An ultrahigh-speed module application system based on cooperation of an acousto-optic deflector and a galvanometer

Abstract

The utility model provides a kind of super high-speed module application system based on acoustooptic deflector and galvanometer cooperative operation, to solve the defects of small scanning angle and slow response speed of prior art laser scanning system.The utility model mainly includes laser, half wave plate, first acoustooptic deflector, second acoustooptic deflector, acoustooptic deflector radio frequency drive, diaphragm, 4f system, first reflector, second reflector, galvanometer, focusing lens, processing plane, controller, XYZ motion platform and CCD camera in structure.The utility model is cooperated by acoustooptic deflector and galvanometer, both retain the wide-angle scanning capability of galvanometer, and also have the high-speed response characteristic of acoustooptic deflector, while the introduction of 4f optical system effectively solves the aberration problem, ensures scanning precision and spot quality.

Description

Technical Field

[0001] This utility model relates to the field of laser scanning processing technology, and in particular to an ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer. Background Technology

[0002] In the field of laser processing technology, traditional laser scanning systems mostly adopt galvanometer structures. Although they have advantages such as low cost and good stability, their mechanical inertia is large and their response speed is limited, making it difficult to meet the processing requirements of ultra-high speed and high precision.

[0003] With the emergence of a new direction in the field of high-speed laser scanning—acoustic-optic deflectors—which have advantages such as small minimum deflection angle, fast deflection speed, no mechanical inertia, and small size, they have become a new direction in the field of high-speed laser scanning. However, the small acousto-optic scanning angle caused by acousto-optic action limits their applicability in large-format processing.

[0004] Therefore, how to organically combine the acousto-optic deflector with the galvanometer system to leverage their respective advantages has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0005] To address the shortcomings of the prior art, this application provides an ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer. By coordinating the acousto-optic deflector and the galvanometer, the system retains the large-angle scanning capability of the galvanometer while possessing the high-speed response characteristics of the acousto-optic deflector. At the same time, the introduction of a 4f optical system effectively solves the aberration problem, ensuring scanning accuracy and spot quality.

[0006] The technical solution adopted in this utility model is as follows: An ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer includes: a laser, a half-wave plate, a first acousto-optic deflector, a second acousto-optic deflector, an acousto-optic deflector RF driver, a 4f system, a first mirror, a second mirror, a galvanometer, a focusing lens, a processing plane, a controller, an XYZ motion platform, and a CCD camera. The laser's light output direction is sequentially provided with a first acousto-optic deflector, a half-wave plate, and a second acousto-optic deflector; The radio frequency driver of the acousto-optic deflector is electrically connected to the first acousto-optic deflector and the second acousto-optic deflector. The second acousto-optic deflector is equipped with a 4f system and a first reflector in sequence along its light-emitting direction; A second reflector is provided in the reflected light path of the first reflector; A galvanometer is provided in the reflected light path of the second reflector; The galvanometer is provided with a focusing lens in the light-emitting direction, and the focusing lens is directly facing the processing plane; The machining plane is provided with an XYZ motion platform, which is configured to carry the workpiece being machined; The CCD camera is located on one side of the galvanometer and is configured to detect the position of the workpiece being processed. The controller is communicatively connected to the laser, galvanometer, acousto-optic deflector RF driver, XYZ motion platform, and CCD camera, and is configured to coordinate the collaborative operation of the various components.

[0007] Furthermore, the 4f system includes a first lens, an aperture stop, and a second lens, which are configured to receive the laser beam and perform beam expansion processing; The first lens is located in the light output path of the second acousto-optic deflector; the aperture is located on the back focal plane of the first lens and is configured to block zero-order diffraction light and allow first-order diffraction light to pass through; the second lens is used to expand the beam and guide it to the first reflector.

[0008] Furthermore, the surfaces of the first lens and the second lens are coated with an anti-reflection film, with an average reflectivity of less than 0.25%.

[0009] Furthermore, the galvanometer is a two-dimensional scanning galvanometer, including X-axis and Y-axis galvanometers.

[0010] Furthermore, the focusing lens is an F-theta lens with a focal length of 170mm, configured to form a focused spot with a diameter of 20μm on the processing plane.

[0011] Furthermore, the XYZ motion platform is equipped with a vacuum suction cup for fixing the workpiece.

[0012] Furthermore, it also includes a vacuum cleaner, disposed between the focusing lens and the processing plane, for absorbing dust generated during the processing.

[0013] Furthermore, the laser is a nanosecond laser, a picosecond laser, or a femtosecond laser.

[0014] The advantages of this utility model over the prior art are as follows: This invention, through the coordinated operation of an acousto-optic deflector and a galvanometer, combines the high-speed response of the acousto-optic deflector with the large-angle scanning advantage of the galvanometer, effectively solving the problem of balancing speed and accuracy in traditional laser processing systems. Furthermore, the introduction of the 4f system further optimizes the optical path quality, improving processing accuracy and efficiency.

[0015] This utility model has a reasonable structure, high control precision, and wide applicability, and can be widely used in high-end manufacturing fields such as precision machining, microelectronics, semiconductors, and medical equipment. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the two-dimensional acousto-optic deflector scanning structure in this utility model; Figure 3 This is a schematic diagram of the optical path structure of this utility model; Figure 4 This is a schematic diagram of the system control of this utility model.

[0017] The components include: 1. Laser; 2. First acousto-optic deflector; 3. Half-wave plate; 4. Second acousto-optic deflector; 5. 4f system; 6. First lens; 7. Aperture stop; 8. Second lens; 9. First mirror; 10. Second mirror; 11. Galvanometer; 12. Focusing lens; 13. Workpiece; 14. Machining plane; 15. XYZ motion platform; 16. CCD camera; 17. Acousto-optic deflector RF drive; 18. Vacuum cleaner; 19. Controller. Detailed Implementation

[0018] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0019] Preferred structural embodiment of this utility model: like Figures 1 to 4 As shown, the system includes a laser 1, which emits a laser beam that passes sequentially through a first acousto-optic deflector 2, a half-wave plate 3, and a second acousto-optic deflector 4. An acousto-optic deflector RF driver 17 controls the first and second acousto-optic deflectors 2 and 4. A 4f system 5 and a first reflector 9 are arranged sequentially on the light path emitted from the second acousto-optic deflector 4. A second reflector 10 is arranged on the reflected light path of the first reflector 9. A galvanometer 11 is arranged on the reflected light path of the second reflector 10. A focusing lens 12 is arranged on the light path emitted from the galvanometer 11, and the focusing lens 12 faces the workpiece 13 on the processing plane 14. A controller 19 is connected to the laser 1, galvanometer 11, XYZ motion platform 15, CCD camera 16, and acousto-optic deflector RF driver 17.

[0020] In one embodiment of this utility model, laser 1 emits a Gaussian or flat-top distributed laser beam; In one embodiment of this utility model, acousto-optic deflectors 2 and 4 are used to control the deflection angle of the laser beam. In one embodiment of this utility model, the half-wave plate 3 is used to convert a linearly polarized laser beam into a horizontally or vertically polarized laser beam. In one embodiment of this utility model, the 4f system 5 is composed of a first lens 6, an aperture 7, and a second lens 8, and is used to receive laser beams and perform beam expansion processing. In one embodiment of this invention, the surfaces of the first lens 6 and the second lens 8 are coated with an anti-reflection film (AR film), with an average reflectivity of <0.25%; In one embodiment of this utility model, the aperture 7 blocks the zeroth-order diffracted beam in the laser beam, allowing the first-order diffracted beam to pass through. In one embodiment of this utility model, the galvanometer 11 is used to receive the laser beam after it has been expanded by the 4f system 5; In one embodiment of this utility model, the focusing lens 12 is used to focus the laser beam emitted from the galvanometer 11 onto the workpiece 13 on the processing plane 14. In one embodiment of this utility model, the XYZ motion platform 15 supports the workpiece 13 and moves it to the laser processing area directly below the galvanometer 11; In one embodiment of this utility model, a CCD camera 16 is mounted on one side of the galvanometer 11 and connected to a controller 19 for detecting the position of the workpiece 13 being processed. In one embodiment of this utility model, the controller 19 is used to coordinate the operation of the laser 1, the first acousto-optic deflector 2, the second acousto-optic deflector 4, the galvanometer 11, the XYZ motion platform 15 and the CCD camera 16 according to preset instructions.

[0021] In one embodiment of this utility model, the laser wavelength of laser 1 is 355nm, the pulse repetition frequency is Fr=50kHz, and the average power is 2W.

[0022] In one embodiment of this utility model, the first acousto-optic deflector 2 and the second acousto-optic deflector 4 are quartz broadband acousto-optic deflectors with an aperture of 7mm, D=3.5mm, a quartz sound velocity of 5740m / s, and a working bandwidth of 130-210MHz with a diffraction efficiency ≥85%. The formula yields a deflection angle range of 8.040-12.988 mrad corresponding to the working bandwidth, and a scan angle range of α=4.9 mrad.

[0023] In one embodiment of this invention, the response speed of the acousto-optic deflector is determined by the time it takes for the sound wave to travel through the light beam; that is, the transit time. The maximum switching frequency of the acousto-optic deflector is... The maximum deflection speed is .

[0024] In one embodiment of this utility model, the magnification of the 4f system 5 is M=f2 / f1=1.33, wherein the focal length f1 of the first lens 6 is 75mm, 150mm, and 300mm, and the focal length f2 of the second lens 8 is 100mm, 200mm, and 400mm.

[0025] In one embodiment of this utility model, when the preset aperture of the micropore is 25 to 500 μm, the galvanometer 11 controls the laser beam to perform processing in a single-point multi-pulse scanning mode.

[0026] In one embodiment of this utility model, the focal length of the focusing lens 12 is 170mm.

[0027] In one embodiment of this invention, the control section of the device consists of a control board, an acousto-optic deflector RF driver 17, and a host computer. The control board outputs a 500kHz synchronization signal to the laser 1 and the acousto-optic deflector RF driver 17.

[0028] In one embodiment of this utility model, a vacuum suction cup is mounted on the XYZ motion platform 15 to fix the workpiece 13 to be processed.

[0029] In one embodiment of this utility model, a vacuum cleaner 18 is installed between the workpiece 13 being processed on the processing platform 14 and the focusing lens 12.

[0030] It should be noted that the processing materials used in the process are epoxy molding filler and traditional plain glass, Schottky glass, and alumina-based glass.

[0031] Example 1 of the application of this utility model: laser precision machining In precision laser machining, a laser beam emitted by a 355nm laser wavelength laser 1 is matched with the aperture of an acousto-optic deflector. The laser beam enters two orthogonally placed acousto-optic deflectors and is deflected by them. A half-wave plate 3 is placed between the first acousto-optic deflector 2 and the second acousto-optic deflector 4 to match the polarization direction of the beam with the acousto-optic deflector. The laser beam emitted from the second acousto-optic deflector 4 is expanded by a 4f system 5 consisting of a first lens 6, an aperture 7, and a second lens 8. Then, it is adjusted by a first reflecting mirror 9 and a second reflecting mirror 10 to be orthogonally incident on a galvanometer 11. The beam deflected by the galvanometer 11 is focused by a focusing lens 12 onto the workpiece 13 on the machining surface 14, and the final focused spot diameter on the workpiece 13 is 20 μm.

[0032] Example 2 of the application of this utility model: Laser linewidth processing Traditional methods require multiple scans of the galvanometer to broaden the laser linewidth, while this invention requires only a single scan. During galvanometer movement, an acousto-optic deflector rapidly deflects the laser pulse to both sides of the path, achieving laser linewidth broadening and significantly improving processing efficiency.

[0033] Laser 1 emits high-repetition-rate pulsed laser light. The laser beam passes sequentially through a first acousto-optic deflector 2 and a second acousto-optic deflector 4, achieving rapid deflection under the control of the acousto-optic deflector RF drive 17. A half-wave plate 3 is used to adjust the beam polarization direction to match the acousto-optic deflector. After deflection, the laser beam is expanded by the 4f system 5 and reflected by the first reflector 9 and the second reflector 10 to the galvanometer 11. The galvanometer 11 performs a single scan motion, while the acousto-optic deflector dynamically adjusts the laser deflection angle with a microsecond-level response speed, ensuring precise distribution of laser pulses on both sides of the scanning path. The focusing lens 12 focuses the laser beam onto the processing plane 14, forming a uniform pulse dot matrix on the surface of the workpiece 13, precisely generating the laser linewidth of the target width. The controller 19 synchronously adjusts the galvanometer scanning speed Vg and the laser pulse frequency Fr to achieve efficient and high-precision laser linewidth processing. The XYZ motion platform 15 carries the workpiece and works with the galvanometer 11 to complete the processing. The entire system achieves stable and repeatable processing results through parametric control.

[0034] Example 3 of the application of this utility model: laser linewidth processing of circles or arcs. After the laser pulse is emitted from laser 1, it first undergoes preliminary deflection adjustment by the first acousto-optic deflector 2, then its polarization direction is adjusted by the half-wave plate 3, and finally it enters the second acousto-optic deflector 4 for final angle correction. The acousto-optic deflector RF driver 17 controls the first acousto-optic deflector 2 and the second acousto-optic deflector 4, enabling the acousto-optic deflectors to dynamically adjust the laser deflection angle with a microsecond-level response speed. After polarization and deflection processing, the laser beam then enters the 4f system 5 for beam shaping and expansion, and is then guided to the galvanometer 11 by the steering system composed of the first reflector 9 and the second reflector 10. The galvanometer 11 performs a uniform counterclockwise scan along a circle or arc with a radius of curvature rc, while the acousto-optic deflection system finely adjusts the laser deflection angle in the direction of the normal to the circle or arc in real time, forming a precise laser linewidth. The focusing lens 12 precisely focuses the modulated laser beam onto the surface of the workpiece 13 on the processing plane 14, forming a uniformly distributed pulse dot array. The system precisely controls the beam spacing in the normal direction by controlling the beam overlap rate Ra, the number of pulses n, and the beam diameter d. radian interval with the center circle or arc direction The center-to-center spacing of adjacent laser linewidth layers in the central circle or arc direction. To achieve laser linewidth Precise control is achieved. Controller 19 synchronously adjusts the scanning speed Vg of galvanometer 11 and the laser pulse frequency Fr to ensure that the requirements are met. The processing requirements are met, and when the radius of curvature rc is large, the system automatically switches to [specific processing method]. The optimized mode. The XYZ motion platform 15 precisely carries and positions the workpiece 13, and works in conjunction with the galvanometer 11 system to complete the processing of complex laser linewidths. The entire system achieves high-precision, high-efficiency, and stable processing results through digital parameter control.

[0035] It should be noted that the acousto-optic deflector RF driver 17 and controller 19 in this embodiment are integrated modules, and their selection includes, but is not limited to, the GH-AODF 4170 model. Those skilled in the art can select the appropriate model in other embodiments according to the actual working conditions, and no limitation is made here.

[0036] In summary, the working principle of this invention, based on the coordinated operation of the acousto-optic deflector and the galvanometer 11, is as follows: the collimated beam emitted by the laser 1 first enters the acousto-optic deflector and undergoes diffraction under the drive of the radio frequency signal. The +1st order diffracted light is retained for subsequent scanning. The deflection angle θ of this diffracted light is determined by the radio frequency driving frequency f, satisfying… The relationship is given by λ0, where λ is the laser wavelength and V is the wavelength. s The velocity of sound wave propagation in the acousto-optic deflector crystal is given by f1. The laser beam deflected by the acousto-optic deflector then enters the 4f optical system 5, which consists of the first lens 6, the aperture 7, and the second lens 8. The focal lengths of the two lenses are f1 and f2, respectively.

[0037] In the 4f system 5, the laser beam first passes through the first lens 6, forming a spatial spectrum at its rear focal plane, where an adjustable aperture stop 7 is positioned to filter stray light and compensate for aberrations. The laser beam then undergoes a second Fourier transform via the second lens 8, and after reflection by the first mirror 9 and the second mirror 10, it is precisely imaged onto the pupil position of the galvanometer 11. This process eliminates the inherent angular offset of the acousto-optic deflector.

[0038] The laser beam, corrected by the 4f system 5, is reflected by the galvanometer 11 and then focused onto the processing plane 14 by the focusing lens 12. Through this collaborative working mechanism, the entire system effectively corrects the diffraction angle of the acousto-optic deflector as it changes with the radio frequency, thereby ensuring that the beam is accurately transmitted to the galvanometer pupil.

[0039] It should be noted that the galvanometer jump delay in the prior art is 1000μs, while in the ultra-high-speed module application system of the acousto-optic deflector and galvanometer working together in this application, the galvanometer stabilization time is 400μs, the jump time is 100μs, and the jump delay is 500μs at a pulse repetition frequency of 500kHz and a galvanometer speed of 3000mm / s.

[0040] Traditional technology uses only a galvanometer to scan a series of letter patterns at a scanning speed of 40 rad / s, taking 22 ms. However, the ultra-high-speed modular application system based on this application, which uses an acousto-optic deflector in conjunction with a galvanometer, scans patterns in only 5 ms. The galvanometer scans at a uniform speed of 40 rad / s, while the specific shape is filled by the acousto-optic deflector. In existing technologies, acousto-optic deflectors are the best choice for high-speed laser pulse control, but their small scanning range limits their ability to handle large-scale processing. The acousto-optic deflector used in this application has a working bandwidth corresponding to a deflection angle range of 8.040-12.988 mrad and a scanning angle range of 4.9 mrad, offering higher precision. The galvanometer has a scanning angle close to 30 degrees. The ultra-high-speed modular application system using the acousto-optic deflector and galvanometer in conjunction can achieve a 30-degree scanning angle range for the galvanometer, eliminating the drawbacks of large galvanometer inertia, small acousto-optic scanning angle of the acousto-optic deflector, and the contradiction between scanning range and precision, thus achieving high-speed, precision laser scanning processing.

[0041] Table 1 below shows a parameter comparison table between the 4f system and the traditional variable-magnification beam expander.

[0042] Table 1. Spot parameters of the ultra-high-speed module application system with acousto-optic deflector and galvanometer working in tandem.

[0043] Furthermore, compared to existing technologies, the 4f system has an intermediate image point that can filter stray light. The zoom beam expander scheme alters the field of view and entrance pupil position of the light incident on the focusing lens, always causing beam distortion; while the 4f system scheme essentially does not change the entrance pupil position, resulting in better aberration characteristics. In the ultra-high-speed modular application system of this application, which utilizes an acousto-optic deflector and galvanometer working in conjunction, the use of a 4f beam expander system significantly reduces the impact of acousto-optic deflector deflection on system aberrations, and the beam quality is superior to the zoom beam expander scheme.

[0044] The above description is an explanation of the present utility model and not a limitation thereof. The scope of the present utility model is defined by the claims. Within the protection scope of the present utility model, any form of modification may be made.

Claims

1. An ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer, characterized in that: include: Laser (1), half-wave plate (3), first acousto-optic deflector (2), second acousto-optic deflector (4), acousto-optic deflector RF drive (17), 4f system (5), first mirror (9), second mirror (10), galvanometer (11), focusing lens (12), processing plane (14), controller (19), XYZ motion platform (15) and CCD camera (16); The laser (1) is provided with a first acousto-optic deflector (2), a half-wave plate (3), and a second acousto-optic deflector (4) in sequence along the light output direction. The radio frequency driver (17) of the acousto-optic deflector is electrically connected to the first acousto-optic deflector (2) and the second acousto-optic deflector (4). The second acousto-optic deflector (4) is provided with a 4f system (5) and a first reflector (9) in sequence in the light output direction. A second reflector (10) is provided in the reflected light path of the first reflector (9); A galvanometer (11) is provided in the reflected light path of the second reflector (10). The galvanometer (11) is provided with a focusing lens (12) in the light-emitting direction, and the focusing lens (12) is directly facing the processing plane (14). The machining plane (14) is provided with an XYZ motion platform (15) configured to carry the machining workpiece (13). The CCD camera (16) is located on one side of the galvanometer (11) and is configured to detect the position of the workpiece (13); The controller (19) is communicatively connected to the laser (1), galvanometer (11), acousto-optic deflector RF driver (17), XYZ motion platform (15) and CCD camera (16) and is configured to coordinate the collaborative work of the components.

2. The ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer as described in claim 1, characterized in that: The 4f system (5) includes a first lens (6), an aperture (7), and a second lens (8), which are configured to receive a laser beam and perform beam expansion processing; The first lens (6) is located on the light output path of the second acousto-optic deflector (4); the aperture (7) is located on the back focal plane of the first lens (6) and is configured to block the zero-order diffraction light and allow the first-order diffraction light to pass through; the second lens (8) is used to expand the beam and guide it to the first reflector (9).

3. The ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer as described in claim 2, characterized in that: The surfaces of the first lens (6) and the second lens (8) are coated with anti-reflection films, and their average reflectivity is less than 0.25%.

4. The ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer as described in claim 1, characterized in that: The galvanometer (11) is a two-dimensional scanning galvanometer (11), including X-axis and Y-axis galvanometers.

5. The ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer as described in claim 1, characterized in that: The focusing lens (12) is an F-theta lens with a focal length of 170 mm, configured to form a focused spot with a diameter of 20 μm on the processing plane (14).

6. The ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer as described in claim 1, characterized in that: The XYZ motion platform (15) is equipped with a vacuum suction cup for fixing the workpiece (13).

7. The ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer as described in claim 1, characterized in that: It also includes a vacuum cleaner (18) disposed between the focusing lens (12) and the processing plane (14) for absorbing dust generated during the processing.

8. The ultra-high-speed modular application system based on the coordinated operation of an acousto-optic deflector and a galvanometer as described in claim 1, characterized in that: The laser (1) is a nanosecond laser, a picosecond laser, or a femtosecond laser.

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