagram, this embodiment of the invention implements a scanning path I processing using the processing apparatus and method described in the above embodiments. The laser spot starts processing from point A, first scanning along the -Y direction (interval of 5μm), then scanning in a long strip along the -X direction, then scanning again along the -Y direction (interval of 10μm), then scanning again in a long strip along the X direction, periodically (scanning direction -Y→-X→-Y→X→-Y) to point B; then from point B, first scanning along the X direction (interval of 5μm), then scanning in a long strip along the Y direction, then scanning again along the X direction (interval of 10μm), then scanning again in a long strip along the -Y direction, periodically (scanning direction Y→-X→Y→-X→Y) back to point A. While the galvanometer is scanning back and forth, the C-axis rotates clockwise at a constant speed not exceeding 1.0 rpm.

[0088] like Figure 4 As shown, the scanning path I processing result is implemented by the processing device and processing method described in the above embodiments of the present invention. The workpiece surface has an "M" wavy profile.

[0089] like Figure 5 As shown, this is the result of scanning path II processing implemented by the processing device and processing method described in the above embodiments of the present invention. The workpiece surface contour is flat and smooth.

[0090] Compared with the prior art, the embodiments of the present invention implement a strip laser reciprocating scanning process path through a two-dimensional scanning galvanometer. At the same time, this technology, in conjunction with a C-axis clockwise uniform rotation speed of no more than 1.0 rpm, ensures that the workpiece surface is uniformly and efficiently processed in the circumferential direction, and can achieve high-precision laser processing with no waviness on the workpiece surface.

[0091] Those skilled in the art know that, in addition to implementing the system provided by the present application and each device, module and unit thereof in the form of pure computer readable program code, the system provided by the present application and each device, module and unit thereof can also be implemented in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers and embedded microcontrollers, etc. by logically programming the method steps to achieve the same functions. Therefore, the system provided by the present application and each device, module and unit thereof can be considered as a hardware component, and the devices, modules and units included therein for achieving various functions can also be considered as structures within the hardware component; the devices, modules and units for achieving various functions can also be considered as both software modules implementing methods and structures within hardware components.

[0092] The specific embodiments of the present application are described above. It needs to be understood that the present application is not limited to the specific embodiments described above, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be combined with each other in any manner without conflict.

Claims

1. A mirror-based path-optimized ripple-free femtosecond laser processing device, characterized in that, The application relates to a femtosecond laser machining device. The femtosecond laser (1) is used for generating an ultrashort pulse laser beam which propagates along a preset path; the preset path comprises making the ultrashort pulse laser beam pass through a beam expander (2), an attenuator (3), a reflector (4), a two-dimensional scanning galvanometer (5) and an F-theta field lens (7) in sequence. The beam expander (2) is used for expanding the diameter of the laser beam, controlling the divergence angle, optimizing the transmission efficiency and maintaining the focusing performance of the laser beam during transmission at a preset distance. The attenuator (3) is used for reducing the energy intensity of the laser beam. The reflector (4) is used for changing the propagation direction of the laser beam. The two-dimensional scanning galvanometer (5) is used for adjusting the direction and focal length of the laser beam. The F-theta field lens (7) is used for correcting the nonlinear relationship of laser beam deflection. The application further relates to a Z-axis (6), a machining workpiece (8), a special fixture (9), a rotating C-axis (10), a support frame (11), a rotating A-axis (12), a Y-axis (13) and an X-axis (14). The two-dimensional scanning galvanometer (5) is fixed on the Z-axis (6) and used for adjusting the focusing of the laser spot diameter on the surface of the machining workpiece (8); after the laser spot is focused, the two-dimensional scanning galvanometer (5) controls the laser focal point to scan the path planned in the X-Y plane of the surface of the machining workpiece (8). The machining workpiece (8) is fixed on the special fixture (9). The special fixture (9) is connected with the rotating C-axis (10). The rotating C-axis (10) is connected with the motion table A-axis (12), the Y-axis (13) and the X-axis (14) through the support frame (11). The maximum rotating speed of the rotating C-axis (10) is 600 rpm, the maximum load is 10 kg and the repeat positioning accuracy is 3''. The focal length of the F-theta field lens (7) is between 60 mm and 100 mm. The femtosecond laser (1) generates a laser beam with a wavelength of 1030 nm, a beam quality M 2 <1.2, a laser beam of ultrashort pulses with a pulse width of 290 fs, a maximum energy of a single pulse of 400 μJ, and an adjustable repetition frequency of 60 Hz~1000 kHz; The two-dimensional scanning galvanometer (5) adopts a strip type laser reciprocating scanning mode in the X-Y plane, and the rotating speed of the adaptive rotating C-axis (10) is not higher than 1.0 rpm. The rotating C-axis (10) is rotated to drive the special fixture (9) and the machining workpiece (8) to rotate, so that the machining workpiece (8) is machined along the circumferential direction. The material of the reflector (4) comprises silver-plated or aluminum-plated glass or quartz; the material of the beam expander (2) comprises optical glass or quartz; the attenuator (3) comprises a neutral density filter or a variable attenuator; and the material of the F-theta field lens (7) comprises fused quartz.

2. The no-ripple femtosecond laser machining device based on path optimization of galvanometer according to claim 1, wherein, The special fixture (9) is made of aluminum alloy.

3. The no-ripple femtosecond laser machining device based on path optimization of galvanometer according to claim 1, characterized in that, The application further relates to a machining method.

4. The no-ripple femtosecond laser machining device based on path optimization of galvanometer according to claim 1, characterized in that, Step S1: connecting the special fixture (9) with the rotating C-axis (10); 5. A method for ripple-free femtosecond laser processing based on mirror path optimization, using the ripple-free femtosecond laser processing device based on mirror path optimization according to any one of claims 1-4, characterized in that, Step S2: clamping the machining workpiece (8) on the special fixture (9); Step S3: making the laser beam generated by the femtosecond laser (1) irradiate on the surface of the machining workpiece (8) after passing through the two-dimensional scanning galvanometer (5) and the field lens; Step S4: controlling the laser focal point on the machining path in the plane of the machining workpiece (8) through the two-dimensional scanning galvanometer (5) and machining the workpiece surface along the circumferential direction in cooperation with the rotating C-axis (10). ​ ​ Step S5: further optimizing the machining process by optimizing the laser pulse energy machining process parameters.

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