A laser processing calibration device and method based on coherent imaging

Abstract

This invention relates to the field of laser processing technology, specifically to a laser processing calibration device and method based on coherent imaging. The device includes a fixed module, which is fixedly connected to a reference arm module and a sample arm module. The sample arm module is fixedly connected to a laser processing equipment, which contains a galvanometer and a field lens. The fixed module includes a fixed box, inside which a beam splitter is installed. The connecting optical fibers between the fixed module, the reference arm module, and the sample arm module are all fixedly installed in the fixed box. This application, through an original rigid integrated structural design, solidifies the vibration-sensitive interferometer core optical fiber and optical components into a single unit, significantly suppressing vibration-induced optical path noise from a physical source. This effectively solves the core problems of imaging blurring, large processing errors, and low system reliability caused by fiber vibration in existing technologies, significantly improving the accuracy, repeatability, and long-term stability of laser processing.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and specifically to a laser processing calibration device and method based on coherent imaging. Background Technology

[0002] In laser processing calibration systems based on optical coherence imaging (such as OCT), core components typically include a light source, coupler, circulator, reference arm module, sample arm module (integrating scanning and focusing optical elements), and spectral measurement (such as a spectrometer). These modules are generally connected via single-mode optical fibers to form an interference optical path.

[0003] However, existing optical fibers often lack effective fixing and vibration isolation protection, making them prone to swaying due to external mechanical vibrations or air disturbances in actual working environments. This fiber vibration directly causes dynamic changes in the physical length and refractive index of the optical transmission path, introducing random optical path difference fluctuations and phase noise into interferometry. This not only reduces the quality of coherent imaging, causing blurring, distortion, and a decrease in signal-to-noise ratio in the reconstructed image, directly undermining the measurement benchmark upon which subsequent high-precision calibration depends, but also contaminates the precise phase measurement signal, causing calibration algorithms to fail and errors to accumulate over long-term operation, ultimately rendering the entire calibration system inaccurate.

[0004] Therefore, how to suppress fiber vibration and achieve stable installation and effective vibration isolation of fiber connections in the interference optical path is the core technical challenge for improving the reliability, accuracy and long-term stability of such laser processing calibration systems, and it is also a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In order to overcome the problems of decreased imaging quality, reduced processing accuracy and insufficient system stability caused by fiber vibration in the prior art, this application provides a laser processing calibration device and method based on coherent imaging.

[0006] The laser processing calibration device and method based on coherent imaging provided in this application adopts the following technical solution: First aspect A laser processing calibration device based on coherent imaging includes a fixing module, which is fixedly connected to a reference arm module and a sample arm module. The sample arm module is fixedly connected to a laser processing equipment, which contains a galvanometer and a field lens. The fixing module includes a fixing box, inside which a beam splitter is installed. A first fiber optic connector, a second fiber optic connector, a third fiber optic connector, and a fourth fiber optic connector are installed on the side wall of the fixing box. One end of the first fiber optic connector is connected to the beam splitter via a second fiber optic cable, and the first end is connected to a light source. One end of the second fiber optic connector is connected to the beam splitter via a third fiber optic cable, and the second end is connected to a spectrometer. One end of the third fiber optic connector is connected to the beam splitter via a fourth fiber optic cable, and the third end is connected to the reference arm module. One end of the fourth fiber optic connector is connected to the beam splitter via a fifth fiber optic cable, and the fourth end is connected to the sample arm module. The beam splitter, the second fiber optic cable, the third fiber optic cable, the fourth fiber optic cable, and the fifth fiber optic cable are all fixed inside the fixing box.

[0007] By adopting the above technical solution, the core optical components of the interferometer and all the key connecting optical fibers are integrated and fixed in a rigid housing. This housing is then rigidly connected to the reference arm module, sample arm module, and laser processing equipment as a whole. This integrated, rigid mechanical structure design fundamentally eliminates relative displacement and swaying caused by loose connections between modules. The secure fixing of the core optical fiber within the housing directly suppresses the fiber's own deformation and vibration, thereby greatly reducing the generation of random optical path difference and phase noise in the interference optical path. This provides a physical basis for obtaining a stable, high signal-to-noise ratio coherent imaging signal, thus ensuring the initial accuracy and long-term reliability of laser processing calibration based on this imaging result.

[0008] Furthermore, the reference arm module includes a reference arm mounting box, which is fixedly mounted on the fixed box. Inside the reference arm mounting box are a first collimating mirror and a first reflecting mirror that correspond to each other. The first collimating mirror is connected to the third fiber optic connector.

[0009] By adopting the above technical solution, the optical components of the reference arm, such as the first collimating mirror and the first reflecting mirror, are integrated into a separate mounting box, which is then rigidly connected to the fixed box. This modular design not only facilitates assembly and independent adjustment but also incorporates the reference optical path into the overall rigid structure. The rigid connection with the fixed module ensures the stability of the optical path reference of the reference arm, while the independent box provides protection for the internal optical path, together providing an extremely stable and repeatable reference reference for the entire interferometric system.

[0010] Furthermore, the sample arm module includes a sample arm mounting box, one side of which is fixedly connected to the fixed box, and the other side of which is fixedly connected to the laser processing equipment. A second collimating mirror and a second reflecting mirror are installed inside the sample arm mounting box. The second collimating mirror is connected to the fourth fiber optic connector. The second reflecting mirror is connected to the laser processing equipment.

[0011] By adopting the above technical solution, the sample arm module serves as a crucial bridge connecting the stable interferometer core and the laser processing equipment containing moving parts. Its mounting box is rigidly connected to the fixed box and the processing equipment on both sides, respectively. This design solidifies the optical transmission path of the sample arm into a stable mechanical structure, effectively isolating the direct impact of vibrations that may originate from the laser processing equipment on the upstream interferometric measurement optical path, ensuring the long-term consistency and stability of the measurement beam's direction.

[0012] Furthermore, an optical path adjustment mechanism is provided between the first collimating mirror and the first reflecting mirror.

[0013] By employing the above technical solution, the optical path length of the reference arm can be precisely and continuously adjusted according to the initial length of the sample arm or specific measurement requirements. Precise adjustment of the optical path allows for optimal interference between the reference light and the sample light at the coupler, resulting in the highest contrast interference signal. This is a prerequisite for achieving high-sensitivity, high-axial-resolution coherent imaging.

[0014] Furthermore, the reference arm mounting box is equipped with a first angle adjustment mechanism for adjusting the angle of the first reflector.

[0015] By employing the above technical solution, high-precision, backflip-free two-dimensional fine-tuning of the first reflecting mirror angle is achieved. This ensures optimal matching of the beam returning from the reference arm and the beam returning from the sample arm in terms of spatial mode and wavefront, thereby maximizing interferometry efficiency and further improving the signal-to-noise ratio and stability of the interferometric image.

[0016] Furthermore, the sample arm mounting box is equipped with an adjustment mechanism for adjusting the position of the second collimating lens.

[0017] By employing the above technical solution, the axial position of the second collimating lens can be precisely adjusted. Adjusting its position optimizes the collimation of the light emitted from the sample arm fiber, ensuring that a perfectly parallel beam is directed towards the laser processing equipment. This is crucial for the subsequent beam combining, scanning, and focusing within the processing equipment, and is fundamental to ensuring the overall system's light energy utilization and the quality of the final processing and imaging spot.

[0018] Furthermore, the sample arm mounting box is equipped with a second angle adjustment mechanism for adjusting the angle of the second reflector.

[0019] By adopting the above technical solution, a high-precision control capability for the direction of the beam emitted from the sample arm is provided. By finely adjusting the angle of the second reflector, it can be ensured that the collimated probe beam emitted from the sample arm module can be accurately and perpendicularly incident on the predetermined interface of the laser processing equipment, achieving perfect spatial beam combining and common path with the processing laser. This is the core link in achieving precise calibration for what you see is what you get.

[0020] Furthermore, the optical splitter includes a circulator and a coupler, with a first optical fiber connected between the circulator and the coupler. The circulator, the coupler, and the first optical fiber are all fixedly installed inside the fixed box.

[0021] By adopting the above technical solution, the circulator, coupler, and first optical fiber are directly fixed inside the fixed box, realizing the physical solidification of the optical path connecting the splitting devices. This design eliminates the free hanging part of this key optical fiber, making it an integral part of the rigid fixed box, thereby effectively isolating the slight deformation and sway caused by external mechanical vibration and airflow disturbance directly transmitted to the optical fiber.

[0022] Second aspect A laser processing calibration method based on coherent imaging, applied to the laser processing calibration apparatus based on coherent imaging described in the first aspect, includes: S1. System Integration and Optical Path Stabilization: S11. Rigidly connect the fixing module, reference arm module, and sample arm module into a whole, and rigidly connect the sample arm module to the laser processing equipment; S12. Fix the first optical fiber, the second optical fiber, the third optical fiber, the fourth optical fiber and the fifth optical fiber in the fixed box to keep the optical path of the first optical fiber, the second optical fiber, the third optical fiber, the fourth optical fiber and the fifth optical fiber physically stable. S2, Coherent Imaging and 3D Measurement: S21. Start the light source. The probe light generated by the light source is split into a reference beam and a sample beam by the fixing module, and then enters the reference arm module and the sample arm module respectively. S22. The reference beam is reflected by the first reflecting mirror, and the sample beam is emitted from the sample arm module and the laser processing equipment and then reflected after irradiating the sample surface. S23. After the reference beam and the sample beam return, they interfere within the fixed module. The spectrometer acquires the interference spectrum and reconstructs the three-dimensional topographic image of the target area of ​​the workpiece to be processed. S3. Machining coordinate extraction and positioning: S31. Based on the three-dimensional topography image obtained in S2, extract the three-dimensional spatial coordinates of the features to be processed in the imaging coordinate system; S32. Control the galvanometer and field mirror set inside the laser processing equipment to position the focal point of the beam shared by imaging and processing to the coordinates; S4, Closed-loop control processing: S41. Start the processing laser of the laser processing equipment to process the points located in step S3; S42. During the processing, repeat steps S2 and S3 to perform real-time coherent imaging measurement of the processing area, compare the measured actual processing morphology with the preset target morphology, and generate an error signal. S5. Dynamic calibration and compensation: S51. Based on the error signal generated in step S4, dynamically adjust the processing parameters of the laser processing equipment to achieve closed-loop calibration and error compensation of the processing process.

[0023] By employing the above technical solution, a highly stable calibration device is combined with a closed-loop control process. The method begins with the pursuit of ultimate physical stability of the device to ensure the absolute reliability of the three-dimensional measurement results. Coordinate extraction and positioning based on this stable measurement have high accuracy. During processing, the same stable system is used for real-time online measurement, and the results are compared with the target to generate an error signal, which is ultimately used for dynamic compensation.

[0024] This method forms a precision closed loop based on stable measurement and driven by real-time feedback, transforming the static structural stability of the device into dynamic precision control capability of the processing process, thereby systematically improving the accuracy, consistency and intelligence level of laser processing.

[0025] Furthermore, in step S1, the method of fixing the first optical fiber, the second optical fiber, the third optical fiber, the fourth optical fiber, and the fifth optical fiber includes injecting a functional fluid with specific viscosity and thermal conductivity into the fixing box, so that the optical fibers in the box are immersed in the functional fluid to suppress vibration and improve heat dissipation.

[0026] By employing the above technical solution, an enhanced method for improving optical path stability is provided. The injected functional fluid not only actively absorbs and attenuates mechanical vibrations through viscous damping, but also uniformly dissipates the heat generated by the components. This dual effect can more thoroughly eliminate random fluctuations and slow drifts in the optical path, enabling the phase stability of the interferometric system to reach a new level and providing a near-ideal noise-free reference for all subsequent measurement and calibration steps.

[0027] Beneficial effects achieved: This application provides a laser processing calibration device and method based on coherent imaging. Through a unique rigid integrated structural design, the core fiber of the interferometer, which is susceptible to vibration, is solidified into a single unit, significantly suppressing vibration-induced optical path noise at its physical source. The rigid connections and precision adjustment mechanisms of each module within the device ensure long-term stability and accurate alignment of the optical path. The method implemented based on this stabilizing device achieves a complete calibration process, from stable measurement to precise positioning and closed-loop compensation. This effectively solves the core problems of existing technologies, such as blurred imaging, large processing errors, and low system reliability caused by fiber vibration, significantly improving the accuracy, repeatability, and long-term stability of laser processing. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of one embodiment of this application.

[0029] Figure 2 This is a structural exploded view of one embodiment of this application.

[0030] Figure 3 This is a schematic diagram of the internal structure of one embodiment of this application.

[0031] Figure 4 This is a schematic diagram of the structural principle of one embodiment of this application.

[0032] Figure 5 This is a schematic diagram of the connection structure of the fixed module in one embodiment of this application.

[0033] Figure 6 This is an exploded view of the optical path adjustment mechanism in one embodiment of this application.

[0034] Figure 7 This is an exploded view of the structure of the first angle adjustment mechanism in one embodiment of this application.

[0035] Figure 8 This is an exploded view of the position adjustment mechanism in one embodiment of this application.

[0036] Figure 9 This is an exploded view of the structure of the second angle adjustment mechanism in one embodiment of this application.

[0037] Figure 10 This is an exploded view of the sealing cap structure in one embodiment of this application.

[0038] Explanation of reference numerals in the attached drawings: 100, Fixed module; 101, Fixed box; 102, Circulator; 103, Coupler; 104, First optical fiber; 105, First optical fiber connector; 106, Second optical fiber connector; 107, Third optical fiber connector; 108, Fourth optical fiber connector; 109, Second optical fiber; 110, Third optical fiber; 111, Fourth optical fiber; 112, Fifth optical fiber; 113, Sealing cap; 114, Injection hole; 115, Vent hole; 116, Sealing plug; 200, Reference Reference arm module; 201, Reference arm mounting box; 202, First collimating lens; 203, First reflecting mirror; 300, Sample arm module; 301, Sample arm mounting box; 302, Second collimating lens; 303, Second reflecting mirror; 400, Laser processing equipment; 401, Galvanometer; 402, Field lens; 500, Optical path adjustment mechanism; 501, Third reflecting mirror; 502, Slide rail; 503, First reflecting mirror mount; 504, Adjusting screw; 505, Adjusting knob; 506, Second reflecting mirror mount; 507. Fourth reflecting mirror; 508. Fifth reflecting mirror; 509. Sixth reflecting mirror; 600. First angle adjustment mechanism; 601. First fixed mounting plate; 602. First direction adjustment plate; 603. Second direction adjustment plate; 604. First elastic connecting part; 605. Second elastic connecting part; 606. First adjusting screw; 607. First ball bearing; 608. Second adjusting screw; 609. Second ball bearing; 700. Position adjustment mechanism; 701. Outer cylinder; 702. Inner cylinder; 703, Lens tube; 704, Adjustment groove; 705, Adjustment disc; 706, Eccentric pin; 707, Drive groove; 708, Clearance hole; 800, Second angle adjustment mechanism; 801, Second fixed mounting plate; 802, Third direction adjustment plate; 803, Fourth direction adjustment plate; 804, Third elastic connection part; 805, Fourth elastic connection part; 806, Third reflector mount; 807, Third adjustment screw; 808, Third ball bearing; 809, Fourth adjustment screw; 810, Fourth ball bearing. Detailed Implementation

[0039] The following combination Figures 1-10 This application will be described in further detail.

[0040] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] This application discloses a laser processing calibration device and method based on coherent imaging.

[0043] Example 1

[0044] Please refer to the above as well. Figures 1 to 10 In one embodiment of this application, a laser processing calibration device based on coherent imaging includes a fixed module 100, a reference arm module 200, a sample arm module 300, and a laser processing device 400, a light source, and a spectrometer that work in conjunction with these modules. The laser processing device 400 internally includes a galvanometer 401 and a field mirror 402. The galvanometer 401 is configured as a two-dimensional scanning galvanometer, and the field mirror 402 is configured as an f-theta field mirror or a telecentric field mirror. The light source is preferably a broadband low-coherence light source, such as a superluminescent diode (SLD) or a swept-frequency light source. The spectrometer is preferably a high-speed linear array detector.

[0045] The fixed module 100, reference arm module 200, and sample arm module 300 are fixedly connected to the flange by bolts and locating pins, forming a rigid, integrated optical platform body, which greatly enhances the mechanical stability of the overall structure. The output end of the sample arm module 300 is rigidly connected to the optical head of the laser processing equipment 400, ensuring that the imaging optical path and the processing optical path are strictly aligned in the end space.

[0046] The fixed module 100 is the core component of this invention for achieving stable optical path integration. It includes a sealed fixed box 101. The fixed box 101 is preferably made of a material with high rigidity and a low coefficient of thermal expansion, such as aluminum alloy or Invar. The interior of the fixed box 101 can be treated for light-diffusing and anti-reflection. A circulator 102 and a coupler 103 are fixedly installed inside the fixed box 101; the circulator 102 and coupler 103 are beam splitting devices. The circulator 102 and coupler 103 are connected by a first optical fiber 104 with extremely low relaxation, fixed with adhesive, forming the core beam splitting and combining hub of the interferometer.

[0047] Four fiber optic connectors are sealed and installed on the side wall of the mounting box 101: a first fiber optic connector 105, a second fiber optic connector 106, a third fiber optic connector 107, and a fourth fiber optic connector 108. These connectors are preferably standard fiber optic flanges or fiber optic collimator interfaces, and are equipped with locking and sealing structures.

[0048] The first fiber optic connector 105 is located inside the box, with one end connected to the input port of the circulator 102 via the second fiber optic cable 109, and the other end located outside the box is connected to an external light source via an armored patch cord.

[0049] The second fiber optic connector 106 is located inside the enclosure and connected to the output port of the circulator 102 via the third fiber optic cable 110. The other end of the connector is located outside the enclosure and connected to an external spectrometer via an armored jumper cable.

[0050] The third fiber optic connector 107 is located inside the enclosure and connected to an output port of the coupler 103 via a fourth fiber optic cable 111. The other end of the connector is located outside the enclosure and connected to the input of the reference arm module 200 via an armored patch cord.

[0051] The fourth fiber optic connector 108 is located inside the box, with one end connected to the other output port of the coupler 103 via the fifth fiber optic cable 112, and the other end located outside the box is connected to the input end of the sample arm module 300 via an armored jumper cable.

[0052] Crucially, the first optical fiber 104, the second optical fiber 109, the third optical fiber 110, the fourth optical fiber 111, and the fifth optical fiber 112 are all securely fixed inside the fixing box 101. Specific fixing methods include, but are not limited to, using optical fiber holders, cable trays, or multi-point bonding with the box substrate using low-stress UV-curable adhesive. The purpose is to eliminate free dangling sections of the optical fibers inside the box, forming a rigid integral with the fixing box 101, thereby isolating these core optical fibers from external vibrations.

[0053] Specifically, the circulator 102 is a three-port optical circulator, with the optical signal transmission direction from port 1 to port 2 and from port 2 to port 3. The coupler 103 is a 1×2 fiber optic coupler with ports 4, 5, and 6.

[0054] The specific port connections and optical path routing are as follows: The probe light from an external light source enters port 1 of the circulator 102 sequentially via the first fiber optic connector 105 and the second fiber optic cable 109, and exits from port 2 of the circulator 102. The light exiting from port 2 of the circulator 102 is transmitted to port 4 of the coupler 103 via the first fiber optic cable 104. The probe light is split within the coupler 103 into two beams: one beam serves as a reference beam, entering the reference arm module 200 via port 5 of the coupler 103, the fourth fiber optic cable 111, and the third fiber optic connector 107; the other beam serves as a sample beam, entering the sample arm module 300 via port 6 of the coupler 103, the fifth fiber optic cable 112, and the fourth fiber optic connector 108.

[0055] The reference light returning from the reference arm module 200 enters the coupler 103 via the third fiber connector 107, the fourth fiber 111, and port 5 of the coupler 103. The sample light returning from the sample arm module 300 enters the coupler 103 via the fourth fiber connector 108, the fifth fiber 112, and port 6 of the coupler 103. The reference light and sample light converge and interfere within the coupler 103. The resulting interference signal is transmitted in the reverse direction from port 4 of the coupler 103 and the first fiber 104 to port 2 of the circulator 102. This interference signal follows the unidirectional transmission characteristic of the circulator, entering from port 2 and exiting from port 3. Finally, the interference signal is sequentially exported to an external spectrometer via the third fiber 110 and the second fiber connector 106.

[0056] Through the aforementioned clearly defined port connections, the circulator 102 achieves the function of isolating and directionally transmitting the input light and the returned interference signal of the light source in the optical path, ensuring the normal operation of the optical path.

[0057] The core function of the mounting box 101 is to provide a rigid, sealed, and vibration-isolated physical environment for the core optical components such as the circulator 102 and coupler 103, as well as the connecting optical fibers between them. By securely encapsulating and fixing all the optical fibers inside the box, fiber deformation and sway caused by external mechanical vibration or airflow disturbances can be effectively suppressed. This design physically minimizes the random optical path variation in the common optical path of the two arms of the interferometer, thereby significantly reducing the phase noise introduced by it, ensuring the stability and signal-to-noise ratio of the coherent imaging signal, and laying a reliable measurement foundation for subsequent high-precision laser processing calibration.

[0058] Please refer to the above as well. Figures 1 to 10 In one embodiment of this application, a removable sealing cover 113 is installed on the side of the fixed box 101 to achieve airtight sealing of the interior of the fixed box 101. To further enhance the protection of core optical components and the adjustability of system performance, the sealing cover 113 is designed with a dedicated functional fluid management interface.

[0059] Specifically, please combine Figure 10 The sealing cap 113 has two through holes: an injection hole 114 and a vent hole 115. The injection hole 114 is located at the bottom of the sealing cap 113 (i.e., a relatively low position after installation), while the vent hole 115 is located at the top of the sealing cap 113 (i.e., a relatively high position after installation). This high-low arrangement conforms to the natural laws of functional fluid injection and gas venting. Both the injection hole 114 and the vent hole 115 are internally threaded and are respectively connected to a removable sealing plug 116 via threaded sealing. A sealing ring can be fitted to the end of the sealing plug 116 to ensure airtightness after tightening.

[0060] The injection port 114 and vent port 115 provide a controllable channel for injecting or extracting a specific medium into the sealed cavity of the fixed box 101. When the device is finally commissioned and requires long-term stable operation, a sealing operation can be performed. First, keep the sealing plug 116 on the vent port 115 loose or remove it first. Then, connect the output interface of the injection device (such as a dedicated injection gun) to the injection port 114 and inject a specific functional fluid medium, such as a high-damping gel for cushioning vibrations, into the fixed box 101 through this port. During injection, air inside the box will be smoothly expelled from the higher-positioned vent port 115, avoiding air bubble residue. After the functional fluid fills the internal space of the box and steadily overflows from the vent port 115, first tighten the sealing plug 116 of the vent port 115, then disconnect the injection device and immediately tighten the sealing plug 116 of the injection port 114, thereby completely sealing the functional fluid inside the fixed box 101, immersing the core optical components such as the circulator 102, coupler 103, and the first to fifth optical fibers in the functional fluid.

[0061] The combination of injection hole 114 and vent hole 115 enables active and controllable encapsulation of the core optical path environment of the fixed module 100. The injected functional fluid (especially high-damping gel) can form a comprehensive wrapping and support for the optical fiber and micro optical components, which can further effectively suppress and attenuate the transmission of residual mechanical vibrations within the enclosure, fundamentally reducing the micro-bending and jitter of the optical fiber.

[0062] Please refer to the above as well. Figures 1 to 10 In one embodiment of this application, the reference arm module 200 includes a reference arm mounting box 201. The reference arm mounting box 201 is tightly fixed to the side of the fixed box 101 using rigid connectors such as bolts and flanges, ensuring no relative displacement between the two and forming a stable mechanical whole. The reference arm mounting box 201 is also preferably made of a high-rigidity, low-thermal-expansion-coefficient material, and its interior can be treated with an anti-glare process to provide a stable optical environment.

[0063] Inside the reference arm mounting box 201, a first collimating mirror 202 and a first reflecting mirror 203 are sequentially installed along the optical path, with their optical axes corresponding. The first collimating mirror 202 is precisely aligned and connected to the end of the third fiber optic connector 107 located outside the fixed box 101 (i.e., the input end of the reference arm's optical path) via an armored fiber optic patch cord or directly through a fiber optic collimator interface. Its function is to collimate the divergent probe light emitted from the fiber optic cable from the fixed module 100 into a parallel beam. The first reflecting mirror 203 is preferably a high-reflectivity plane mirror, installed inside the reference arm mounting box 201. An optical path adjustment mechanism 500 is provided between the first collimating mirror 202 and the first reflecting mirror 203 to adjust the optical path length of the reference arm.

[0064] During operation, the reference light emitted from coupler 103 of fixed module 100 enters reference arm module 200 via fourth fiber 111, third fiber connector 107, and connecting jumper. After being collimated into parallel light by first collimating mirror 202, it is directed towards first reflecting mirror 203. Reflected by first reflecting mirror 203, the light returns along its original path, is coupled back to the fiber optic cable via first collimating mirror 202, and then transmitted back to coupler 103 of fixed module 100 via third fiber connector 107. The core function of this module is to provide a precisely adjustable and highly stable reference optical path. Its stability directly determines the reference accuracy of the entire interferometry system. By integrating the first collimating mirror 202 and first reflecting mirror 203 and their adjustment mechanism into a separate mounting box rigidly connected to the fixed module, the influence of environmental disturbances on this section of the free-space optical path can be isolated. Simultaneously, the rigid connection to the fixed module ensures the overall rigidity of the common structure of the two arms of the interferometer, thus jointly guaranteeing the phase stability and repeatability of the interference signal.

[0065] Please refer to the above as well. Figures 1 to 10In one specific embodiment of this application, the optical path adjustment mechanism 500 between the first collimating mirror 202 and the first reflecting mirror 203 includes a third reflecting mirror 501. The third reflecting mirror 501 is fixedly installed inside the reference arm mounting box 201. In the outgoing optical path of the first collimating mirror 202, the parallel light beam first enters the fixed third reflecting mirror 501. In the reflected optical path of the third reflecting mirror 501, an adjustment assembly movable along the optical axis is installed inside the reference arm mounting box 201. This assembly includes a slide rail 502 fixed inside the reference arm mounting box 201 and a first reflecting mirror seat 503 slidably connected to the slide rail 502. An adjusting screw 504 is rotatably connected to the side wall of the reference arm mounting box 201 via a bearing. The adjusting screw 504 and the threaded block or nut fixed on the first reflecting mirror seat 503 form a threaded transmission pair. An adjusting knob 505 is fixedly installed at one end of the adjusting screw 504 extending outward from the reference arm mounting box 201. The adjustment knob 505 can be manually or by a precision motor to rotate the adjustment screw 504, thereby driving the first reflector mount 503 to make high-precision linear motion along the slide rail 502.

[0066] To achieve a sufficiently long optical path adjustment range within a limited space, the optical path is designed as a folded path within the adjustment assembly. A fourth reflector 507 is mounted on the first reflector mount 503, corresponding to the reflection direction of the third reflector 501. Inside the reference arm mounting box 201, a second reflector mount 506 is fixedly mounted relative to the first reflector mount 503. A fifth reflector 508 is mounted on this second reflector mount 506, directly opposite the fourth reflector 507. Finally, a sixth reflector 509 is mounted on the first reflector mount 503, corresponding to the reflection direction of the fifth reflector 508. The first reflector 203 is mounted on the inner wall of the reference arm mounting box 201 and is located on the reflected optical path of the sixth reflector 509.

[0067] During the work process, such as Figure 6 As shown, the parallel light emitted from the first collimating mirror 202 is first reflected by the fixed third reflecting mirror 501 to the fourth reflecting mirror 507 on the movable first reflecting mirror mount 503. Subsequently, the beam is reflected sequentially by the fourth reflecting mirror 507 to the fixed fifth reflecting mirror 508, then by the fifth reflecting mirror 508 back to the sixth reflecting mirror 509 on the movable assembly, and finally by the sixth reflecting mirror 509 back to the first reflecting mirror 203. After reflection by the first reflecting mirror 203, the beam returns along the original folded path and is finally coupled back to the optical fiber via the first collimating mirror 202. When the rotating adjustment knob 505 drives the first reflecting mirror mount 503 to move along the slide rail 502, the physical path length of the entire folded optical path, especially the moving part from the fourth reflecting mirror 507 to the sixth reflecting mirror 509, changes accordingly, thereby achieving precise and continuous adjustment of the optical path of the reference arm.

[0068] The core function of this module is to provide a highly stable reference optical path with precisely adjustable length. Its stability directly determines the reference accuracy of the entire interferometry system. By integrating the optical path adjustment mechanism and core optical components into a separate mounting box rigidly connected to the fixed module, the influence of environmental disturbances on this section of the free-space optical path can be effectively isolated. Simultaneously, the compact folded optical path design reduces the overall size of the module while ensuring a large adjustment range. The rigid connection to the fixed module ensures the overall rigidity of the common structure of the two arms of the interferometer, thereby jointly guaranteeing the phase stability and repeatability of the interference signal.

[0069] Please refer to the above as well. Figures 1 to 10 In one embodiment of this application, a first angle adjustment mechanism 600 for finely adjusting the angle of the first reflector 203 is installed on the reference arm mounting box 201. This mechanism provides a high-precision, backlash-free two-dimensional angle fine-tuning solution.

[0070] Specifically, please combine Figure 7 The first angle adjustment mechanism 600 includes three plates stacked along the optical axis (Z-axis): a first fixed mounting plate 601, a first direction adjustment plate 602, and a second direction adjustment plate 603. The first fixed mounting plate 601 is firmly fixed to the inner wall of the reference arm mounting box 201 by screws, serving as the base of the entire adjustment mechanism.

[0071] The first direction adjustment plate 602 is connected to the side of the first fixed mounting plate 601 via a first elastic connection 604. This first elastic connection 604 is preferably a thin-walled flexible hinge formed by precision wire cutting or etching, with its elastic deformation direction along the X-axis. Similarly, the second direction adjustment plate 603 is connected to the side of the first direction adjustment plate 602 via a second elastic connection 605, with its elastic deformation direction along the Y-axis. This orthogonal elastic hinge design allows the two adjustment plates to deflect at minute angles around different axes. The first reflector 203 is fixedly mounted on the uppermost second direction adjustment plate 603 via a mirror frame. To achieve precise actuation, a first adjustment screw 606 is threaded onto the first fixed mounting plate 601, on the side furthest from the first elastic connection 604. The inner end of this screw is rolled with a first ball 607 via a small bearing or precision ball-and-socket structure, the spherical surface of which abuts against the corresponding plane of the first direction adjustment plate 602. Similarly, on the first direction adjustment plate 602, on the side away from the second elastic connection part 605, a second adjustment screw 608 is threadedly connected, and a second ball 609 is rolledly connected to its inner end, which abuts against the second direction adjustment plate 603.

[0072] During operation, the mechanism utilizes the restoring force of the elastic hinge as a preload. When adjusting the pitch angle of the first reflector 203 around the X-axis, a tool is used to fine-tune the first adjusting screw 606. Screwing the screw pushes the first direction adjusting plate 602 via the first ball bearing 607, causing it to elastically bend around the first elastic connection 604 (X-axis direction hinge), thereby causing the entire upper assembly (including the second direction adjusting plate 603 and the first reflector 203) to deflect around the X-axis. Similarly, when adjusting the yaw angle around the Y-axis, the second adjusting screw 608 is fine-tuned. It directly pushes the second direction adjusting plate 603 via the second ball bearing 609, causing it to elastically bend around the second elastic connection 605 (Y-axis direction hinge), thus individually changing the angle of the first reflector 203 around the Y-axis. The ball bearing connection design converts the rotational motion of the screw into a pure thrust on the adjusting plate, greatly reducing friction and backlash. After adjustment, the inherent stiffness of the elastic hinge can reliably maintain the set angle, ensuring long-term stability.

[0073] The first angle adjustment mechanism 600 provides high-precision angle alignment capability for the first reflecting mirror 203 reflected at the end of the reference arm. By finely adjusting the angle of this reflecting mirror, spatial mode matching and wavefront conjugation can be ensured at the coupler 103 between the beam returning from the reference arm and the beam returning from the sample arm. This is crucial for obtaining a high-contrast, low-noise interference signal. Its compact, stacked design saves space and works in conjunction with the aforementioned optical path adjustment mechanism 500 to jointly ensure the accuracy and stability of the reference optical path.

[0074] Please refer to the above as well. Figures 1 to 10 In one embodiment of this application, the sample arm module 300 includes a sample arm mounting box 301. One side of the sample arm mounting box 301 is firmly connected to the fixed box 101 via rigid connectors such as flanges and fastening bolts, while the other side is rigidly connected to the housing or base of the laser processing equipment 400. This rigid connection of the fixed module 100, the sample arm module 300, and the laser processing equipment 400 ensures that a unified rigid mechanical structure is formed from the interferometer core to the processing execution end, maximizing the suppression of relative displacement and vibration between modules and providing a fundamental guarantee for achieving high-precision calibration. The sample arm mounting box 301 is preferably made of a material with high rigidity and a low coefficient of thermal expansion, and its interior can be treated with matte finish and sealing.

[0075] Inside the sample arm mounting box 301, corresponding second collimating mirrors 302 and second reflecting mirrors 303 are installed along the optical path. The second collimating mirror 302 is precisely aligned and connected to the end of the fourth fiber optic connector 108 located outside the fixed box 101 via a fiber optic collimator interface. Its function is to collimate the sample light emitted from the coupler 103 of the fixed module 100 and transmitted through the fifth fiber optic cable 112 into a parallel beam. The second reflecting mirror 303 is preferably a high-reflectivity plane mirror, and its installation angle is precisely set to deflect the parallel beam emitted from the second collimating mirror 302 by 90°, ensuring it accurately enters the entrance aperture of the laser processing equipment 400 with which it is connected.

[0076] During operation, the sample light emitted from the fixed module 100 enters the sample arm module 300 via the fifth optical fiber 112 and the fourth optical fiber connector 108, where it is collimated into parallel light by the second collimating mirror 302. This parallel light is reflected by the second reflecting mirror 303 and then enters the internal optical path of the laser processing equipment 400. Inside the laser processing equipment 400, the probe light is combined with the processing laser through a beam combiner (not shown in the figure), and then both are scanned and deflected by the galvanometer 401, finally focused onto the surface of the workpiece by the field mirror 402. The sample light reflected / scattered from the workpiece surface returns along the original path, passing sequentially through the field mirror 402, the galvanometer 401, the beam combiner, and the incident light aperture of the laser processing equipment 400, before re-entering the sample arm module 300. It is then reflected by the second reflecting mirror 303, coupled by the second collimating mirror 302, and transmitted back to the coupler 103 of the fixed module 100 via the fourth optical fiber connector 108.

[0077] The core function of the sample arm module 300 is to act as an "optical bridge" between the stable interferometer core (fixed module 100) and the processing execution unit (laser processing equipment 400) containing moving parts (galvanometer 401). Its rigid housing structure and precise internal optical component mounting ensure extremely high mechanical and thermal stability of this connecting optical path. By rigidly connecting both ends of the sample arm module 300 to the fixed module 100 and the laser processing equipment 400 respectively, the entire sample arm optical path from the coupler 103 to the workpiece surface is solidified to the maximum extent, thereby minimizing the adverse effects of external environmental vibrations and the laser processing equipment's own vibrations on interferometric measurements and ensuring the long-term stability and repeatability of the measurement beam direction.

[0078] Please refer to the above as well. Figures 1 to 10In one embodiment of this application, a position adjustment mechanism 700 for finely adjusting the axial position of the second collimating lens 302 is installed on the sample arm mounting box 301. This mechanism provides the ability to make precise and stable adjustments in the optical axis direction (Z-axis) to ensure that the probe light emitted from the sample arm can be accurately and efficiently coupled into the optical path of the subsequent laser processing equipment.

[0079] Specifically, please combine Figure 8 The position adjustment mechanism 700 includes an outer cylinder 701. One end of the outer cylinder 701 is fixedly mounted on the corresponding mounting surface of the sample arm mounting box 301 by screws, and the other end is also fixedly mounted on the side wall of the fixing box 101 (specifically, the interface panel corresponding to the fourth fiber optic connector 108) by screws. This double-end rigid fixing design makes the position adjustment mechanism 700 itself a stable mechanical component connecting the fixing module 100 and the sample arm module 300, enhancing the rigidity of the overall structure.

[0080] Inside the outer cylinder 701, an inner cylinder 702 is coaxially fixedly installed. A lens barrel 703 is slidably connected to the inner bore of the inner cylinder 702. The lens of the second collimating lens 302 is precisely press-fitted or glued to the inside of the lens barrel 703. An adjustment groove 704 is formed circumferentially on the outer circumferential surface of the lens barrel 703.

[0081] An adjusting disc 705 is rotatably connected to the side wall of the inner cylinder 702 via a damped bearing. An eccentric pin 706 is fixedly connected to the end face of the adjusting disc 705 extending into the inner cylinder 702. The eccentric pin 706 is precisely inserted into the adjusting groove 704 on the lens barrel 703, with its axis parallel to the rotation axis of the adjusting disc 705 but with a certain eccentricity. A driving groove 707 is formed on the outer end face of the adjusting disc 705. The driving groove 707 can be configured as an internal hexagonal, slotted, Phillips, or dedicated polygonal groove to allow rotation via a tool. A clearance hole 708 is formed on the outer cylinder 701 corresponding to the position of the adjusting disc 705 to allow tools to be inserted for operation.

[0082] During operation, the position adjustment mechanism 700 utilizes the principle of "converting eccentric rotation into linear motion." When it is necessary to adjust the axial position of the second collimating lens 302 to optimize the collimation optical path or compensate for assembly tolerances, a special tool is inserted into the drive groove 707 of the adjustment disk 705 through the clearance hole 708. Rotating the adjustment disk 705 forces the eccentric pin 706 to revolve around its own axis, as the eccentric pin 706 is inserted into the axial adjustment groove 704 of the lens barrel 703. This revolve motion, constrained by the adjustment groove 704, is converted into a pushing or pulling force on the lens barrel 703 along its axial direction, thereby driving the entire lens barrel 703, along with the second collimating lens 302 inside, to perform precise axial sliding within the inner cylinder 702. The design of the adjustment groove 704 allows this axial movement while constraining the circumferential rotation of the lens barrel 703, ensuring the linearity and stability of the adjustment. Once rotated to the desired position to achieve optimal collimation and coupling of the beam, the inherent friction between the lens barrel 703 and the inner barrel 702 can maintain its fixed position.

[0083] The position adjustment mechanism 700 provides a crucial fine-tuning means for achieving high-precision spatial mode matching between the beam emitted from the sample arm and the incident aperture of the subsequent laser processing equipment. By precisely adjusting the axial position of the second collimating mirror 302, its relative position to the end face of the input fiber can be optimized, ensuring that the light emitted from the fiber is perfectly collimated, and that this collimated beam enters the laser processing equipment 400 after being deflected by the second reflecting mirror 303 at the optimal angle and position. This is essential for maximizing light energy utilization, ensuring beam quality, and ultimately achieving high signal-to-noise ratio interferometric measurements. Its rigid cylindrical structure and precise sliding fit provide adjustment functionality while ensuring the long-term stability and vibration resistance of the adjusted optical path.

[0084] Please refer to the above as well. Figures 1 to 10 In one embodiment of this application, a second angle adjustment mechanism 800 for finely adjusting the angle of the second reflector 303 is installed on the sample arm mounting box 301. This mechanism is similar in principle to the aforementioned first angle adjustment mechanism 600, providing a high-precision and high-stability two-dimensional angle fine-tuning solution, which is key to ensuring precise alignment between the sample arm's emitted beam and the laser processing equipment 400.

[0085] Specifically, please combine Figure 9 The structure of the second angle adjustment mechanism 800 includes a second fixed mounting plate 801, a third direction adjustment plate 802, and a fourth direction adjustment plate 803 stacked along the optical axis (Z-axis). The second fixed mounting plate 801 is firmly fixed to the inner wall of the sample arm mounting box 301 by screws, serving as a mounting base.

[0086] The third-direction adjusting plate 802 is connected to the side of the second fixed mounting plate 801 via a third elastic connecting part 804, which is a thin-walled flexible hinge designed in the X-axis direction. The fourth-direction adjusting plate 803 is connected to the side of the third-direction adjusting plate 802 via a fourth elastic connecting part 805, with its flexible hinge direction along the Y-axis. This orthogonal flexible hinge layout allows the two adjusting plates to achieve elastic deflection of a very small angle around different axes, without mechanical friction or gaps.

[0087] The third reflector mount 806 is fixedly installed on the fourth direction adjustment plate 803, and the second reflector 303 is finally installed on the third reflector mount 806, thereby realizing the linkage with the adjustment mechanism.

[0088] To achieve precise driving and adjustment, a third adjusting screw 807 is threadedly connected to the second fixed mounting plate 801 on the side away from the third elastic connecting part 804. Its inner end is rolled with a third ball bearing 808 via a precision structure, the spherical surface of which abuts against the back of the third directional adjusting plate 802. Similarly, on the third directional adjusting plate 802, a fourth adjusting screw 809 is threadedly connected to the side away from the fourth elastic connecting part 805, its inner end being rolled with a fourth ball bearing 810, which abuts against the fourth directional adjusting plate 803.

[0089] During operation, the second angle adjustment mechanism 800 utilizes the elastic restoring force of the flexible hinge as a self-restoring preload, achieving zero backlash and high-resolution adjustment. When it is necessary to adjust the yaw angle of the second reflector 303 around the X-axis, the third adjustment screw 807 is rotated using a fine-tuning tool. The screw's rotation pushes the third directional adjustment plate 802 via the third ball bearing 808, causing it to undergo a slight elastic bend around the third elastic connection 804 (X-axis hinge). Since the fourth directional adjustment plate 803 and the third reflector mount 806 are both connected to the third directional adjustment plate 802 via the fourth elastic connection 805, the entire upper assembly (including the second reflector 303) will synchronously deflect around the X-axis, thereby changing the beam's exit angle in the horizontal direction (X-axis related). Similarly, when adjusting the pitch angle around the Y-axis, the fourth adjusting screw 809 is fine-tuned. This screw, via the fourth ball bearing 810, directly pushes the fourth direction adjusting plate 803, causing it to bend independently around the fourth elastic connection 805 (Y-axis hinge). This independently changes the angle of the second reflector 303 around the Y-axis, thereby controlling the beam's emission angle in the vertical direction (Y-axis related). The ball bearing connection converts the screw's rotational motion into pure thrust, greatly reducing friction and return errors. After adjustment, the overall structure maintains angular stability due to the inherent stiffness of the flexible hinge, exhibiting strong vibration resistance.

[0090] The second angle adjustment mechanism 800 ensures that the collimated probe beam emitted from the sample arm module 300 can enter the predetermined entrance aperture of the laser processing equipment 400 with extremely high angular accuracy. This is a crucial prerequisite for achieving precise co-pathing and perfect spatial mode matching between the subsequent probe beam and the processing laser. Its compact stacked design and frictionless adjustment mechanism provide nanometer-level angular alignment capability while ensuring the long-term repeatability and stability of the adjusted optical path direction, fundamentally improving the initial assembly accuracy and long-term operational reliability of the entire laser processing calibration device.

[0091] Example 2

[0092] A laser processing calibration method based on coherent imaging, applied to the laser processing calibration device based on coherent imaging described in Example 1, includes: S1. System Integration and Optical Path Stabilization: S11. The fixed module 100, the reference arm module 200, and the sample arm module 300 are rigidly connected into a whole by bolts, flanges, and other connecting parts, and the output end of the sample arm module 300 is rigidly connected to the optical head of the laser processing equipment 400 to form a stable overall structure from the core of the interferometer to the processing end.

[0093] S12. Fix the first optical fiber 104, the second optical fiber 109, the third optical fiber 110, the fourth optical fiber 111 and the fifth optical fiber 112 in the fixing box 101, so that the optical path of the first optical fiber 104, the second optical fiber 109, the third optical fiber 110, the fourth optical fiber 111 and the fifth optical fiber 112 remains physically stable and their free suspension sections are eliminated.

[0094] S2, Coherent Imaging and 3D Measurement: S21. Start the light source. The probe light generated by the light source is split into a reference beam and a sample beam by the fixing module 100. The reference beam enters the reference arm module 200 through the fourth optical fiber 111, and the sample beam enters the sample arm module 300 through the fifth optical fiber 112.

[0095] S22. The reference beam entering the reference arm module 200 is reflected back along the original path by the first reflecting mirror 203. The sample beam entering the sample arm module 300 is deflected by the second reflecting mirror 303 and then enters the laser processing equipment 400. After being combined with the processing laser, it is scanned by the galvanometer 401 and focused by the field mirror 402, irradiating the surface and interior of the workpiece to be processed, and is reflected back along the original path.

[0096] S23. After the reference beam and sample beam return, they converge and interfere at the coupler 103 within the fixed module 100. The resulting interference light is guided to the spectrometer via the circulator 102. The spectrometer acquires the interference spectral signal distributed with wavelength, and reconstructs a high-axial-resolution three-dimensional topographic image of the target area of ​​the workpiece to be processed using algorithms such as Fourier transform.

[0097] S3. Machining coordinate extraction and positioning: S31. Based on the three-dimensional topography image obtained in S2, the three-dimensional spatial coordinates (X,Y,Z) of the features to be processed (such as cutting contours, drilling centers, carving area boundaries, etc.) in the OCT imaging coordinate system are accurately extracted using image processing algorithms.

[0098] S32. Based on the extracted coordinates, the control system drives the galvanometer 401 inside the laser processing equipment 400 to quickly and accurately position the focus of the beam shared by imaging and processing to the target coordinate point. This step relies on the accuracy of coordinate mapping guaranteed by the rigid structure of the entire device (especially the sample arm) and the stable optical path.

[0099] S4, Closed-loop control processing: S41. Start the processing laser (such as a femtosecond laser) of the laser processing equipment 400 and process the points located in step S3 according to preset parameters (power, pulse width, scanning speed, etc.).

[0100] S42. During the processing or after the processing of a single point, steps S2 and S3 can be repeated immediately or intermittently to perform rapid coherent imaging measurements on the newly processed area. The actual processed shape (such as pit depth, groove width, and surface roughness) measured in real time is compared with the preset target processed shape to generate an error signal containing information such as positional deviation and dimensional error.

[0101] S5. Dynamic calibration and compensation: S51. Based on the real-time error signal generated in step S42, dynamically adjust the processing parameters (such as laser energy, pulse frequency, and scanning speed) of the laser processing equipment 400 or correct the positioning coordinates of the subsequent processing points.

[0102] For example, if the measurement reveals insufficient drilling depth, additional pulses can be applied at that point or the laser energy at subsequent points can be increased; if a scribe line is found to be misaligned, the coordinates of the subsequent scanning path can be compensated and corrected. This closed-loop process of "measurement, processing, in-machine inspection, and feedback compensation" continues until the entire processing task is completed, thereby achieving real-time online calibration and proactive error compensation for the processing process, ensuring high precision and high consistency of the final processing results.

[0103] Optionally, in step S1, the first optical fiber 104, the second optical fiber 109, the third optical fiber 110, the fourth optical fiber 111, and the fifth optical fiber 112 are fixed by injecting a functional fluid with specific viscosity, high thermal conductivity, and optical compatibility into the fixing box 101 until the internal optical fibers are completely submerged, and then the fixing box 101 is sealed. This functional fluid can further suppress residual vibration and improve heat dissipation inside the box, thereby physically locking the optical path of the core optical fiber and minimizing random optical path variations introduced by vibration and thermal drift.

[0104] Optionally, in one specific embodiment of this application, the functional fluid is intended to provide vibration damping, thermal management, and optical protection for optical components and optical fibers within the mounting box 101. Its core is a specially formulated high-purity, low-viscosity methyl silicone oil and nano-alumina composite fluid, or a high-transmittance, high-thermal-conductivity silicone gel. Specific implementation schemes are as follows: Option 1: Nanoparticle-enhanced silicone oil-based functional fluid High-purity dimethyl silicone oil with a viscosity between 10 cSt and 100 cSt (25°C) is used. This base oil exhibits excellent light transmittance, low volatility, and good chemical stability. Spherical alumina (Al₂O₃) nanoparticles with a particle size of 20 nm to 50 nm are uniformly dispersed in the base silicone oil. The addition amount of nanoparticles is controlled between 1% and 5% to ensure that the fluid significantly improves its thermal conductivity while maintaining viscosity and flowability. With this configuration, the thermal conductivity of the fluid can be increased from approximately 0.1 W / (m·K) of the base silicone oil to 0.15-0.25 W / (m·K). Moreover, by precisely controlling the concentration of nanoparticles and selecting a specific type of silicone oil, the refractive index of the functional fluid can be adjusted to be highly matched (with a difference of less than 0.01) with the refractive index of the optical fiber cladding (typically around 1.46) and the glass substrate of the optical components in the mounting box (such as couplers and circulators), thereby minimizing Fresnel reflection loss at the fluid-component interface. The fluid in this configuration has a certain viscosity, which can form viscous damping on the optical fibers and micro-optical components suspended in it, effectively absorbing and attenuating high-frequency mechanical vibration energy and suppressing the micro-bending and shaking of the optical fibers.

[0105] Option 2: Curable optical silicone gel Base material: A two-component addition-type optical silicone gel is used. Before mixing and curing, this material is a low-viscosity liquid, facilitating pouring; after curing, it forms a soft gel. The cured gel exhibits extremely high transmittance in the probe light band, and its refractive index is adjustable, making it easy to match with optical fibers. Furthermore, by adding an appropriate amount of micron-sized boron nitride and other thermally conductive fillers, its thermal conductivity can reach over 0.2 W / (m·K), which is beneficial for uniform heat dissipation. Moreover, the cured gel is a soft elastomer that can completely encapsulate and "lock" the optical fiber and components in a fixed position, providing strong vibration isolation and mechanical buffering, while preventing damage to components due to stress concentration.

[0106] By injecting the functional fluid configured above, "active stabilization" of the core optical path of the fixed module 100 is achieved. The fluid-based approach in Option 1 focuses on fluidity and continuous heat dissipation, suitable for applications requiring long-term operation and high temperature control. The gel-based approach in Option 2 provides ultimate vibration suppression and physical fixation, suitable for environments with extremely stringent vibration resistance requirements. Both significantly improve the phase stability of the interferometer core and reduce system noise, which are key auxiliary technical features for achieving high-precision, high-repeatability laser processing calibration in this application.

[0107] This method fully utilizes the mechanical and optical stability of the device provided in Example 1. Step S1 fundamentally suppresses vibration noise, enabling step S2 to obtain a stable and clear 3D image, providing a reliable basis for precise positioning. Closed-loop machining and compensation based on this stable benchmark transforms the device's static stability into dynamic precision control of the machining process, effectively overcoming the degradation in machining quality caused by environmental disturbances, thermal drift, and accumulated errors in traditional methods.

[0108] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A laser processing calibration device based on coherent imaging, characterized in that, The system includes a fixed module (100), which is fixedly connected to a reference arm module (200) and a sample arm module (300). The sample arm module (300) is fixedly connected to a laser processing device (400), which is equipped with a galvanometer (401) and a field lens (402). The fixed module (100) includes a fixed box (101), which houses a beam splitter. The side wall of the fixed box (101) is equipped with a first fiber optic connector (105), a second fiber optic connector (106), a third fiber optic connector (107), and a fourth fiber optic connector (108). One end of the first fiber optic connector (105) is connected to the beam splitter via a second fiber optic cable (109). The second fiber optic connector (106) is connected to the light source; one end of the second fiber optic connector (106) is connected to the spectrometer; one end of the third fiber optic connector (107) is connected to the spectrometer; one end of the third fiber optic connector (107) is connected to the spectrometer; one end of the third fiber optic connector (107) is connected to the reference arm module (200); one end of the fourth fiber optic connector (108) is connected to the spectrometer; one end of the fourth fiber optic connector (108) is connected to the sample arm module (300); the spectrometer, the second fiber optic connector (109), the third fiber optic connector (110), the fourth fiber optic connector (111), and the fifth fiber optic connector (112) are all fixed inside the fixed box (101).

2. The laser processing calibration device based on coherent imaging according to claim 1, characterized in that: The reference arm module (200) includes a reference arm mounting box (201), which is fixedly mounted on the fixed box (101). The reference arm mounting box (201) is equipped with a first collimating mirror (202) and a first reflecting mirror (203) that correspond to each other. The first collimating mirror (202) is connected to the third fiber optic connector (107).

3. The laser processing calibration device based on coherent imaging according to claim 1, characterized in that: The sample arm module (300) includes a sample arm mounting box (301). One side of the sample arm mounting box (301) is fixedly connected to the fixed box (101), and the other side of the sample arm mounting box (301) is fixedly connected to the laser processing equipment (400). A second collimating mirror (302) and a second reflecting mirror (303) corresponding to each other are installed inside the sample arm mounting box (301). The second collimating mirror (302) is correspondingly connected to the fourth fiber optic connector (108); the second reflecting mirror (303) is correspondingly connected to the laser processing equipment (400).

4. The laser processing calibration device based on coherent imaging according to claim 2, characterized in that: An optical path adjustment mechanism (500) is provided between the first collimating mirror (202) and the first reflecting mirror (203).

5. The laser processing calibration device based on coherent imaging according to claim 2, characterized in that: The reference arm mounting box (201) is equipped with a first angle adjustment mechanism (600) for adjusting the angle of the first reflector (203).

6. The laser processing calibration device based on coherent imaging according to claim 3, characterized in that: The sample arm mounting box (301) is equipped with a position adjustment mechanism (700) for adjusting the second collimating lens (302).

7. The laser processing calibration device based on coherent imaging according to claim 3, characterized in that: The sample arm mounting box (301) is equipped with a second angle adjustment mechanism (800) for adjusting the angle of the second reflector (303).

8. The laser processing calibration device based on coherent imaging according to claim 1, characterized in that: The optical splitter includes a circulator (102) and a coupler (103). A first optical fiber (104) is connected between the circulator (102) and the coupler (103). The circulator (102), the coupler (103), and the first optical fiber (104) are all fixedly installed inside the fixed box (101).

9. A laser processing calibration method based on coherent imaging, characterized in that, The laser processing calibration device based on coherent imaging as described in claim 1 includes: S1. System Integration and Optical Path Stabilization: S11. The fixed module (100), the reference arm module (200), and the sample arm module (300) are rigidly connected into a whole, and the sample arm module (300) is rigidly connected to the laser processing equipment (400); S12. Fix the first optical fiber (104), the second optical fiber (109), the third optical fiber (110), the fourth optical fiber (111), and the fifth optical fiber (112) in the fixed box (101) so that the optical path length of the first optical fiber (104), the second optical fiber (109), the third optical fiber (110), the fourth optical fiber (111), and the fifth optical fiber (112) remains physically stable. S2, Coherent Imaging and 3D Measurement: S21. Start the light source. The probe light generated by the light source is split into a reference beam and a sample beam by the fixed module (100), and enters the reference arm module (200) and the sample arm module (300) respectively. S22. The reference beam is reflected by the first reflecting mirror (203), and the sample beam is emitted from the sample arm module (300) and the laser processing equipment (400) and then reflected after irradiating the sample surface; S23. After the reference beam and the sample beam return, they interfere within the fixed module (100). The interference spectrum is obtained by the spectrometer and a three-dimensional topographic image of the target area of ​​the workpiece to be processed is reconstructed. S3. Machining coordinate extraction and positioning: S31. Based on the three-dimensional topography image obtained in S2, extract the three-dimensional spatial coordinates of the features to be processed in the imaging coordinate system; S32. Control the galvanometer (401) and field mirror (402) installed inside the laser processing equipment (400) to position the focal point of the beam shared by imaging and processing to the coordinates; S4, Closed-loop control processing: S41. Start the processing laser of the laser processing equipment (400) to process the points located in step S3; S42. During the processing, repeat steps S2 and S3 to perform real-time coherent imaging measurement of the processing area, compare the measured actual processing morphology with the preset target morphology, and generate an error signal. S5. Dynamic calibration and compensation: S51. Based on the error signal generated in step S4, dynamically adjust the processing parameters of the laser processing equipment (400) to achieve closed-loop calibration and error compensation of the processing process.

10. The laser processing calibration method based on coherent imaging according to claim 9, characterized in that, In step S1, fixing the first optical fiber (104), the second optical fiber (109), the third optical fiber (110), the fourth optical fiber (111), and the fifth optical fiber (112) involves injecting a functional fluid with specific viscosity and thermal conductivity into the fixing box (101) so that the optical fibers inside the box are immersed in the functional fluid to suppress vibration and improve heat dissipation.

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