Laser rotary cutting precision machining system and method for micropores with large depth-diameter ratio

Abstract

According to the large-depth-diameter-ratio micropore laser rotary-cutting precision machining system and method, light beam self-rotation and light beam scanning are achieved through a compact rotating assembly integrating a Dove prism and double reflectors, the off-axis angle and the off-axis amount are precisely regulated and controlled through deflection and movement of the reflectors, light beams are subjected to off-axis focusing through a focusing assembly, and the precision of laser rotary-cutting precision machining is achieved. Finally, a light path focusing mode of first converging and then off-axis focusing is formed, large-depth-diameter-ratio micropore machining is achieved, the aperture range is dozens of micrometers to several millimeters, and the maximum depth-diameter ratio can reach 15: 1 or above; the device is compact in structure, a complex adjusting system is not needed, the control mode is simple, high rotating speed can be achieved, ultra-short pulse time domain broadening is reduced through the double-reflector system, and machining of hole patterns such as steep straight holes and taper holes can be achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ultrafast laser processing, and particularly relates to a large-depth-diameter-ratio micro-hole laser rotary cutting precision machining system and method. BACKGROUND

[0002] Large-depth-diameter-ratio micro-holes have broad applications in the fields of aerospace engine blades, semiconductor functional devices, automobile engines, micro-nano optical devices, etc., and are important structural units of these components. The development trend of the machining requirements is small aperture, large depth-diameter ratio, and high precision. Current micro-hole machining technologies mainly include electric spark, electro-hydraulic beam, mechanical machining, and laser machining. Among them, the focused light field generated by ultrafast laser can directly ionize the material into plasma when acting on the material, which is regarded as a "cold machining" method without material selectivity. Ultrafast laser rotary cutting machining is a new micro-hole machining method, which has the characteristics of high machining precision, can realize machining without thermal effect and recast layer, and can realize machining of different rotary body hole types such as steep hole and taper hole, and the depth-diameter ratio can reach more than 15. In the future development trend of precision micro-hole machining technology, ultrafast laser rotary cutting machining is expected to become the mainstream technology.

[0003] Current ultrafast laser rotary cutting machining method is realized by rotating optical wedges and dove prisms. The basic principle is to realize spiral scanning of the machining laser beam by high-speed rotation of the optical wedges and refraction and deflection of the optical devices. The self-rotation of the light beam is realized by rotating the dove prism, and finally the off-axis focusing of the light beam is realized by the focusing lens, forming a light path focusing mode of converging and then off-axis focusing, avoiding the blocking of the machining hole wall, thereby realizing the machining of large-depth-diameter-ratio micro-holes. This machining method is also called rotary cutting punching. On this basis, different rotary cutting punching schemes such as double optical wedge, triple optical wedge, and quadruple optical wedge have been developed. In addition, there are rotary cutting punching methods based on rotary cylindrical lens rotary scanning device, three-reflection system, four-reflection system, parallel flat plate scanning head, and galvanometer combined with 4f optical system.

[0004] The current machining method based on the rotation of optical wedges has the following problems: first, the structure is complex, and multiple optical components such as optical wedges are needed to regulate the light path, and the optical components need to rotate at high speed around the optical axis to realize the machining of rotary bodies. The machining depth-diameter ratio and hole diameter are controlled by adjusting the distance between the optical wedges. Multiple element rotation and axial movement require multiple matching motors and other components. The overall adjustment module is large in size and heavy in weight, and has high requirements for the positioning accuracy of the rotary mechanical system, and the overall cost is high. Second, the scanning speed is slow, and the complex structure of the mirror group will affect the rotation speed of the mirror group, limiting the maximum laser power, thereby affecting the micro-hole machining efficiency. Third, the machining precision is limited. For the machining of precision holes of several hundred microns, the small shaft jump of the rotary shaft will cause large deviation in machining, and the shaft jump of the optical wedge rotating component is difficult to control due to its large size and heavy weight.

[0005] Spinning and scanning devices based on three- or four-reflection systems require precise synchronous control of multiple mirrors and complex algorithms, making them difficult to implement. Furthermore, the overall optical path is relatively long, and even a slight deviation in the optical path can lead to processing errors. Spinning and scanning processing methods based on rotating cylindrical lenses and galvanometers combined with a 4f optical system require the use of multiple transmissive optical lenses, which broadens the time domain of ultrashort pulses, reduces pulse time domain contrast, and affects the peak power of the processing. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a precision machining system and method for laser rotary cutting of micro-holes with large aspect ratios. By adjusting the tilt and movement of the internal mirror of the rotating assembly, beams with different off-axis angles and amounts can enter the focusing assembly, thereby enabling the machining of micro-holes with different apertures and aspect ratios on the sample.

[0007] A high aspect ratio micro-hole laser rotary cutting precision machining system includes a coaxial rotating component and a focusing component;

[0008] During the micro-hole fabrication process, the sample to be processed gradually moves towards the rotating component along the rotation axis. At the same time, the rotating component rotates around the rotation axis to drive the coaxially incident laser beam to rotate. The off-axis angle and / or off-axis amount of the laser beam as it exits the rotating component are gradually adjusted so that the ablation trajectory of the laser beam on the surface of the sample to be processed is a series of concentric rings, thus realizing micro-hole fabrication. Among them, the larger the off-axis angle, the larger the diameter of the concentric rings; when the off-axis amount is greater than or equal to the laser beam radius, the larger the off-axis amount, the smaller the depth-to-diameter ratio of the microhole.

[0009] Furthermore, the rotating assembly includes a synchronously rotating Dowell prism, a first reflector, and a second reflector; wherein the incident directions of the Dowell prism, the first reflector, and the laser beam are all coaxial with the rotation axis, and the second reflector is installed opposite to the first reflector;

[0010] The laser beam is incident on the focusing component sequentially through the Dowell prism, the first reflector, and the second reflector. The Dowell prism is used to rotate the laser beam around the optical axis by rotating itself. The first reflector is used to fold the self-rotated laser beam by 90°. The second reflector is used to fold the laser beam a second time after the first fold. The laser beam after the second fold is then incident on the focusing component.

[0011] Furthermore, the direction of the rotation axis is taken as the Y-axis direction, the horizontal direction as the X-axis direction, and the vertical direction as the Z-axis direction;

[0012] The first reflector has an angle of 45° with the Y-axis; the second reflector has an angle of 45°±5° with the Y-axis. While the second reflector rotates synchronously with the Dowell prism and the first reflector, it can also rotate in a direction perpendicular to the X-axis and move in the Z-axis direction. By adjusting the angle between the second reflector and the Y-axis, laser beams with different off-axis angles can enter the focusing assembly, thereby realizing the processing of micro-holes with different apertures on the sample. By adjusting the displacement of the second reflector in the Z-axis direction, laser beams with different off-axis amounts can enter the focusing assembly, thereby realizing the processing of micro-holes with different depth-to-diameter ratios on the sample.

[0013] Furthermore, as the sample to be processed gradually moves at a constant speed towards the rotating component along the rotation axis, the direction of the change in the off-axis angle is adjusted to achieve the processing of micropores of different hole types on the sample.

[0014] If the off-axis angle remains constant, a steep hole can be machined on the sample.

[0015] If the off-axis angle gradually decreases, a positive conical hole can be machined on the sample;

[0016] If the off-axis angle gradually increases, the inverted conical hole can be machined on the sample.

[0017] Furthermore, by adjusting the off-axis amount, the angle at which the laser beam is incident on the sample through the focusing component can be changed, thereby achieving the processing of micro-holes with different depth-to-diameter ratios on the sample. Specifically, if the off-axis amount is equal to the laser beam radius, the angle at which the outer edge of the laser beam is incident on the sample is 90°, resulting in the largest depth-to-diameter ratio of the processed micro-hole. Meanwhile, as the off-axis amount continues to increase from the laser beam radius, the larger the off-axis amount, the smaller the depth-to-diameter ratio of the processed micro-hole.

[0018] Furthermore, the second reflector is a fast-reflecting mirror or a scanning galvanometer, and its rapid rotation is achieved by a voice coil motor or piezoelectric ceramic.

[0019] Furthermore, a precision machining method for laser rotary cutting of micro-holes with a large aspect ratio includes:

[0020] Step 1: Determine the system parameters based on the required aperture shape and the required depth-to-diameter ratio. The system parameters include: the off-axis angle, the amount of off-axis, and the direction of change of the off-axis angle when the laser beam exits from the rotating component.

[0021] Step 2: After adjusting the initial pose of the rotating component and the focusing component according to the set system parameters, start the rotating component. At the same time, gradually move the sample to be processed along the rotation axis of the rotating component towards the rotating component, so that the laser beam ablates the sample to be processed layer by layer to obtain the micropore with the required hole shape and the required depth-to-diameter ratio.

[0022] Furthermore, when the laser beam ablates the sample to be processed layer by layer:

[0023] If the required hole shape is a steep hole, the maximum off-axis angle used for each layer ablation remains unchanged, and during the ablation process of each layer, the off-axis angle increases from zero to the maximum off-axis angle to achieve ablation scanning from the hole center to the hole edge and uniformly remove one layer of sample.

[0024] If the required hole shape is a positive conical hole, the maximum off-axis angle used for ablation of each layer gradually decreases from the surface to the inside, and during the ablation process of each layer, the off-axis angle increases from zero to the maximum off-axis angle used in this layer, so as to achieve ablation scanning from the hole center to the hole edge and uniformly remove one layer of sample.

[0025] If the required hole shape is an inverted conical hole, the maximum off-axis angle used for ablation of each layer gradually increases from the surface to the inside. During the ablation process of each layer, the off-axis angle increases from zero to the maximum off-axis angle used for that layer, so as to achieve ablation scanning from the hole center to the hole edge and uniformly remove one layer of sample.

[0026] Furthermore, if the required aspect ratio is the maximum achievable aspect ratio, then the off-axis amount is set to the radius of the laser beam.

[0027] Furthermore, as the off-axis amount continues to increase from the laser beam radius, the greater the off-axis amount, the smaller the depth-to-diameter ratio of the processed micro-hole.

[0028] Beneficial effects:

[0029] 1. This invention provides a high aspect ratio micro-hole laser rotary cutting precision machining system. It achieves beam self-rotation and beam scanning through a compact rotating assembly integrating a Dowell prism and dual reflectors. The off-axis angle and amount are precisely controlled by the deflection and movement of the reflectors. The beam is then focused off-axis by a focusing assembly, ultimately forming a focusing optical path that first converges and then focuses off-axis, enabling the machining of micro-holes with a large aspect ratio, ranging from tens of micrometers to several millimeters in diameter, with a maximum aspect ratio exceeding 15:1. This invention features a compact structure, eliminates the need for complex adjustment systems, and simplifies control. It achieves high rotational speeds, and the dual reflector system reduces the time-domain broadening of ultrashort pulses, enabling the machining of steep holes, tapered holes, and other hole types.

[0030] 2. This invention provides a precision machining method for laser rotary cutting of micro-holes with large aspect ratio. By controlling the sample to move in a stepping motion along the rotation axis and simultaneously controlling the off-axis angle and off-axis amount to change the diameter and angle of the laser beam incident on the sample through the focusing component, the machining of hole types such as steep holes and conical holes can be realized, meeting the high-precision machining requirements of micro-holes with large aspect ratio in aerospace, semiconductor and other fields. Attached Figure Description

[0031] Figure 1 A schematic diagram of a high aspect ratio micro-hole laser rotary cutting precision machining system provided by the present invention;

[0032] Figure 2 These are two states of the rotating component provided by the present invention when it rotates at high speed around the rotation axis;

[0033] Figure 3 A schematic diagram of the scanning trajectory formed by the rotating component of the present invention rotating 360°.

[0034] Figure 4 This invention provides different hole diameter machining implementation methods;

[0035] Figure 5 A schematic diagram showing the maximum achievable machining depth-to-diameter ratio corresponding to different off-axis amounts provided by the present invention;

[0036] Figure 6 This is a schematic diagram of the machining of steep holes provided by the present invention;

[0037] Figure 7 This is a schematic diagram of the machining of a conical hole provided by the present invention;

[0038] Figure 8 This is a schematic diagram of the machining of the inverted conical hole provided by the present invention. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0040] To achieve precision machining of micro-holes with large aspect ratios, this invention provides a laser rotary cutting precision machining system for micro-holes with large aspect ratios, comprising a coaxial rotating assembly and a focusing assembly;

[0041] During micro-hole fabrication, the sample to be processed gradually moves towards the rotating assembly along its rotation axis. Simultaneously, the rotating assembly rotates around its axis, causing the coaxially incident laser beam to rotate. The off-axis angle and / or amount of the laser beam exiting the rotating assembly are gradually adjusted, resulting in a series of concentric rings on the sample surface, thus achieving micro-hole fabrication. In other words, the rotating assembly rotates at high speed around its axis, driving the laser beam to rotate and achieving circular motion. A larger off-axis angle results in a larger diameter of the concentric rings. When the off-axis amount is greater than or equal to the laser beam radius, a larger off-axis amount results in a smaller depth-to-diameter ratio for the micro-hole.

[0042] Specifically, such as Figure 1 As shown, the rotating assembly includes a synchronously rotating Dowell prism, a first reflector, and a second reflector; wherein the incident directions of the Dowell prism, the first reflector, and the laser beam are all coaxial with the rotation axis, and the second reflector is installed opposite to the first reflector;

[0043] The laser beam is sequentially incident on the focusing component via the Dowell prism, the first reflector, and the second reflector. The Dowell prism is used to rotate the laser beam around the optical axis by rotating itself, thereby increasing the roundness of the processed micro-hole. The first reflector is used to fold the self-rotated laser beam by 90°. The second reflector is used to fold the laser beam a second time after the first fold, and the laser beam after the second fold is then incident on the focusing component.

[0044] Optionally, the second reflector can be a fast reflector, a scanning galvanometer, or other components. The tilt angle of the reflector can be precisely and quickly adjusted by a voice coil motor, piezoelectric ceramics, etc. The focusing component is a lens or lens group with positive optical power, which focuses the laser beam from the rotating component onto the sample surface. When the rotating component rotates around the rotation axis, the scanning trajectory on the sample is a circle.

[0045] In this invention, the direction of the rotation axis is defined as the Y-axis, the horizontal direction as the X-axis, and the vertical direction as the Z-axis.

[0046] The first reflector has an angle of 45° with the Y-axis; the second reflector has an angle of 45°±5° with the Y-axis. While the second reflector rotates synchronously with the Dowell prism and the first reflector, it can also rotate in a direction perpendicular to the X-axis and move in the Z-axis direction. By adjusting the angle between the second reflector and the Y-axis, laser beams with different off-axis angles can enter the focusing assembly, thereby realizing the processing of micro-holes with different apertures on the sample. By adjusting the displacement of the second reflector in the Z-axis direction, laser beams with different off-axis amounts can enter the focusing assembly, thereby realizing the processing of micro-holes with different depth-to-diameter ratios on the sample.

[0047] In other words, the off-axis angle determines the aperture, and the amount of off-axis deviation determines the depth-to-diameter ratio. For example... Figure 2 The diagram shows two states of the rotating component when it rotates at high speed around the rotation axis to its uppermost and lowermost positions. This demonstrates that the present invention, through the high-speed rotation of the rotating component, can form a focused beam of light, enabling the fabrication of circular holes on a sample. Figure 3 The image shows the scanning trajectory formed by the rotating component rotating 360° (sampling at 30° intervals).

[0048] For example, such as Figure 4 As shown, the focal length of the focusing component is f, the off-axis angle θ is the angle by which the incident beam deviates from the optical axis of the focusing component, the off-axis amount h is the height by which the center of the incident beam deviates from the optical axis of the focusing component, and the scanning diameter is the diameter D of the ring formed by the focused spot after the beam rotates 360° around the optical axis of the focusing component. According to the optical geometry of rays, D = 2 × f × tanθ. The scanning ring diameter D is directly proportional to the off-axis angle; the larger the off-axis angle, the larger the scanning diameter. The focal length of the focusing component is f = 100 mm, and the off-axis angle is 0° / 0.1° / 0.2°. Figure 4The rightmost part is an enlarged view of the middle dashed box, from which it can be seen that... Figure 4 The obtained scanning diameters are 0mm / 0.35mm / 0.7mm. During rotary cutting for hole making, the diameter to be processed must be fixed. According to the formula D=2×f×tanθ, the maximum processing angle θ can be determined. Then, by gradually increasing the off-axis angle, scanning is achieved from the hole center to the hole edge, uniformly removing a layer of material. This process is repeated continuously. Combined with the sample's stepping along the Y direction, material is removed layer by layer, achieving the processing of micro-holes.

[0049] It should be noted that the present invention can control the different off-axis amounts h of the laser beam relative to the rotation axis by adjusting the movement of the second reflecting mirror along the Z-axis, thereby changing the angle at which the laser beam is incident on the sample through the focusing component, and realizing the processing of micro-holes with different depth-to-diameter ratios on the sample; wherein, if the off-axis amount is equal to the laser beam radius, the angle at which the light rays from the outer edge of the laser beam are incident on the sample is 90°, and the processed micro-hole has the largest depth-to-diameter ratio; at the same time, as the off-axis amount continues to increase from the laser beam radius, the larger the off-axis amount, the smaller the processed micro-hole has the smaller the depth-to-diameter ratio.

[0050] A specific calculation example is as follows: The beam diameter is 10mm, and the focal length of the focusing component is f=150mm. Setting the off-axis distance h to 5mm and 10mm respectively, the maximum achievable machining depth-to-diameter ratios for the two off-axis distances are 15:1 and 11:1, respectively. Figure 5 As shown. The results show that when the off-axis distance is equal to the beam radius, Figure 5 In the magnified section of the dashed box, the angle between the upper edge of the laser beam when it is rotated to the top and the lower edge of the laser beam when it is rotated to the bottom, and the angle between them incident on the sample, is 90°. At this point, the maximum machining depth-to-diameter ratio can be achieved. As the off-axis amount continues to increase, the machining depth-to-diameter ratio decreases accordingly.

[0051] Furthermore, the present invention can also achieve beams entering the focusing component at different off-axis angles by adjusting the rotation of the second reflecting mirror. That is, by setting the off-axis angle, micropores of different hole types can be obtained. Specifically, when the sample to be processed gradually moves towards the rotating component at a constant speed along the rotation axis of the rotating component, the processing of micropores of different hole types on the sample can be achieved by adjusting the direction of the change of the off-axis angle.

[0052] If the off-axis angle remains constant, a steep hole can be machined on the sample.

[0053] If the off-axis angle gradually decreases, a positive conical hole can be machined on the sample;

[0054] If the off-axis angle gradually increases, the inverted conical hole can be machined on the sample.

[0055] Based on the above-mentioned high aspect ratio micro-hole laser rotary cutting precision machining system, the present invention also provides a high aspect ratio micro-hole laser rotary cutting precision machining method, including:

[0056] Step 1: Determine the system parameters based on the required aperture shape and the required depth-to-diameter ratio. The system parameters include: the off-axis angle, the amount of off-axis, and the direction of change of the off-axis angle when the laser beam exits from the rotating component.

[0057] Step 2: After adjusting the initial pose of the rotating component and the focusing component according to the set system parameters, start the rotating component. At the same time, the sample to be processed is gradually and uniformly moved towards the rotating component along the rotation axis, so that the laser beam ablates the sample to be processed layer by layer to obtain the micropore with the required hole shape and the required depth-to-diameter ratio.

[0058] Specifically, when the laser beam ablates the sample to be processed layer by layer:

[0059] If the required hole shape is a steep straight hole, such as Figure 6 As shown, during the uniform stepping motion of the sample along the Y direction, the maximum off-axis angle used for each layer ablation remains unchanged, that is, the maximum scanning diameter D remains unchanged. Moreover, during the ablation process of each layer, the off-axis angle increases from zero to the maximum off-axis angle, thereby achieving ablation scanning from the hole center to the hole edge and uniformly removing one layer of sample.

[0060] If the required hole shape is a positive conical hole, such as Figure 7 As shown, according to the formula D=2×f×tanθ, during the uniform stepping motion of the sample along the Y direction, the maximum off-axis angle used for ablation of each layer gradually decreases from the surface to the inside, that is, the maximum scanning diameter D corresponding to each layer is reduced. In addition, during the ablation of each layer, the off-axis angle increases from zero to the maximum off-axis angle used for this layer, so as to achieve ablation scanning from the hole center to the hole edge and uniformly remove one layer of sample.

[0061] If the required hole shape is an inverted conical hole, such as Figure 8 As shown, according to the formula D=2×f×tanθ, during the uniform stepping motion of the sample along the Y direction, the maximum off-axis angle used for ablation of each layer gradually increases from the surface to the inside, that is, the maximum scanning diameter D corresponding to each layer is increased. During the ablation of each layer, the off-axis angle increases from zero to the maximum off-axis angle used in this layer, so as to realize the ablation scanning from the hole center to the hole edge and uniformly remove a layer of sample.

[0062] If the required aspect ratio is the maximum achievable aspect ratio, then the off-axis amount is set to the radius of the laser beam; at the same time, as the off-axis amount continues to increase from the laser beam radius, the larger the off-axis amount, the smaller the aspect ratio of the processed micro-hole.

[0063] In summary, this invention proposes a high aspect ratio micro-hole laser rotary cutting precision machining system and method. The system has a compact structure and simple control, and the hole diameter covers tens of micrometers to several millimeters, with a maximum aspect ratio of 15:1 or more. It can realize the machining of hole types such as steep straight holes, positive conical holes, and inverted conical holes, meeting the high-precision machining needs of micro-holes with large aspect ratios in aerospace, semiconductor and other fields.

[0064] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A high aspect ratio micro-hole laser rotary cutting precision machining system, characterized in that, Including coaxial rotating components and focusing components; During the micro-hole fabrication process, the sample to be processed gradually moves towards the rotating component along the rotation axis. At the same time, the rotating component rotates around the rotation axis to drive the coaxially incident laser beam to rotate. The off-axis angle and / or off-axis amount of the laser beam as it exits the rotating component are gradually adjusted so that the ablation trajectory of the laser beam on the surface of the sample to be processed is a series of concentric rings, thus realizing micro-hole fabrication. Among them, the larger the off-axis angle, the larger the diameter of the concentric rings; when the off-axis amount is greater than or equal to the laser beam radius, the larger the off-axis amount, the smaller the depth-to-diameter ratio of the microhole.

2. The high aspect ratio micro-hole laser rotary cutting precision machining system as described in claim 1, characterized in that, The rotating assembly includes a synchronously rotating Dowell prism, a first reflector, and a second reflector; wherein the incident directions of the Dowell prism, the first reflector, and the laser beam are all coaxial with the rotation axis, and the second reflector is installed opposite to the first reflector. The laser beam is incident on the focusing component sequentially through the Dowell prism, the first reflector, and the second reflector. The Dowell prism is used to rotate the laser beam around the optical axis by rotating itself. The first reflector is used to fold the self-rotated laser beam by 90°. The second reflector is used to fold the laser beam a second time after the first fold. The laser beam after the second fold is then incident on the focusing component.

3. The high aspect ratio micro-hole laser rotary cutting precision machining system as described in claim 2, characterized in that, The direction of the rotation axis is taken as the Y-axis, the horizontal direction as the X-axis, and the vertical direction as the Z-axis. The first reflector has an angle of 45° with the Y-axis; the second reflector has an angle of 45°±5° with the Y-axis. While the second reflector rotates synchronously with the Dowell prism and the first reflector, it can also rotate in a direction perpendicular to the X-axis and move in the Z-axis direction. By adjusting the angle between the second reflector and the Y-axis, laser beams with different off-axis angles can enter the focusing assembly, thereby realizing the processing of micro-holes with different apertures on the sample. By adjusting the displacement of the second reflector in the Z-axis direction, laser beams with different off-axis amounts can enter the focusing assembly, thereby realizing the processing of micro-holes with different depth-to-diameter ratios on the sample.

4. The high aspect ratio micro-hole laser rotary cutting precision machining system as described in claim 3, characterized in that, As the sample to be processed gradually moves at a constant speed along the rotation axis of the rotating component, the direction of the change in the off-axis angle is adjusted to achieve the processing of micropores of different hole types on the sample. If the off-axis angle remains constant, a steep hole can be machined on the sample. If the off-axis angle gradually decreases, a positive conical hole can be machined on the sample; If the off-axis angle gradually increases, the inverted conical hole can be machined on the sample.

5. The high aspect ratio micro-hole laser rotary cutting precision machining system as described in claim 3, characterized in that, By adjusting the off-axis amount, the angle at which the laser beam is incident on the sample through the focusing component can be changed, thus enabling the processing of micro-holes with different depth-to-diameter ratios on the sample. Specifically, if the off-axis amount is equal to the laser beam radius, the angle at which the light rays from the outer edge of the laser beam are incident on the sample is 90°, resulting in the largest depth-to-diameter ratio of the processed micro-hole. Meanwhile, as the off-axis amount continues to increase from the laser beam radius, the larger the off-axis amount, the smaller the depth-to-diameter ratio of the processed micro-hole.

6. A high aspect ratio micro-hole laser rotary cutting precision machining system as described in any one of claims 2 to 5, characterized in that, The second reflector is a fast-reflecting mirror or a scanning galvanometer, and its rapid rotation is achieved by a voice coil motor or piezoelectric ceramic.

7. A method for precision machining of micro-holes with a large aspect ratio using laser rotary cutting based on the high aspect ratio micro-hole laser rotary cutting precision machining system according to claim 1, characterized in that, include: Step 1: Determine the system parameters based on the required aperture shape and the required depth-to-diameter ratio. The system parameters include: the off-axis angle, the amount of off-axis, and the direction of change of the off-axis angle when the laser beam exits from the rotating component. Step 2: After adjusting the initial pose of the rotating component and the focusing component according to the set system parameters, start the rotating component. At the same time, gradually move the sample to be processed along the rotation axis of the rotating component towards the rotating component, so that the laser beam ablates the sample to be processed layer by layer to obtain the micropore with the required hole shape and the required depth-to-diameter ratio.

8. The precision machining method for laser rotary cutting of micro-holes with a large aspect ratio as described in claim 7, characterized in that, When a laser beam ablates the sample to be processed layer by layer: If the required hole shape is a steep hole, the maximum off-axis angle used for each layer ablation remains unchanged, and during the ablation process of each layer, the off-axis angle increases from zero to the maximum off-axis angle to achieve ablation scanning from the hole center to the hole edge and uniformly remove one layer of sample. If the required hole shape is a positive conical hole, the maximum off-axis angle used for ablation of each layer gradually decreases from the surface to the inside, and during the ablation process of each layer, the off-axis angle increases from zero to the maximum off-axis angle used in this layer, so as to achieve ablation scanning from the hole center to the hole edge and uniformly remove one layer of sample. If the required hole shape is an inverted conical hole, the maximum off-axis angle used for ablation of each layer gradually increases from the surface to the inside. During the ablation process of each layer, the off-axis angle increases from zero to the maximum off-axis angle used for that layer, so as to achieve ablation scanning from the hole center to the hole edge and uniformly remove one layer of sample.

9. A precision machining method for laser rotary cutting of micro-holes with a large aspect ratio as described in claim 7 or 8, characterized in that, If the required aspect ratio is the maximum achievable aspect ratio, then the off-axis amount is set to the radius of the laser beam.

10. The precision machining method for laser rotary cutting of micro-holes with a large aspect ratio as described in claim 9, characterized in that, As the off-axis amount continues to increase from the laser beam radius, the greater the off-axis amount, the smaller the depth-to-diameter ratio of the processed micro-hole.

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