Laser micro-nano machining device and method based on acousto-optic deflector and rotating mirror

Abstract

The invention relates to the field of laser micro-nano machining, in particular to a laser micro-nano machining device based on an acousto-optic deflector and a rotating mirror and a using method of the laser micro-nano machining device. The laser micro-nano machining device comprises a pulse laser, a reflector set, an acousto-optic deflection module, a signal control unit, a beam splitting module, the rotating mirror and a flat field focusing lens which are sequentially arranged; the acousto-optic deflection module comprises a first acousto-optic deflector and a second acousto-optic deflector, the first acousto-optic deflector and the second acousto-optic deflector are orthogonally arranged, the first acousto-optic deflector is parallel to a rotating shaft of the rotating mirror, and the second acousto-optic deflector is perpendicular to the rotating shaft of the rotating mirror; two acousto-optic deflectors which are orthogonally arranged are arranged, a laser beam is flexibly controlled to deflect to any position in a rectangular scanning area, then the polygon rotating mirror is combined, the polygon rotating mirror can only rotate once along a machining track, the acousto-optic deflectors conduct compensation filling on machining patterns, and the technical effect that any shape can be achieved is achieved.

Description

Technical Field

[0001] The present invention relates to the field of laser micro-nano processing, and in particular to a laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror and a use method thereof. Background Art

[0002] Laser micro-nano processing technology can achieve shape-controlled and property-controlled manufacturing from micron to nanometer scales. It is not limited to simple cutting or punching, but can also be used for material surface texturing, super-hydrophobic preparation, microstructure processing, etc., thus having a wide range of applications in microelectronic devices, semiconductor manufacturing, biomedicine and other fields.

[0003] With the continuous improvement of laser repetition rate, higher requirements are put forward for the processing speed and processing accuracy of laser micro-nano processing. The control ability of laser beam deflection directly determines the processing accuracy and quality. At present, mechanical scanning controllers are mainly used, such as galvanometers, polygonal rotating mirrors, etc. However, mechanical deflection devices have mechanical inertia during trajectory transformation, which affects the processing efficiency and effect. For example, two-dimensional deflection scanning can be achieved by using galvanometers, but due to the existence of mechanical inertia, there will be acceleration and deceleration processes when switching trajectories, resulting in low processing efficiency and energy utilization; secondly, the scanning accuracy of the galvanometer is low, and it is difficult to complete the processing of fine structure patterns; at the same time, the angular velocity of the galvanometer is slow, which is difficult to adapt to the requirements of today's high-repetition-rate lasers, resulting in serious accumulation of thermal effects. Compared with the galvanometer, the polygonal rotating mirror breaks through the shortcoming of the constantly changing swinging speed of the rotating mirror in terms of scanning speed through high-speed rotation. The scanning speed is faster (100 times faster than the galvanometer), more stable, and has a higher damage threshold, but it faces the problem of uncontrollable laser pulses and trajectories (only one-dimensional line scanning can be performed), and the application scenarios are limited. The acousto-optic deflector uses the acousto-optic Bragg diffraction effect to achieve high-speed deflection of the incident laser through efficient regulation of the sound field. It has the characteristics of no mechanical vibration, short response time (at the sub-us level), high deflection angular velocity (up to 1000 radians / second), high scanning accuracy (<0.1urad), and the ability to control the laser beam pulse by pulse. However, the scanning range is narrow and requires coordinated processing with other components.

[0004] In summary, traditional laser micro-nano processing based on mechanical deflectors has problems such as mechanical inertia, low processing efficiency and energy utilization, low processing accuracy, and slow deflection speed. The use of acousto-optic deflectors and polygonal mirrors for coordinated scanning can greatly improve processing efficiency and processing accuracy, meeting the needs of high-speed, high-efficiency, and high-quality processing.

[0005] Prior art CN112705841A discloses an ultrafast laser high-speed micro-nano processing system based on a polygonal scanning mirror. The scanning galvanometer and the polygonal mirror are both inertial components, and cannot accurately process graphics with very drastic changes in the radius of curvature, nor can they achieve pulse-by-pulse control of laser pulses. In addition, there is no parallel processing function, and the processing efficiency is slow. Prior art CN117754121A discloses a multi-mirror laser scanning processing system and method. Although the same processing path can be achieved by connecting multiple mirrors in series, due to the volume of the galvanometer, the processing paths are separate, and it is impossible to process graphics with a certain width pattern, and only a line scanning effect can be achieved, and other graphics cannot be processed. Summary of the invention

[0006] In view of the defects of the related art, the purpose of the present invention is to provide a laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror and a method of using the same, aiming to solve the technical problems of mechanical inertia, low processing efficiency and energy utilization, low processing accuracy and slow deflection speed existing in laser micro-nano processing based on traditional mechanical deflectors.

[0007] According to a first aspect of the present invention, there is provided a laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror, comprising a pulsed laser, a reflector group, an acousto-optic deflection module, a signal control unit, a beam splitting module, a rotating mirror, and a flat-field focusing lens;

[0008] The pulse laser is used to provide pulse laser;

[0009] The reflector group is used to reflect the laser output by the pulse laser into the acousto-optic deflection module, and keep the laser incident on the acousto-optic deflection module at a Bragg angle, thereby changing the deflection position of the laser;

[0010] The signal control unit controls the acousto-optic deflection module to input a set frequency signal into the acousto-optic deflection module;

[0011] The beam splitting module is used to split the laser into mutually parallel beams for output, thereby achieving beam splitting;

[0012] The rotating mirror is used to reflect the mutually parallel light beams to a flat-field focusing lens, and the flat-field focusing lens is used to converge the light beams to a focus, and the focus is used to place the parts to be processed.

[0013] Preferably, the acousto-optic deflection module satisfies: (i) the acousto-optic deflection module comprises a first acousto-optic deflector and a second acousto-optic deflector, the first acousto-optic deflector and the second acousto-optic deflector are placed orthogonally, the first acousto-optic deflector and the rotation axis of the rotating mirror are placed parallel to each other, and the second acousto-optic deflector and the rotation axis of the rotating mirror are placed perpendicular to each other;

[0014] Or (ii) the acousto-optic deflection module includes a first acousto-optic deflector, and the first acousto-optic deflector is placed parallel to the rotation axis of the rotating mirror.

[0015] Preferably, the first acousto-optic deflector and the second acousto-optic deflector both include: a driving signal source, an ultrasonic transducer, and an acousto-optic medium; the acousto-optic medium is connected to the ultrasonic transducer, the electrode on the ultrasonic transducer is connected to the driving signal source, and the signal control unit is connected to the driving signal source.

[0016] Preferably, the material of the acousto-optic medium is selected from quartz, tellurium oxide, and germanium.

[0017] Preferably, the beam splitting module is selected from a flat beam splitter, a cubic beam splitter, and a diffractive optical element.

[0018] Preferably, the rotating mirror is a regular m-gonal cylinder, and m is 3-16.

[0019] Preferably, the laser micro-nano processing device further includes a beam expansion and collimation device, a translation stage, a camera, and a central control unit;

[0020] The beam expansion and collimation device is arranged between the pulse laser and the reflector group, and is used for expanding and collimating the laser beam output by the pulse laser before emitting it;

[0021] The processing component is fixedly arranged on the displacement table and can move along with the displacement table;

[0022] The camera is used to monitor the processing status of the processing component in real time and provide real-time feedback;

[0023] The central control unit is connected to the rotating mirror, the signal synchronization control unit, the camera and the translation stage respectively.

[0024] Preferably, the laser micro-nano processing device further comprises a motor, and the motor is connected to the rotating mirror;

[0025] According to another aspect of the present invention, a laser micro-nano processing method based on an acousto-optic deflector and a rotating mirror is provided, and the specific steps are as follows:

[0026] (1) A pulse laser provides a pulse laser, which is reflected by a reflector group and incident on the acousto-optic deflection module at a Bragg angle; the acousto-optic deflection module is controlled by a frequency signal emitted by a signal control unit to change the deflection angle of a light beam emitted from the acousto-optic deflection module;

[0027] (2) The laser emitted from the acousto-optic deflection module is split into mutually parallel beams by a beam splitting module, thereby achieving beam splitting;

[0028] (3) The split light output by the beam splitting module is reflected by a rotating mirror rotating at a uniform speed to a flat-field focusing lens, and the flat-field focusing lens converges the light beams to a focal point, and the focal point is used to process the processing component;

[0029] (4) connecting a central control unit to the rotating mirror, the signal synchronization control unit, the camera and the translation stage respectively, and sending control signals to the signal control unit, the rotating mirror and the translation stage through the central control unit; the parameters pre-stored in the central control unit include the rotation speed of the rotating mirror, the movement direction of the translation stage, and controlling the driving signal emitted by the signal control unit to the acousto-optic deflection module, so that the acousto-optic deflection module is loaded with a corresponding radio frequency signal frequency;

[0030] (5) A camera is used to monitor the processing status in real time, and the parameters of the processing position, processing accuracy and processing speed are fed back to the central control unit. After receiving the signal, the central control unit sends the signal to the rotating mirror, the translation stage and the signal control unit to adjust the rotation speed of the rotating mirror, the movement direction of the translation stage, and control the driving signal emitted by the signal control unit to the acousto-optic deflection module, so as to keep the processing in the optimal state.

[0031] Preferably, the rotation speed V1 of the rotating mirror is:

[0032]

[0033] Where, L s It represents the length formed on the processing part after the mirror on which the laser is captured rotates by an angle of α; N is the number of pulses output by the pulse laser when the mirror on which the laser is captured rotates by an angle of α; F is the frequency of the pulse laser. Where α = 360° / m, m is the number of sides of the mirror.

[0034] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0035] 1. The present invention provides a laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror, which utilizes the high-speed inertia-free scanning feature of the acousto-optic deflector, wherein the deflection angle of the acousto-optic deflector is proportional to the input signal frequency, and the deflection range is proportional to the Bragg bandwidth. The deflection of the light beam is achieved by high-speed regulation of the sound field. There are no mechanical parts, no mechanical inertia, and high processing efficiency. At the same time, the present invention utilizes the high-precision feature of the acousto-optic deflector, and the control accuracy is guaranteed by the waveform accuracy of the acousto-optic driving source. The waveform frequency accuracy based on digital frequency synthesis is often better than one ten-thousandth, so that the processing quality is good.

[0036] 2. The present invention provides a laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror. Within a controllable laser frequency, the acousto-optic deflector can be controlled pulse by pulse. Two orthogonally placed acousto-optic deflector modules are used to form a rectangular scanning area. The laser beam can be deflected to any position within the scanning area. It has the function of dynamically controlling the light beam, making the overall system flexible and pulse controllable.

[0037] 3. The present invention provides a laser micro-nano processing device and method based on an acousto-optic deflector and a rotating mirror, which utilizes a beam splitting module to split a single light beam into multiple parallel light beams, thereby realizing parallel processing and greatly improving processing efficiency.

[0038] 4. The present invention provides a laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror. The optical elements used are mostly high damage threshold crystals such as quartz, tellurium oxide, and germanium. It can withstand continuous or pulsed laser power much higher than that of liquid crystal and has an extremely high damage threshold.

[0039] 5. The present invention limits the rotation speed of the rotating mirror By theoretically calculating the speed of the rotating mirror and setting it to run at this speed, combined with the acousto-optic deflection module to deflect the pulses at a given frequency, the system can be used to obtain the designed processing pattern. Too fast or too slow speed will cause graphic distortion.

[0040] 6. The present invention flexibly controls the deflection of the laser beam to any position within the rectangular scanning area by setting two orthogonally placed acousto-optic deflectors, and then combines with the polygonal rotating mirror to realize that the polygonal rotating mirror rotates only once along the processing trajectory. The acousto-optic deflector compensates and fills the processing pattern to achieve the technical effects of grooving, punching and other arbitrary shapes. At the same time, combined with the beam splitting module, the output light beam is divided into multiple beams to realize parallel processing and meet the needs of high-speed and high-quality processing; the acousto-optic deflection module has the characteristics of ultra-high scanning speed and pulse-by-pulse deflection of the laser beam to any position within the scanning area, and the rotating mirror has the characteristics of high damage threshold and high scanning speed. The combination of the two can meet the needs of ultra-high speed and high-precision processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic structural diagram of a laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror provided by the present invention;

[0042] Figure 2 It is a structural schematic diagram of the acousto-optic deflection module of the present invention;

[0043] Figure 3 It is a schematic diagram of the scanning area formed by two acousto-optic deflectors within the frequency bandwidth of the present invention after passing through a flat-field focusing lens;

[0044] Figure 4This is a schematic diagram of the structure of a multi-plate beam splitter for beam splitting according to the present invention;

[0045] Figure 5 It is a schematic diagram of a structure in which multiple stereoscopic beam splitters are used for beam splitting in the present invention;

[0046] Figure 6 It is a schematic diagram of the structure of beam splitting using a diffractive optical element in the present invention;

[0047] Figure 7 (a) is a schematic diagram of the actual processing trajectory when the slotting processing effect is performed in Example 1 of the present invention and the pulse correspondence when the deflection is performed without using the acousto-optic deflection module; (b) is a schematic diagram of the corresponding position compensation using the acousto-optic deflection module during the slotting processing in Example 1 of the present invention;

[0048] Figure 8 A schematic diagram of parallel slotting for splitting a light beam by a beam splitting device in Embodiment 1 of the present invention;

[0049] Fig. 9 It is a schematic diagram of using only one acousto-optic deflector for deflection combined with a polygonal rotating mirror to achieve a grooving effect in Embodiment 2 of the present invention;

[0050] Fig.10 (a) is a schematic diagram of the pulse correspondence between the actual processing trajectory and the pulse when the acousto-optic deflection module is not used for deflection during the drilling process in Example 3 of the present invention; (b) is a schematic diagram of the corresponding position compensation using the acousto-optic deflection module during the drilling process in Example 3 of the present invention;

[0051] Fig.11 A schematic diagram of parallel drilling for splitting a light beam by a beam splitting module in Embodiment 3 of the present invention;

[0052] Fig.12 It is a schematic diagram of continuous parallel processing in combination with a translation stage in Example 4 of the present invention;

[0053] Fig.13 It is a schematic diagram of combining a high-speed camera and a translation stage to perform precise continuous parallel processing in Example 5 of the present invention;

[0054] In the figure: 1. pulse laser; 2. beam expansion and collimation device; 3. reflector group; 4. acousto-optic deflection module; 5. signal control unit; 6. beam splitting module; 7. rotating mirror; 8. flat-field focusing lens; 9. processing parts; 10. translation stage; 11. camera; 12. central control unit; 13. reflector; 14. scanned field of view; 41. first acousto-optic deflector; 42. second acousto-optic deflector; 61. flat-plate beam splitter module; 62. cubic beam splitter module; 63. diffractive optical element; 401. driving signal source; 402. ultrasonic transducer; 403. acousto-optic medium. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0056] Example 1

[0057] like Figure 1 As shown, a laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror comprises: a pulse laser 1, a beam expansion and collimation module 2, a reflector group 3, a first acousto-optic deflector 41, a second acousto-optic deflector 42, a signal control unit 5, a beam splitting module 6, a rotating mirror 7, and a flat-field focusing lens 8 arranged in sequence;

[0058] The pulse laser 1 is used to generate a pulse laser beam with variable frequency and variable average power, and the frequency of the pulse laser 1 is variable between 50 and 500 KHz;

[0059] The reflector group 3 is used to adjust the angle of the pulse laser output by the pulse laser 1 when entering the first acousto-optic deflector 41 and the second acousto-optic deflector 42 so as to meet the incident angle of the Bragg angle;

[0060] The signal control unit 5 controls the first acousto-optic deflector 41 and the second acousto-optic deflector 42 simultaneously, so that the deflectors are loaded with radio frequency signals of corresponding frequencies, so that the light beam is deflected to a specified position;

[0061] The structure of the acousto-optic deflection module 4 is as follows Figure 2 As shown, the deflection angle (θ) of the pulsed laser output by the pulsed laser 1 is determined by the frequency (f) of the RF signal and can be expressed as follows:

[0062]

[0063] Where λ is the wavelength of the laser beam, V s is the transmission speed of ultrasonic waves in the acousto-optic medium;

[0064] The scanning range formed by the acousto-optic deflection module 4 within the scanning bandwidth is as follows: Figure 3 As shown, the relationship between the scanning angle range and the working bandwidth can be expressed as:

[0065]

[0066] The scanning field of view (L1) formed on the processing component 9 by the acousto-optic deflection module after being focused by the flat-field focusing lens 8 can be expressed by the formula:

[0067] L1=Δθ·F

[0068] Wherein, F is the focal length of the flat-field focusing lens 8;

[0069] The beam splitting module 6 splits the deflected light beam output by the second acousto-optic deflector 42 into a plurality of parallel light beams for output, and the number and spacing of the plurality of parallel light beams are determined by the setting of the beam splitting module;

[0070] Optionally, the beam splitting module 6 is composed of a plurality of flat beam splitters arranged in an array, such as Figure 4 As shown;

[0071] Optionally, the beam splitting module 6 is composed of a plurality of three-dimensional beam splitters arranged in an array, such as Figure 5 As shown;

[0072] Optionally, the beam splitting module 6 is formed by a diffractive optical element, such as Figure 6 As shown;

[0073] The rotating mirror 7 is driven by a high-speed motor and can rotate at high speed. The relationship between the rotation angular velocity (ω) and the rotation angle (α) can be expressed as:

[0074]

[0075] The scanning speed (V) of the rotating mirror 7 is related to the rotation angular velocity (ω), and the relationship can be expressed by the formula:

[0076] V=r·ω

[0077] In the formula, r is the rotation radius of the rotating mirror. If the rotation radius is determined, the scanning speed is proportional to the rotation angular velocity;

[0078] Optionally, the laser micro-nano processing device based on the acousto-optic deflector and the rotating mirror further includes a beam expansion and collimation module 2, a translation stage 10, a camera 11 and a central control unit 12;

[0079] The beam expansion and collimation module 2 expands and collimates the pulse laser output by the pulse laser 1 to form a parallel beam output;

[0080] The processing component 9 is fixedly arranged on the displacement platform 10 and moves along with the displacement platform 10;

[0081] The central control unit 12 pre-stores the processing method of the processing component 9 and the relevant data of its transformation. The central control unit 12 is connected to the signal control unit 5, the rotating mirror 7, the translation stage 10 and the camera 11, and is used to control the rotation speed of the rotating mirror 7 and the movement direction of the translation stage 10 according to the processing data, and control the driving signal emitted by the signal control unit 5 to the first acousto-optic deflection module 41 and the second acousto-optic deflection module 42 so that they load the corresponding radio frequency signal frequency to perform a preset processing program. The camera 11 monitors the changes of the processing surface in real time and compares it with the preset data in real time. When it is different from the preset data, it is fed back to the central control unit 12 to adjust the parameters to achieve the expected effect.

[0082] refer to Figure 2 The acousto-optic deflection module 4 includes a first acousto-optic deflector 41 and a first acousto-optic deflector 42, wherein the acousto-optic deflector is composed of a driving signal source 401, an ultrasonic transducer 402, and an acousto-optic medium 403; the ultrasonic transducer 402 is composed of several layers of media attached to the surface of the acousto-optic medium 403, wherein the electrode layers at both ends of the piezoelectric layer are connected to the driving signal source 401; when the first acousto-optic deflector 41 and the first acousto-optic deflector 42 are working, the driving signal source 401 can output radio frequency signals of different frequencies, and realize the change from mechanical vibration to the same frequency acoustic signal at the position of the ultrasonic transducer 402, thereby generating ultrasonic waves in the acousto-optic medium 403, so that the refractive index of the acousto-optic medium 403 changes. In this embodiment, the material of the acousto-optic medium 403 is quartz crystal, the material of the ultrasonic transducer 402 is lithium niobate crystal, and the frequency range of the radio frequency signal output by the driving signal source 401 is 140MHz to 200MHz, and the center frequency is 170MHz.

[0083] The first acousto-optic deflector 41 and the second acousto-optic deflector 42 are of the same type, and produce corresponding angular deflections on the light beam according to the control signal of the signal control unit 5 .

[0084] refer to Figure 3 After the incident laser beam passes through the first acousto-optic deflection module 41 and the second acousto-optic deflection module 42, it is scanned within the scanning bandwidth to obtain a deflected beam output, and then passes through the flat-field focusing lens 8 to form a scanning field of view. In this embodiment, the focal length of the flat-field focusing lens 8 is 100 mm, and the frequency output by the pulse laser 1 is 355 nm. Therefore, the side length of the obtained scanning field of view 14 is calculated as

[0085] L1=370um.

[0086] refer to Figure 4The deflected light beam output by the acousto-optic deflection module is split by the beam splitting module 6 to form n mutually parallel light beams. The beam splitting module is composed of n flat plate beam splitters, and the spacing of the parallel light beams is determined by the spacing between the flat plate beam splitters.

[0087] refer to Figure 7 In (a), when the frequency provided by the signal control unit 5 of the first acousto-optic deflection module 41 and the second acousto-optic deflection module 42 to both is the center frequency of 170 MHz, the deflected light beam is emitted in parallel (adjusted in the horizontal direction with the diffraction deflection direction at the center frequency), and the emitted light spot does not deflect relatively, and then is scanned at high speed by the polygonal rotating mirror 7, and the obtained processing trajectory is as follows Figure 7 As shown in the red dots in (a); if we want to get Figure 7 In the actual processing pattern in (a), it is necessary to use the acousto-optic deflection module to control the position of the pulse light beam, so that the laser pulse originally at the red dot position is placed at the gray dot after being deflected by the acousto-optic deflection module; this embodiment illustrates the deflection of 5 light pulses in the normal direction of the movement direction of the hexagonal mirror. It should be noted that the spacing between the pulsed lasers and the number of deflections are determined by the scanning field of view 14 formed by the acousto-optic deflection module and its own deflection ability, and are not limited to the spacing and number of deflections shown in this figure.

[0088] refer to Figure 7 As shown in (b), the deflection position required by the first acousto-optic deflection module 41 and the second acousto-optic deflection module 42 is the pulse point trace actually processed minus the pulse point trace when no deflection occurs. The relative deflection position obtained is processed by the central control unit 12 and becomes the frequency signal in the signal control unit 5. When the signal control unit 5 provides the frequency signal to the acousto-optic deflection module (41 and 42), the acousto-optic deflection module deflects the laser beam pulse by pulse. At the same time, the central control unit 12 controls the movement speed of the rotating mirror 7 to match the overlap rate and other parameters of the designed processing pattern, and finally completes the processing task of the processing pattern.

[0089] refer to Figure 8 After the beam splitting module 6 is used for beam splitting, the generated multiple parallel beams are scanned at high speed by the polygonal mirror to form a processing track as shown in FIG. Figure 8 As shown. The processing width formed by each beam depends on the scanning width (L1) formed by the acousto-optic deflection module. In this embodiment, the processing width formed by each beam is up to 370um. The distance between the two beams is defined by the beam splitting module distance of the beam splitting module 6. The width of each beam and the distance between the two beams can be defined according to the actual processing pattern to meet the processing requirements.

[0090] Example 2

[0091] Based on the first embodiment, this embodiment provides another processing method, which uses only one horizontally placed acousto-optic deflector 41. The acousto-optic deflector 41 can control the characteristics pulse by pulse to control the position of each laser pulse and whether deflection occurs, so as to achieve the processing effect.

[0092] refer to Fig. 9 , by controlling the signal control unit 5, during the processing, a signal with a center frequency of 170MHz is continuously sent to the acousto-optic deflector 42, then the acousto-optic deflector 42 is only in the center frequency deflection pulse, and the signal control unit 5 is controlled to send a bandwidth frequency to the acousto-optic deflection module 41, and the bandwidth frequency is 140-200MHz, then the deflected light beam is scanned in the horizontal direction (the horizontal direction is perpendicular to the rotation direction of the polygonal rotating mirror). During the processing, the signal control unit 5 continuously sends a bandwidth frequency to the acousto-optic deflection module 41, so that it scans back and forth in the horizontal direction without inertia, or calculates the required number of deflections according to the pulse overlap rate based on the width of the processing pattern, and then scans back and forth within this frequency range corresponding to the corresponding frequency. In the process of the acousto-optic deflection module 4 scanning the light beam deflection, the rotating mirror 7 scans at high speed, and the processing pattern is as follows Fig. 9 The degree of interleaving of the two laser pulses perpendicular to the movement direction of the rotating mirror 7 is determined by the rotation speed of the rotating mirror 7; the overlap rate of the two laser pulses horizontal to the movement direction of the rotating mirror 7 is still a set parameter. Since the acousto-optic deflection module has the ability to control pulse by pulse, at the beginning and end of the processing, the signal control unit 5 does not send a frequency signal to the acousto-optic deflection module 4 (the laser pulse does not deflect at this time), and the laser pulse can no longer be projected onto the processing surface. Fig. 9 The hollow circle shows the pulse that is not projected onto the machining surface. At this time, a rectangular area can still be machined.

[0093] Only one acousto-optic deflection module is used in the device, and the signal control unit 5 only controls the acousto-optic deflection module to perform the above operations, making the device more concise. The beam splitting module 6 can also be a combination of several cubic beam splitters, see Figure 5 , split the deflected light beam.

[0094] The embodiment of the present invention uses only one acousto-optic deflector, which utilizes the characteristic of the acousto-optic deflector in deflecting the laser beam pulse by pulse. By shielding the laser pulse at a specific position, the processing effect achieved by two orthogonally placed acousto-optic deflection modules is achieved, which can meet the beneficial effects of special processing needs, has a simpler structure, and reliable output.

[0095] Example 3

[0096] On the basis of the first embodiment, this embodiment provides another processing effect, which can be used for punching applications. The processing device based on the acousto-optic deflector and the rotating mirror makes the processing system based on the polygonal rotating mirror no longer only suitable for high-speed linear scanning, which greatly expands the application scope of the polygonal rotating mirror.

[0097] refer to Fig.10 In the application, similar to the processing method of the first embodiment, when the signal control unit 5 provides the center frequency to the acousto-optic deflection module 4, the light beam is at the center of the deflection range, and when the rotating mirror 7 moves at a high speed, a red dot is formed, such as Fig.10 If hole processing is to be performed, the pulse points required for drilling should be sorted, and then subtracted from the trajectory when no relative deflection occurs to obtain the relative deflection position of the acousto-optic deflection module to the laser pulse, as shown in FIG. Fig.10 When processing is performed, the frequency of the pulse laser 1 is selected as the frequency used for laser processing, the central control unit 12 stores all relative deflection position data and converts it into a frequency signal in the signal control unit 5, and the signal control unit 5 then sends the frequency signal to the acousto-optic deflection module, and the acousto-optic deflection module deflects in turn according to the given frequency, and the central control unit 12 simultaneously controls the rotation speed of the rotating mirror 7, and finally obtains the processed pattern.

[0098] refer to Fig.11 , using the multi-plate beam splitter module 61 (such as Figure 4 After the beam is split (as shown in FIG. 1 ), the generated multiple parallel beams are scanned at high speed by the polygonal rotating mirror to form a processing track as shown in FIG. Fig.11 As shown. The processing width formed by each beam split depends on the scanning width (L1) formed by the acousto-optic deflection module. In this embodiment, the maximum diameter of a single hole formed by each beam split is 370um. The distance between two beam splits is defined by the beam splitting module distance of the beam splitting module 6. The width of each beam split and the distance between the two beam splits can be defined according to the actual processing pattern to meet the processing requirements.

[0099] In an alternative embodiment, the multi-plate beam splitter module 61 may also be a combination of several cubic beam splitters.

[0100] The embodiment of the present invention applies a radio frequency signal of a specified frequency to two orthogonally placed acousto-optic deflection modules, which can realize arbitrary deflection of the laser beam within the scanning range and scan into any pattern. It not only expands the application scope of the polygonal rotating mirror, but also provides a new scanning strategy, greatly improving the processing efficiency and meeting the needs of high-speed and high-efficiency processing.

[0101] Example 4

[0102] On the basis of the above-mentioned embodiments, the present embodiment introduces the translation stage 10 to realize micro-nano processing in a very large range and meet the demand for larger-scale laser micro-nano processing.

[0103] refer to Fig.12 After the rotating mirror 7 rotates at high speed, a corresponding processing pattern is processed on the processing plane. The beam splitting module 6 divides a deflected light beam into multiple light paths for output. The light beam passes through the rotating surface of the polygonal rotating mirror 7 once, and then several patterns can be processed on the processing plane, which greatly improves the processing efficiency. When the number of rotations of the polygonal rotating mirror 7 meets the required processing requirements, the central control unit 12 controls the translation stage 10 to move. After moving to the next processing position, the central control unit 12 controls the polygonal rotating mirror 7 again to continue processing the required pattern.

[0104] The embodiment of the present invention applies a radio frequency signal of a specified frequency to two orthogonally placed acousto-optic deflection modules, which can realize arbitrary deflection of the laser beam within the scanning range. At the same time, the translation stage 10 is introduced to dynamically adjust the processing position during the processing, which not only improves the processing efficiency but also provides a larger processing format to meet the needs of high-speed and ultra-large format processing.

[0105] Example 5

[0106] On the basis of the above-mentioned embodiments, this embodiment can realize real-time observation of the processing effect during the processing, and control the corresponding control components according to the processing effect to meet the processing requirements.

[0107] refer to Fig.13The central control unit 12 controls the displacement stage 10 to move. After moving to the next processing position, the camera 11 captures the position of the displacement stage 10 in real time. When it is detected that the displacement stage 10 reaches the designated processing position, the high-speed camera 11 feeds back the position signal to the central control unit 12. The central control unit 12 then sends a signal to the signal control unit 5 to provide a corresponding frequency signal so that the laser pulse is deflected again after passing through the acousto-optic deflection module 4. At the same time, the central control unit 12 controls the rotation speed of the polygonal rotating mirror 7 so that the acousto-optic deflection module 4 and the polygonal rotating mirror 7 cooperate with each other to complete the processing. During the processing, the high-speed camera 11 monitors the processing status of the processing surface in real time. When the processing depth and quality of the processing surface meet the processing requirements, the high-speed camera 11 feeds back a signal to the central control unit 12. The central control unit 12 sends a signal to the signal control unit 5 according to the feedback information to stop the laser pulse deflection. At the same time, the central control unit 12 also sends a corresponding displacement instruction to the translation stage 10. When the translation stage 10 moves to the next processing surface, the high-speed camera 11 feeds back a signal to the central control unit 12. The central control unit 12 sends a command to the signal control unit 5 again, and the above operation is repeated until the processing is completed.

[0108] The embodiment of the present invention introduces a high-speed camera, which can monitor the processing status of the processing surface in real time during the processing and provide real-time feedback on the processing status, which not only improves the processing quality of ultra-large-format processing, but also improves the processing efficiency.

[0109] The present invention provides a laser micro-nano processing method based on an acousto-optic deflector and a polygonal rotating mirror, which is applied to a laser micro-nano processing device based on an acousto-optic deflector and a polygonal rotating mirror. It can realize efficient laser micro-nano processing, improve the processing speed, and thus improve the processing efficiency, while ensuring the processing quality, and can be processed according to the processing style required by the user to meet the use of various practical needs.

[0110] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror, characterized in that: It comprises a pulse laser (1), a reflector group (3), an acousto-optic deflection module (4), a signal control unit (5), a beam splitting module (6), a rotating mirror (7), and a flat-field focusing lens (8); The pulse laser (1) is used to provide pulse laser; The reflector group (3) is used to reflect the laser light output by the pulse laser (1) into the acousto-optic deflection module (4), and to keep the laser light incident on the acousto-optic deflection module (4) at a Bragg angle, thereby changing the deflection position of the laser light; The signal control unit (5) controls the acousto-optic deflection module (4) to input a set frequency signal into the acousto-optic deflection module (4); The beam splitting module (6) is used to split the laser into mutually parallel beams for output, thereby achieving beam splitting; The rotating mirror (7) is used to reflect the mutually parallel light beams to a flat-field focusing lens (8), and the flat-field focusing lens (8) is used to converge the light beams to a focal point, and the focal point is used to place a component to be processed.

2. The laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror according to claim 1, characterized in that: The acousto-optic deflection module (4) satisfies the following requirements: (i) the acousto-optic deflection module (4) comprises a first acousto-optic deflector (41) and a second acousto-optic deflector (42), the first acousto-optic deflector (41) and the second acousto-optic deflector (42) are arranged orthogonally, the first acousto-optic deflector (41) and the rotation axis of the rotating mirror (7) are arranged parallel to each other, and the second acousto-optic deflector (42) and the rotation axis of the rotating mirror (7) are arranged perpendicular to each other; Or (ii) the acousto-optic deflection module (4) comprises a first acousto-optic deflector (41), and the rotation axis of the first acousto-optic deflector (41) and the rotating mirror (7) are parallel to each other.

3. The laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror according to claim 2, characterized in that: The first acousto-optic deflector (41) and the second acousto-optic deflector (42) both comprise: a driving signal source (401), an ultrasonic transducer (402), and an acousto-optic medium (403); the acousto-optic medium (403) is connected to the ultrasonic transducer (402), the electrode on the ultrasonic transducer (402) is connected to the driving signal source (401), and the signal control unit (5) is connected to the driving signal source (401).

4. The laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror according to claim 1, characterized in that: The material of the acousto-optic medium (403) is selected from quartz, tellurium oxide, and germanium.

5. The laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror according to claim 1, characterized in that: The beam splitting module (6) is selected from a flat beam splitter, a cubic beam splitter, and a diffractive optical element.

6. The laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror according to claim 1, characterized in that: The rotating mirror is a regular m-gonal cylinder, where m is 3-16.

7. The laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror according to claim 3, characterized in that: The laser micro-nano processing device also includes a beam expansion and collimation device (2), a processing component (9), a displacement stage (10), a camera (11), and a central control unit (12); The beam expansion and collimation device (2) is arranged between the pulse laser (1) and the reflector group (3), and is used for expanding and collimating the laser beam output by the pulse laser (1) before emitting it; The processing component (9) is fixedly arranged on the displacement platform (10) and can move along with the displacement platform (10); The camera (11) is used to monitor the processing status of the processing component (9) in real time and provide real-time feedback; The central control unit (12) is respectively connected to the rotating mirror (7), the signal synchronization control unit (5), the camera (11) and the displacement stage (10).

8. The laser micro-nano processing device based on an acousto-optic deflector and a rotating mirror according to claim 1, characterized in that: The laser micro-nano processing device also includes a motor, which is connected to the rotating mirror (7).

9. A laser micro-nano processing method based on an acousto-optic deflector and a rotating mirror according to any one of claims 1 to 8, characterized in that: The specific steps are: (1) A pulse laser provides a pulse laser, which is reflected by a reflector group and incident on the acousto-optic deflection module at a Bragg angle; the acousto-optic deflection module is controlled by a frequency signal emitted by a signal control unit to change the deflection angle of a light beam emitted from the acousto-optic deflection module; (2) The laser emitted from the acousto-optic deflection module is split into mutually parallel beams by a beam splitting module, thereby achieving beam splitting; (3) The split light output by the beam splitting module is reflected by a rotating mirror rotating at a uniform speed to a flat-field focusing lens, and the flat-field focusing lens converges the light beams to a focal point, and the focal point is used to process the processing component; (4) connecting a central control unit to the rotating mirror, the signal synchronization control unit, the camera and the translation stage respectively, and sending control signals to the signal control unit, the rotating mirror and the translation stage through the central control unit; the parameters pre-stored in the central control unit include the rotation speed of the rotating mirror, the movement direction of the translation stage, and controlling the driving signal emitted by the signal control unit to the acousto-optic deflection module, so that the acousto-optic deflection module is loaded with a corresponding radio frequency signal frequency; (5) A camera is used to monitor the processing status in real time, and the parameters of the processing position, processing accuracy and processing speed are fed back to the central control unit. After receiving the signal, the central control unit sends the signal to the rotating mirror, the translation stage and the signal control unit to adjust the rotation speed of the rotating mirror, the movement direction of the translation stage, and control the driving signal emitted by the signal control unit to the acousto-optic deflection module, so as to keep the processing in the optimal state.

10. The laser micro-nano processing method based on an acousto-optic deflector and a rotating mirror according to claim 9, characterized in that: The rotation speed V1 of the rotating mirror is: Where, L s represents the length formed on the processing component after the lens of the rotating mirror at the laser intake rotates by an angle of α, N is the number of pulses output by the pulse laser when the lens of the rotating mirror at the laser intake rotates by an angle of α, and F is the frequency of the pulse laser; in α=360° / m, where m is the number of sides of the rotating mirror.

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