WO2022088533A1 - 分数傅里叶全息飞秒激光三维并行加工、监测***及方法 - Google Patents

分数傅里叶全息飞秒激光三维并行加工、监测***及方法 Download PDF

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WO2022088533A1
WO2022088533A1 PCT/CN2021/073318 CN2021073318W WO2022088533A1 WO 2022088533 A1 WO2022088533 A1 WO 2022088533A1 CN 2021073318 W CN2021073318 W CN 2021073318W WO 2022088533 A1 WO2022088533 A1 WO 2022088533A1
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fractional fourier
femtosecond laser
dimensional
light
parallel processing
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PCT/CN2021/073318
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English (en)
French (fr)
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孙树峰
王津
王萍萍
张丰云
王茜
邵晶
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青岛理工大学
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/062—Shaping the laser beam, e.g. by masks or multi-focusing by direct control of the laser beam
    • B23K26/0622—Shaping the laser beam, e.g. by masks or multi-focusing by direct control of the laser beam by shaping pulses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/04—Automatically aligning, aiming or focusing the laser beam, e.g. using the back-scattered light
    • B23K26/046—Automatically focusing the laser beam
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
    • B23K26/0643—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms comprising mirrors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
    • B23K26/0648—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms comprising lenses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/70—Auxiliary operations or equipment
    • B23K26/702—Auxiliary equipment

Definitions

  • the present disclosure relates to the fields of ultrafast laser precision processing technology and optical holography processing technology, in particular to a fractional Fourier holographic femtosecond laser three-dimensional parallel processing and monitoring system and method.
  • laser processing has flexible processing methods and is widely used.
  • processing methods not only can the target structure be processed by removing the material matrix, such as laser etching, laser drilling, laser cleaning, etc., but also can be applied to additive manufacturing to realize the preparation of complex structures, such as laser 3D printing, laser melting, etc.
  • processing materials not only opaque metal or ceramic materials that are difficult to handle by traditional means can be processed, but also the internal structure of transparent materials can be processed.
  • Holographic femtosecond laser processing provides a novel solution for three-dimensional scale and high processing efficiency due to its flexible and changeable light modulation properties.
  • some novel calculation methods of optical field modulation have emerged, which are mostly used in two-photon polymerization technology, and the preparation of three-dimensional structures completed by multi-layer two-dimensional pattern scanning and mobile platform.
  • three-dimensional laser spots are widely used in optical tweezers, two-photon polymerization, biomedicine, and surface microtexture preparation.
  • the inventors of the present disclosure found that the existing holographic femtosecond laser processing technology is limited by multi-dimensional scales, and cannot realize the processing of complex shapes and microstructures; and the existing processing methods cannot simply and quickly realize three-dimensional light field modulation, and the processing efficiency is low.
  • the present disclosure provides a fractional Fourier holographic femtosecond laser three-dimensional parallel processing and monitoring system and method, which overcomes the problems of multi-dimensional scale processing and low efficiency, and solves the problems of complex shape microstructure processing. It effectively improves the processing quality and processing efficiency of the three-dimensionally distributed microstructures, increases the processing efficiency to more than an order of magnitude, significantly shortens the processing time, and greatly improves the positional accuracy between the three-dimensionally distributed structures.
  • a first aspect of the present disclosure provides a fractional Fourier holography femtosecond laser three-dimensional parallel processing system.
  • a fractional Fourier holographic femtosecond laser three-dimensional parallel processing system comprising a spatial light modulator, a Fourier lens, a first lens, a first beam splitter and a first focusing objective lens;
  • the spatial light modulator is configured to receive a femtosecond laser beam and a fractional Fourier hologram, and to emit modulated multiplexed beams to a plurality of focal planes;
  • the light spot array is focused at a plurality of different depths in a specific processing position.
  • a laser is also included, and the laser is a near-infrared femtosecond laser.
  • it also includes a half-wave plate, a polarization cube and a beam expander, and the laser light emitted by the laser reaches the spatial light modulator after passing through the half-wave plate, the polarization cube and the beam expander in sequence.
  • a second aspect of the present disclosure provides a fractional Fourier holographic femtosecond laser three-dimensional parallel processing monitoring system.
  • a fractional Fourier holographic femtosecond laser three-dimensional parallel processing monitoring system comprising the parallel processing system described in the first aspect of the present disclosure, an LED white light source, a first collimating mirror, a second beam splitter, an infrared filter, a first Two lenses, the first CCD camera;
  • the light beam emitted by the LED white light source reaches the surface of the workpiece after passing through the first collimating mirror, the second beam splitter, the infrared filter and the first focusing objective lens in sequence;
  • the reflected light reaches the first CCD camera through the first focusing objective lens, the infrared filter, the second beam splitter and the second lens in sequence, and real-time monitoring of workpiece processing is performed according to the image received by the first CCD camera.
  • an optical interferometry system is also included;
  • the optical interferometric measurement system includes a coherent light source, a second collimating mirror, a third beam splitter, a reflector, a third lens, a second focusing objective lens and a second CCD camera, and the coherent light emitted by the coherent light source is sequentially collimated by the second lens
  • the mirror and the third beam splitter are divided into measurement light and reference light;
  • the measurement light is irradiated to the workpiece surface through the second focusing objective lens, and the interference light after the interference of the reflected light and the reference light reaches the second CCD camera through the third lens. According to the phase difference between the measurement light wave and the reference light wave, the workpiece surface profile and depth information are obtained.
  • it also includes a motion platform and a control terminal, the workpiece is set on the motion platform, the motion platform, the processing system and the monitoring system are all set on the optical platform, and the control terminal is respectively connected with the controller of the spatial light modulator. , the controller of the laser and the communication connection of the motion platform.
  • a third aspect of the present disclosure provides a fractional Fourier holography femtosecond laser three-dimensional parallel processing method.
  • a fractional Fourier holographic femtosecond laser three-dimensional parallel processing method using the fractional Fourier holographic femtosecond laser three-dimensional parallel processing monitoring system described in the second aspect of the present disclosure, includes the following steps:
  • the surface profile of the workpiece is measured by optical interferometry, and the collected interference image is processed to obtain the three-dimensional topography of the workpiece surface;
  • the three-dimensional lattice distribution and the target pattern are designed, and the three-dimensional fractional Fourier hologram is calculated by the iterative fractional Fourier transform method;
  • the obtained hologram is loaded into the spatial light modulator to reconstruct the 3D target focus image, the femtosecond laser beam is modulated into multiple beams, and the 3D spot focusing is completed in different focal planes in space;
  • the space spot array focuses the femtosecond laser at a specific processing position through a focusing objective lens, and performs three-dimensional parallel micro-machining on the surface of the workpiece.
  • the surface topography of the workpiece and the distribution, size and shape characteristics of the microstructure determine the location and depth information of the microstructure, and design the three-dimensional lattice distribution and target pattern;
  • the iterative fractional Fourier transform method specifically:
  • the target 3D light spot array uses the corresponding fractional order to perform forward fractional Fourier transform to obtain the light field distribution of the focal plane at any distance;
  • the movement of the workpiece is driven by the motion platform, and the fractional Fourier holographic femtosecond laser three-dimensional parallel processing is performed on any special-shaped surface profile or transparent material.
  • the system and method described in this disclosure can control the focused position of the beam without changing the focal length of the lens, and use a programmable liquid crystal spatial light modulator to modulate the femtosecond laser beam to obtain a three-dimensionally distributed focused spot array, which can achieve transparent 3D parallel machining of material interiors and non-transparent material surfaces.
  • the system and method described in the present disclosure determine the location and depth information of the microstructure according to the surface topography of the workpiece and the distribution, size, shape and other characteristics of the microstructure, and design the three-dimensional lattice distribution and target pattern. Accurate microstructures and precise positional relationships can be obtained without a precision machining platform, reducing machining errors.
  • the optical interferometric measurement system is used to describe the surface profile features of the processed object before laser processing is performed. Combined with the surface topography of the workpiece and the automatic design of the best target design, it can monitor the transparency in real time. Or the processing status of opaque materials and feedback processing result information, improve laser energy utilization and laser microstructure processing efficiency, and will become an important part of intelligent manufacturing technology in the future.
  • the fractional Fourier transform three-dimensional hologram calculation method proposed in this disclosure is based on the fractional Fourier transform. Due to the introduction of fractional variables, the application of holographic processing technology in laser processing is more flexible and variable. , which can realize the distribution of a single three-dimensional hologram corresponding to a multi-dimensional laser spot array. On the premise of ensuring the calculation speed of the hologram, only one parameter of fractional order can be adjusted to achieve the purpose of multi-dimensional focusing processing at the target distance.
  • control terminal cooperates to control the loading of the 3D hologram and the movement of the working platform, the interference image and the processing result information are collected by the camera, and the analysis feedback and the next calculation are carried out through image processing. Orderly operation, high degree of automation, saving time and labor costs.
  • FIG. 1 is a schematic diagram of the fractional Fourier holography femtosecond laser three-dimensional parallel processing system provided in Embodiment 1 of the present disclosure.
  • FIG. 2 is an optical path diagram of a three-dimensional parallel monitoring system for fractional Fourier holography femtosecond laser provided in Embodiment 1 of the present disclosure.
  • FIG. 3 is an optical path diagram of real-time monitoring of the processing process and optical interferometry provided by Embodiment 1 of the present disclosure.
  • FIG. 4 is a flowchart of a method for calculating a fractional Fourier transform three-dimensional hologram according to Embodiment 1 of the present disclosure.
  • Fig. 5 is a flowchart of the implementation of the fractional Fourier holography femtosecond laser three-dimensional parallel processing provided in Embodiment 1 of the present disclosure.
  • Embodiment 1 of the present disclosure proposes a fractional Fourier holography femtosecond laser three-dimensional parallel processing system, as shown in FIG. 1 and FIG. 2 .
  • the system described in this embodiment can use a programmable liquid crystal spatial light modulator (LOC-SLM) to modulate the femtosecond laser beam without changing the focal length of the lens to control the focused position of the beam to obtain a three-dimensionally distributed focused spot array,
  • LOC-SLM programmable liquid crystal spatial light modulator
  • the three-dimensional parallel processing technology of the interior of transparent materials and the surface of non-transparent materials can be realized, and it is a precise and efficient multi-dimensional laser processing method.
  • the realization of femtosecond laser three-dimensional parallel processing technology is based on fractional Fourier transform. Due to the introduction of fractional order variables, the application of holographic processing technology in laser processing is more flexible and variable, which can realize the adjustment of a single hologram.
  • the single-layer processing position can also realize a single three-dimensional hologram to adjust the distribution of the multi-dimensional laser spot array. processing purpose.
  • the core of the fractional Fourier holography femtosecond laser three-dimensional parallel processing technology is to add the hologram corresponding to the multi-dimensional spot focus array to the spatial light modulator, which can split the femtosecond laser irradiated on the liquid crystal window of the spatial light modulator.
  • the calculation of the three-dimensional fractional Fourier hologram is the key to realize multi-dimensional spot focusing. Therefore, on the basis of the fractional Fourier transform in the single-lens system, which can be imaged at any distance, a three-dimensional target image reconstruction technology has been developed.
  • the target pattern serves as the reconstructed 3D distributed focused spot.
  • the processing system includes a spatial light modulator 5, a Fourier lens 6, a first lens 7, a first beam splitter 9 and a first focusing objective lens 8.
  • a spatial light modulator 5 After the fractional Fourier hologram 5-2 is calculated , load it on the spatial light modulator 5, and fully modulate the femtosecond laser beam 5-1 irradiated on the liquid crystal window of the spatial light modulator into several sub-beams;
  • Each of the sub-beams is focused on the reconstruction focusing plane of any distance through the Fourier lens 6, which are respectively the first reconstructed focusing plane 6-1, the second reconstructed focusing plane 6-2 and the third reconstructed focusing plane 6-3, Simultaneously obtain corresponding target images at different positions;
  • the light spot array is focused at three different depths of the specific focusing processing position, which are the first focusing processing position 8-1 and the second focusing processing position.
  • the position 8-2 and the first focus processing position 8-3 realize the three-dimensional parallel processing of the femtosecond laser.
  • the entire optical processing system is built on a precise optical platform to ensure the alignment and spacing of optical elements in the entire optical path.
  • All optical lenses and instruments are installed and fixed by using precisely matched posts and optical adjustment frames. Precisely control the height and rotation angle of each component in the optical path system, precisely adjust the transmission direction of the beam, and reduce the energy loss during transmission.
  • the output beam quality of the laser source determines the final processing quality.
  • the parallel processing system described in this embodiment uses the near-infrared femtosecond laser 1 as the laser source to flexibly control the output parameters of the laser; it has an ultra-short pulse width. and ultra-high peak power femtosecond laser beam for parallel processing, not only can process high-quality material surface microtexture, but also improve the processing efficiency of microstructure array; parallel processing can also improve the utilization of laser energy while avoiding The problem of over-ablation during processing.
  • a beam adjustment system which consists of a half-wave plate 2 and a polarization cube 3, which can adjust the laser processing energy by changing the polarization direction; a beam expander 4 is placed in the optical path to amplify the diameter of the beam, making it slightly larger than the space beam Modulator's liquid crystal window size for better beam modulation.
  • the spatial light modulator is the core element to realize beam modulation.
  • the spatial light modulator is used to load the hologram generated by calculation, and control the deflection direction of the liquid crystal molecules through electrical signals, so as to achieve the modulation of the optical path difference of the beam. Purpose.
  • the 4f reconstruction system provided in this embodiment is a common optical information processing system.
  • the Fourier lens 6 in the front provides a space for the modulated light beam to reconstruct the target pattern, and a multifocal array can be obtained at any distance;
  • the first lens in the back 7 not only realizes the beam reduction effect, but also forms another 4f processing system with the focusing objective lens 8, which is reflected by the first dichroic beam splitter 9, and finally focuses the beam at a specific processing position.
  • Embodiment 2 of the present disclosure provides a fractional Fourier holographic femtosecond laser three-dimensional parallel processing monitoring system, as shown in FIG. 3 , FIG. 4 , and FIG. 5 , including the parallel processing system described in Embodiment 1 of the present disclosure and an LED white a light source 11, a first collimating mirror 12, a second beam splitter 13, an infrared filter 10, a second lens 14, and a first CCD camera 15;
  • the light beam emitted by the LED white light source 11 sequentially passes through the first collimating mirror 12, the second beam splitter 13, the infrared filter 10 and the first focusing objective lens 8 to reach the surface of the workpiece;
  • the reflected light reaches the first CCD camera 15 through the first focusing objective lens 8 , the infrared filter 10 , the second beam splitter 13 and the second lens 14 in sequence, and real-time monitoring of workpiece processing is performed according to the image received by the first CCD camera 15 , obtain the real-time monitoring image 15-1.
  • the laser processing real-time monitoring system observes the processing process and feeds back the processing results through the real-time monitoring system during the processing.
  • the measurement position workpiece 23 on the measurement position platform 24 is moved to the processing position platform 26 by using the motion level.
  • the machining position platform is provided with a moving machining position workpiece 25, the measuring position workpiece 23 and the machining position workpiece 25 are different positions of the same workpiece, and the machining position platform 26 and the measuring position platform 24 are different positions of the same platform.
  • the monitoring system further includes an optical interferometric measurement system
  • the optical interferometric measurement system includes a coherent light source 16 , a second collimating mirror 17 , a third beam splitter 20 , a reflecting mirror 21 , a third lens 19 , and a third lens 19 .
  • the second focusing objective lens 22 and the second CCD camera 18, the coherent light emitted by the coherent light source is divided into measurement light and reference light through the second collimating mirror and the third beam splitting mirror in turn;
  • the measurement light is irradiated to the workpiece surface through the second focusing objective lens, and the interference light after the interference of the reflected light and the reference light reaches the second CCD camera through the third lens. According to the phase difference between the measurement light wave and the reference light wave, the workpiece surface profile and depth information are obtained.
  • optical interferometric measurement system is used to describe the surface profile features of the processed object before laser processing is performed. Combined with the surface topography of the workpiece and the automatic design of the best target design, it will become an important part of intelligent manufacturing technology in the future;
  • the surface measurement is carried out before the laser processing.
  • the surface measurement system mainly includes a coherent light source 16.
  • the coherent light is divided into measurement light and reference light by the collimating mirror 17 and the third beam splitter 20, and the measurement light is irradiated by the focusing objective lens 22 to the
  • the workpiece surface 23 interferes with the reference light obtained by the reflection of the mirror 21 after reflection, and receives the interference image on the CCD camera 18 by the lens 19; analyzes the coherent superposition of the measurement light wave and the reference light wave through image processing technology to determine the phase difference of the two beams of light , thereby obtaining the depth information of the surface and the surface profile 18-1.
  • the control terminal 28 is connected to the controller of the motion platform, the spatial light modulator and the laser, and the controllers are respectively the platform motion controller 27, the SLM controller 29 and the laser controller 30, and the control terminal controls the motion through the respective controllers.
  • the operation of the platform, the loading of the spatial light modulator hologram, and the start and stop of the laser processing system coordinately control the entire 3D parallel processing system, and at the same time cooperate with efficient information collection to achieve automatic feedback and information processing of processing results.
  • Embodiment 3 of the present disclosure provides a method for three-dimensional parallel processing of fractional Fourier holography femtosecond lasers, using the monitoring system described in Embodiment 2, including the following steps:
  • S1 Optical interferometry measures the surface profile of the workpiece, and transmits the interference image captured by the camera to the control center to obtain the three-dimensional surface topography after image processing;
  • control center converts the surface contour of the workpiece into lattice information
  • S3 Design the target pattern and the corresponding coordinate file according to different depth information; the positions with the same depth information in the 3D distributed focus array correspond to the same fractional order, and the 3D fractional Fourier hologram is calculated by the iterative fractional Fourier transform algorithm ;
  • the space spot array focuses the femtosecond laser at the specific processing position through the focusing objective lens, and realizes precise three-dimensional parallel micromachining without platform movement;
  • the iterative fractional Fourier transform algorithm calculates the three-dimensional fractional Fourier hologram, which specifically includes the following steps:
  • the location and depth information of the microstructure are determined, and the three-dimensional lattice distribution and target pattern are designed.
  • the computer converts the three-dimensional distributed lattice target pattern into the point coordinate file of the corresponding position, the computer reads the coordinate file, and uses the Iterative Fractional Fourier Algorithm (IFRTA) improved based on the Gerchberg–Saxton algorithm to perform three-dimensional analysis. Design and iterative computation of holograms.
  • IFRTA Iterative Fractional Fourier Algorithm
  • f(x,y) and H(u,v) are the input and output light field distributions in the calculation process, respectively, f is the focal length of the lens; p is the size of the fractional order, which determines the distance z of the reconstructed image.
  • embodiments of the present disclosure may be provided as a method, system, or computer program product. Accordingly, the present disclosure may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable storage media having computer-usable program code embodied therein, including but not limited to disk storage, optical storage, and the like.
  • These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions
  • the apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.
  • the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM), or a random access memory (Random Access Memory, RAM) or the like.

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Abstract

一种分数傅里叶全息飞秒激光三维并行加工***，包括空间光调制器（5）、傅里叶透镜（6）、第一透镜（7）、第一分光镜（9）和第一聚焦物镜（8），空间光调制器被配置为接收飞秒激光光束和分数傅里叶全息图（5-2），发出经过调制后的多路光束到多个聚焦平面；穿过聚焦平面的光束依次通过第一透镜、第一分光镜和第一聚焦物镜后，光斑阵列聚焦在具体加工位置的多个不同深度。还涉及一种分数傅里叶全息飞秒激光三维并行加工监测***和加工方法。该加工***、加工监测***和加工方法，解决了复杂形状微结构加工的困难，有效提高了三维分布微结构的加工质量和加工效率，大大提高了三维分布的结构间位置精度。

Description

分数傅里叶全息飞秒激光三维并行加工、监测***及方法 技术领域
本公开涉及超快激光精密加工技术与光学全息加工技术领域，特别涉及一种分数傅里叶全息飞秒激光三维并行加工、监测***及方法。
背景技术
本部分的陈述仅仅是提供了与本公开相关的背景技术，并不必然构成现有技术。
随着材料科学的高速发展和应用，现代尖端制造技术已不再局限于精度和尺度上的微细化，在加工维度和效率上寻求新的突破已成为重要任务。激光加工作为一种非接触式加工技术，加工方法灵活，应用广泛。在加工方式上，不仅可以通过去除材料基体加工目标结构，如激光刻蚀、激光打孔、激光清洗等，同时还可以应用于增材制造，实现复杂结构的制备，如激光3D打印、激光熔覆等；在加工材料上，不仅可以加工传统手段难以处理的不透明金属或陶瓷材料，还可以加工透明材料内部结构。尤其是超快激光的出现，使得激光加工技术的应用到了更加尖端的航空航天、生物医药、半导体芯片制造领域。激光加工技术的加工精度可以从毫米到纳米尺度，应用于芯片加工制造的光刻技术已实现几个纳米结构的加工，但激光技术的高精度和传统加工维度也限制了加工效率的进一步提升。未来突破激光多维加工和效率的限制，将成为激光微纳制造技术的发展和工业化应用的巨大推动力。
全息飞秒激光加工因其灵活多变的光调制特性，为三维尺度和高加工效率 提供了新颖的解决方案。随着全息加工技术的不断发展，出现了一些新颖的光场调制计算方法，多用于双光子聚合技术，通过多层二维图案扫描配合移动平台完成的三维结构的制备。目前，三维激光光斑广泛应用于光镊、双光子聚合、生物医疗以及表面微织构制备等领域。
本公开发明人发现，现有的全息飞秒激光加工技术受到多维尺度限制，无法实现复杂形状微结构加工；而且现有的加工方式也无法简单快捷的实现三维光场调制，加工效率较低。
发明内容
为了解决现有技术的不足，本公开提供了一种分数傅里叶全息飞秒激光三维并行加工、监测***及方法，克服了多维尺度加工和低效率的问题，解决了复杂形状微结构加工的困难，有效提高了三维分布微结构的加工质量和加工效率，将加工效率提高到了一个数量级以上，显著缩短了加工时间，大大提高了三维分布的结构间位置精度。
为了实现上述目的，本公开采用如下技术方案：
本公开第一方面提供了一种分数傅里叶全息飞秒激光三维并行加工***。
一种分数傅里叶全息飞秒激光三维并行加工***，包括空间光调制器、傅里叶透镜、第一透镜、第一分光镜和第一聚焦物镜；
所述空间光调制器被配置为接收飞秒激光光束和分数傅里叶全息图，发出经过调制后的多路光束到多个聚焦平面；
穿过聚焦平面的光束依次通过第一透镜、第一分光镜和第一聚焦物镜后，光斑阵列聚焦在具体加工位置的多个不同深度。
作为可能的一些实现方式，还包括激光器，所述激光器为近红外飞秒激光 器。
作为进一步的限定，还包括半波片、偏振立方体和扩束器，激光器发出的激光依次通过半波片、偏振立方体和扩束器后到达空间光调制器。
本公开第二方面提供了一种分数傅里叶全息飞秒激光三维并行加工监测***。
一种分数傅里叶全息飞秒激光三维并行加工监测***，包括本公开第一方面所述的并行加工***以及LED白光源、第一准直镜、第二分光镜、红外滤光片、第二透镜、第一CCD相机；
LED白光源发出的光束依次经第一准直镜、第二分光镜、红外滤光片和第一聚焦物镜后到达加工工件表面；
反射光依次经第一聚焦物镜、红外滤光片、第二分光镜和第二透镜后到达第一CCD相机，根据第一CCD相机接收到的图像进行工件加工的实时监测。
作为可能的一些实现方式，还包括光学干涉测量***；
所述光学干涉测量***包括相干光源、第二准直镜、第三分光镜、反射镜、第三透镜、第二聚焦物镜和第二CCD相机，相干光源发出的相干光依次经第二准直镜和第三分光镜后分成测量光和参考光；
测量光经第二聚焦物镜照射到工件表面，反射光与参考光干涉后的干涉光经第三透镜到达第二CCD相机，根据测量光波与参考光波的相位差，得到工件表面轮廓和深度信息。
作为进一步的限定，还包括运动平台和控制终端，工件设置在运动平台上，所述运动平台、加工***和监测***均设置在光学平台上，所述控制终端分别与空间光调制器的控制器、激光器的控制器以及运动平台通信连接。
本公开第三方面提供了一种分数傅里叶全息飞秒激光三维并行加工方法。
一种分数傅里叶全息飞秒激光三维并行加工方法，利用本公开第二方面所述的分数傅里叶全息飞秒激光三维并行加工监测***，包括以下步骤：
采用光学干涉法测量工件表面轮廓，将采集到的干涉图像经图像处理获得工件表面的三维形貌；
根据工件表面的三维形貌和目标微结构的特征，设计三维点阵分布和目标图案，通过迭代分数阶傅里叶变换方法计算三维分数阶傅里叶全息图；
将得到的全息图加载到空间光调制器，进行三维目标焦点图像重建，飞秒激光束被调制为多光束，在空间中不同的聚焦平面完成三维光斑聚焦；
空间光斑阵列经聚焦物镜将飞秒激光聚焦在具体加工位置，进行工件表面的三维并行微加工。
作为可能的一些实现方式，根据工件的表面形貌以及微结构的分布、大小和形状特征，确定微结构的所在位置以及深度信息，设计三维点阵分布和目标图案；
将三维点阵分布和目标图案转化为对应位置的点坐标文件，读取坐标文件，利用基于Gerchberg-Saxton算法改进的迭代分数阶傅里叶算法进行三维全息图的设计与迭代计算。
作为可能的一些实现方式，迭代分数阶傅里叶变换方法，具体为：
设定飞秒激光光场振幅和初始相位，得到入射光场分布；
根据目标三维光斑阵列不同的设计距离，使用对应的分数阶进行正向的分数阶傅里叶变换得到任意距离聚焦平面光场分布；
按照设计光场的振幅对输出光场的振幅进行约束，得到约束振幅；
保持每个聚焦平面的相位不变，结合振幅表示约束的光场分布，以此进行逆向分数阶傅里叶变换，计算得到输入平面光场分布的振幅和相位分布；
一次迭代中遍历所有分数阶，获得目标光场分布；
获得全部的光场分布后，根据实部和虚部信息计算全息图的相位值；
若上述全息图未达到目标重建要求或未满足设定条件，继续以入射光场强度代替计算得到的振幅值，保留相位不变，进行下一次迭代运算；
迭代计算直至得到所需的目标三维焦点阵列，运算达到设定条件或设定次数停止运算，取其相位值作为对应的计算机全息图的相位分布。
作为可能的一些实现方式，通过运动平台带动工件的移动，对任意异型表面轮廓或透明材料进行分数阶傅里叶全息飞秒激光三维并行加工。
与现有技术相比，本公开的有益效果是：
1、本公开所述的***及方法，无需改变透镜焦距就可以控制光束聚焦的位置，利用可编程的液晶空间光调制器调制飞秒激光束，获得三维任意分布的聚焦光斑阵列，可实现透明材料内部和非透明材料表面的三维并行加工。
2、本公开所述的***及方法，根据工件的表面形貌以及微结构的分布、大小、形状等特征，确定微结构的所在位置以及深度信息，设计三维点阵分布和目标图案，可以在没有精密加工平台的条件下获得精密的微结构，以及精确的位置关系，减少加工误差。
3、本公开所述的***及方法，光学干涉测量***在实施激光加工前，用于描述加工对象的表面轮廓特征，结合工件的表面形貌和自动设计最佳的目标设计，可以实时监测透明或不透明材料的加工状态和反馈加工结果信息，提高激光能量利用率和激光微结构加工效率，未来将成为智能制造技术的重要组成部 分。
4、本公开提出的分数阶傅里叶变换三维全息图计算方法，以分数阶傅里叶变换为基础的，由于分数阶变量的引入，使得全息加工技术在激光加工中的应用更加灵活可变，可实现单个三维全息图对应多维激光光斑阵列的分布，在保证全息图计算速度的前提下，仅需调节分数阶一个参数便可完成在目标距离多维聚焦加工的目的。
5、本公开所述的***及方法，控制终端协同控制三维全息图加载和工作平台的移动，由相机采集干涉图像和加工结果信息，经图像处理进行分析反馈和下一步计算，各装置和子***有序运行，自动化程度高，节省时间和人力成本。
本公开附加方面的优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本公开的实践了解到。
附图说明
构成本公开的一部分的说明书附图用来提供对本公开的进一步理解，本公开的示意性实施例及其说明用于解释本公开，并不构成对本公开的不当限定。
图1为本公开实施例1提供的分数傅里叶全息飞秒激光三维并行加工***的原理图。
图2为本公开实施例1提供的分数傅里叶全息飞秒激光三维并行监测***光路图。
图3为本公开实施例1提供的加工过程实时监测和光干涉测量光路图。
图4为本公开实施例1提供的分数阶傅里叶变换三维全息图计算方法流程图。
图5为本公开实施例1提供的分数傅里叶全息飞秒激光三维并行加工实施 流程图。
图中，1、飞秒激光器；2、半波片；3、偏振立方体；4、扩束器；5、空间光调制器；5-1、激光束；5-2、加载全息图；6、傅里叶透镜；6-1、第一重建聚焦平面；6-2、第二重建聚焦平面；6-3、第三重建聚焦平面；7、第一透镜；8、第一聚焦物镜；8-1、第一聚焦加工位置；8-2、第二聚焦加工位置；8-3、第三聚焦加工位置；9、二色分光镜；10、红外滤光片；11、LED白光源；12、第一准直透镜；13、第二分光镜；14、第一成像透镜；15、第一CCD相机；15-1、实时监控图像；16、相干光源；17、第二准直透镜；18、第二CCD相机；18-1、干涉测量图像；19、第二成像透镜；20、第三分光镜；21、反射镜；22、第二聚焦物镜；23、测量位置工件；24、测量位置平台；25、加工位置工件；26、加工位平台；27、平台运动控制器；28、控制终端；29、SLM控制器；30、激光器控制器。
具体实施方式
下面结合附图与实施例对本公开作进一步说明。
应该指出，以下详细说明都是示例性的，旨在对本公开提供进一步的说明。除非另有指明，本文使用的所有技术和科学术语具有与本公开所属技术领域的普通技术人员通常理解的相同含义。
需要注意的是，这里所使用的术语仅是为了描述具体实施方式，而非意图限制根据本公开的示例性实施方式。如在这里所使用的，除非上下文另外明确指出，否则单数形式也意图包括复数形式，此外，还应当理解的是，当在本说明书中使用术语“包含”和/或“包括”时，其指明存在特征、步骤、操作、器件、组件和/或它们的组合。
在不冲突的情况下，本公开中的实施例及实施例中的特征可以相互组合。
实施例1：
正如背景技术所介绍的，现有激光加工技术存在加工维度和效率限制，成为激光微纳制造技术发展和工业化应用的阻碍。为了解决如上的技术问题，突破激光多维加工和效率的限制，本公开实施例1提出了一种分数傅里叶全息飞秒激光三维并行加工***，如图1和图2所示。
本实施例所述的***可以在不需要改变透镜焦距来控制光束聚焦的位置，利用可编程的液晶空间光调制器(LOC-SLM)调制飞秒激光束，获得三维任意分布的聚焦光斑阵列，可实现透明材料内部和非透明材料表面的三维并行加工技术，是一种精密且高效的多维激光加工方法。
飞秒激光三维并行加工技术的实现是以分数阶傅里叶变换为基础的，由于分数阶变量的引入，使得全息加工技术在激光加工中的应用更加灵活可变，既可以实现单个全息图调节单层加工位置，还可以实现单个三维全息图调节多维激光光斑阵列的分布，其最大的优势是在保证全息图计算速度的前提下，仅需调节分数阶一个参数便可完成在目标距离多维聚焦加工的目的。
分数傅里叶全息飞秒激光三维并行加工技术的核心是将对应多维光斑焦点阵列的全息图加到空间光调制器，可以对照射在空间光调制器液晶窗口的飞秒激光进行分束调制。三维分数阶傅里叶全息图的计算是实现多维光斑聚焦的关键，因此，单透镜***中分数阶傅里叶变换可以任意距离成像的基础上，开发了三维的目标图像重建技术，将多维的目标图案作为重建的三维分布聚焦光斑。
具体的，所述加工***包括空间光调制器5、傅里叶透镜6、第一透镜7、第一分光镜9和第一聚焦物镜8，分数傅里叶全息图5-2被计算完成后，将其加载到 空间光调制器5上，对照射在空间光调制器液晶窗口的飞秒激光束5-1充分调制分成若干分光束；
各条分光束经傅里叶透镜6分别聚焦在任意距离的重建聚焦平面上，分别为第一重建聚焦平面6-1、第二重建聚焦平面6-2和第三重建聚焦平面6-3，在不同位置上同时获得对应的目标图像；
最终通过第一透镜7和第一聚焦物镜8组成的另一个4f加工***，将光斑阵列聚焦在具体聚焦加工位置的三个不同深度，分别为第一聚焦加工位置8-1、第二聚焦加工位置8-2和第一聚焦加工位置8-3，实现了飞秒激光的三维并行加工。
本实施例中，整个光学加工***搭在精密的光学平台上搭建，保证整个光路中光学元件的准直和间距，利用精密配合的接杆和光学调整架安装固定全部的光学镜片和仪器，并精确控制各个元件在光路***中的高度和旋转角度，精密调整光束的传递方向，减小传输过程中的能量损失。
激光加工中，激光源的输出光束质量决定着最终的加工质量，本实施例所述的并行加工***采用近红外飞秒激光器1作为激光源，灵活的控制激光器的输出参数；具有超短脉宽和超高峰值功率的飞秒激光束用于并行加工，不仅可以加工高质量的材料表面微织构，还可以提高微结构阵列的加工效率；并行加工还可以在提高激光能量利用率的同时避免加工中过烧蚀的问题。
还包括有光束调整***，由半波片2和偏振立方体3组成，通过改变偏振方向实现对激光加工能量的调节；在光路中放置扩束器4以放大光束的直径，使其略大于空间光调制器的液晶窗口尺寸，以获得更好的光束调制效果。
所述空间光调制器是实现光束调制的核心元件，在全息技术光路中，空间光调制器用于加载计算生成的全息图，并通过电信号控制液晶分子的偏转方向， 达到调制光束光程差的目的。
本实施例提供的4f重建***是常见的光学信息处理***，前面的傅里叶透镜6为调制后的光束提供重建目标图案的空间，在任意距离上可以获得多焦点阵列；后面的第一透镜7不仅对光束实现缩束效果，同时与聚焦物镜将8组成另一个4f加工***，经二色的第一分光镜9反射，最终将光束聚焦在特定的加工位置。
实施例2：
本公开实施例2提供了一种分数傅里叶全息飞秒激光三维并行加工监测***，如图3、图4和图5所示，包括本公开实施例1所述的并行加工***以及LED白光源11、第一准直镜12、第二分光镜13、红外滤光片10、第二透镜14、第一CCD相机15；
LED白光源11发出的光束依次经第一准直镜12、第二分光镜13、红外滤光片10和第一聚焦物镜8后到达加工工件表面；
反射光依次经第一聚焦物镜8、红外滤光片10、第二分光镜13和第二透镜14后到达第一CCD相机15，根据第一CCD相机15接收到的图像进行工件加工的实时监测，获得实时监测图像15-1。
激光加工实时监测***在加工过程中通过实时监测***对加工过程进行观察和加工结果进行反馈，实施激光加工时，利用运动平将测量位置平台24上的测量位置工件23移动到加工位置平台26，加工位置平台上设有移动过来的加工位置工件25，测量位置工件23和加工位置工件25为同一个工件的不同位置，加工位置平台26和测量位置平台24为同一平台的不同位置。
本实施例中，所述监测***还包括光学干涉测量***，所述光学干涉测量***包括相干光源16、第二准直镜17、第三分光镜20、反射镜21、第三透镜19、 第二聚焦物镜22和第二CCD相机18，相干光源发出的相干光依次经第二准直镜和第三分光镜后分成测量光和参考光；
测量光经第二聚焦物镜照射到工件表面，反射光与参考光干涉后的干涉光经第三透镜到达第二CCD相机，根据测量光波与参考光波的相位差，得到工件表面轮廓和深度信息。
光学干涉测量***在实施激光加工前，用于描述加工对象的表面轮廓特征，结合工件的表面形貌和自动设计最佳的目标设计，未来将成为智能制造技术的重要组成部分；
在加工***中表面测量先于激光加工进行，表面测量***主要包括相干光源16，通过准直镜17和第三分光镜20将相干光分成测量光和参考光，测量光经聚焦物镜22照射到工件表面23，反射后与反射镜21反射获得的参考光干涉，并由透镜19在CCD相机18上接收干涉图像；通过图像处理技术分析测量光波和参考光波的相干叠加确定两束光的相位差，从而获得表面的深度信息和表面轮廓18-1。
所述控制终端28连接运动平台、空间光调制器以及激光器的控制器，所述控制器分别为平台运动控制器27、SLM控制器29和激光器控制器30，控制终端通过各个控制器分别控制运动平台的动作、空间光调制器全息图的加载以及激光加工***的启停等操作，协同控制整个三维并行加工***，同时配合高效的信息采集，实现加工结果的自动反馈和信息处理。
实施例3：
本公开实施例3提供了一种分数傅里叶全息飞秒激光三维并行加工方法，利用实施例2所述的监测***，包括以下步骤：
S1：光学干涉法测量工件表面轮廓，将相机采集干涉图像传输至控制中心经图像处理获得表面三维形貌；
S2：结合工件表面三维形貌和目标微结构的分布、大小、形状等特征，由控制中心将工件表面轮廓转化为点阵信息；
S3：根据不同的深度信息，设计目标图案和对应坐标文件；三维分布焦点阵列中深度信息相同的位置对应同一个分数阶，通过迭代分数阶傅里叶变换算法计算三维分数阶傅里叶全息图；
S4：将计算的全息图加载到空间光调制器，在光学加工***中实现三维目标焦点图像重建，飞秒激光束照射在液晶窗口被调制为多光束，并通过透镜在空间中不同的聚焦平面完成三维光斑聚焦；
S5：空间光斑阵列经聚焦物镜将飞秒激光聚焦在具体加工位置，在没有平台移动的状态实现精密的三维并行微加工；
S6：针对任意的异型表面轮廓或透明材料，配合运动平台实现灵活的分数阶傅里叶全息飞秒激光三维并行加工。
迭代分数阶傅里叶变换算法计算三维分数阶傅里叶全息图，具体包括如下步骤：
首先，根据工件的表面形貌以及微结构的分布、大小、形状等特征，确定微结构的所在位置以及深度信息，设计三维点阵分布和目标图案。
然后，计算机将三维分布点阵目标图案转化为对应位置的点坐标文件，计算机读取坐标文件，利用基于Gerchberg–Saxton算法改进的迭代分数阶傅里叶算法(Iterative Fractional Fourier Algorithm，IFRTA)进行三维全息图的设计与迭代计算。
单透镜***中光场传递的分数阶傅里叶变换的公式如下：
Figure PCTCN2021073318-appb-000001
其中，f(x,y)和H(u,v)分别为计算过程中输入和输出光场分布，f为透镜的焦距；p为分数阶的大小，决定了重建图像的距离z。
具体的分数阶傅里叶变换全息图迭代计算方法和步骤如下：
S3.1：设定的飞秒激光光场振幅为A in和初始相位φ initial得到入射光场分布的表达式为：
Figure PCTCN2021073318-appb-000002
S3.2：根据目标三维光斑阵列不同的设计距离z j，使用对应的分数阶p j进行正向的分数阶傅里叶变换得到任意距离聚焦平面光场分布为：
Figure PCTCN2021073318-appb-000003
S3.3：按照设计光场的振幅A target对输出光场的振幅A out进行约束，得到约束振幅
Figure PCTCN2021073318-appb-000004
S3.4：保持每个聚焦平面的相位不变，结合振幅
Figure PCTCN2021073318-appb-000005
表示约束的光场分布，以此进行逆向分数阶傅里叶变换，计算得到输入平面光场分布的振幅和相位分布：
Figure PCTCN2021073318-appb-000006
S3.5：一次迭代中遍历所有分数阶p，获得距离的目标光场分布F；
S3.6：获得全部的光场分布F后，根据实部Re(F)和虚部Im(F)信息计算全息图的相位值；
Figure PCTCN2021073318-appb-000007
S3.7：若上述全息图未达到目标重建要求或未满足设定条件，继续以入射光场强度代替计算得到的振幅值，保留相位不变，进行下一次迭代运算S3.2-S3.6；
S3.8：迭代计算直至得到所需的目标三维焦点阵列，运算达到设定条件或设定次数k停止运算，取其相位值φ (k)即是所对应的计算机全息图对的相位分布。
本领域内的技术人员应明白，本公开的实施例可提供为方法、***、或计算机程序产品。因此，本公开可采用硬件实施例、软件实施例、或结合软件和硬件方面的实施例的形式。而且，本公开可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器和光学存储器等)上实施的计算机程序产品的形式。
本公开是参照根据本公开实施例的方法、设备(***)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器，使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。
这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理设备以特定方式工作的计算机可读存储器中，使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品，该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。
这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上，使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。
本领域普通技术人员可以理解实现上述实施例方法中的全部或部分流程，是可以通过计算机程序来指令相关的硬件来完成，所述的程序可存储于一计算机可读取存储介质中，该程序在执行时，可包括如上述各方法的实施例的流程。其中，所述的存储介质可为磁碟、光盘、只读存储记忆体(Read-Only Memory，ROM)或随机存储记忆体(Random AccessMemory，RAM)等。
以上所述仅为本公开的优选实施例而已，并不用于限制本公开，对于本领域的技术人员来说，本公开可以有各种更改和变化。凡在本公开的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本公开的保护范围之内。

Claims (10)

  1. 一种分数傅里叶全息飞秒激光三维并行加工***，其特征在于，包括空间光调制器、傅里叶透镜、第一透镜、第一分光镜和第一聚焦物镜；
    所述空间光调制器被配置为接收飞秒激光光束和分数傅里叶全息图，发出经过调制后的多路光束到多个聚焦平面；
    穿过聚焦平面的光束依次通过第一透镜、第一分光镜和第一聚焦物镜后，光斑阵列聚焦在具体加工位置的多个不同深度。
  2. 如权利要求1所述的分数傅里叶全息飞秒激光三维并行加工***，其特征在于，还包括激光器，所述激光器为近红外飞秒激光器。
  3. 如权利要求2所述的分数傅里叶全息飞秒激光三维并行加工***，其特征在于，还包括半波片、偏振立方体和扩束器，激光器发出的激光依次通过半波片、偏振立方体和扩束器后到达空间光调制器。
  4. 一种分数傅里叶全息飞秒激光三维并行加工监测***，其特征在于，包括权利要求1-3任一项所述的并行加工***以及LED白光源、第一准直镜、第二分光镜、红外滤光片、第二透镜、第一CCD相机；
    LED白光源发出的光束依次经第一准直镜、第二分光镜、红外滤光片和第一聚焦物镜后到达加工工件表面；
    反射光依次经第一聚焦物镜、红外滤光片、第二分光镜和第二透镜后到达第一CCD相机，根据第一CCD相机接收到的图像进行工件加工的实时监测。
  5. 如权利要求4所述的分数傅里叶全息飞秒激光三维并行加工监测***，其特征在于，还包括光学干涉测量***；
    所述光学干涉测量***包括相干光源、第二准直镜、第三分光镜、反射镜、第三透镜、第二聚焦物镜和第二CCD相机，相干光源发出的相干光依次经第二 准直镜和第三分光镜后分成测量光和参考光；
    测量光经第二聚焦物镜照射到工件表面，反射光与参考光干涉后的干涉光经第三透镜到达第二CCD相机，根据测量光波与参考光波的相位差，得到工件表面轮廓和深度信息。
  6. 如权利要求5所述的分数傅里叶全息飞秒激光三维并行加工监测***，其特征在于，还包括运动平台和控制终端，工件设置在运动平台上，所述运动平台、加工***和监测***均设置在光学平台上，所述控制终端分别与空间光调制器的控制器、激光器的控制器以及运动平台通信连接。
  7. 一种分数傅里叶全息飞秒激光三维并行加工方法，其特征在于，利用权利要求4-6任一项所述的分数傅里叶全息飞秒激光三维并行加工监测***，包括以下步骤：
    采用光学干涉法测量工件表面轮廓，将采集到的干涉图像经图像处理获得工件表面的三维形貌；
    根据工件表面的三维形貌和目标微结构的特征，设计三维点阵分布和目标图案，通过迭代分数阶傅里叶变换方法计算三维分数阶傅里叶全息图；
    将得到的全息图加载到空间光调制器，进行三维目标焦点图像重建，飞秒激光束被调制为多光束，在空间中不同的聚焦平面完成三维光斑聚焦；
    空间光斑阵列经聚焦物镜将飞秒激光聚焦在具体加工位置，进行工件表面的三维并行微加工。
  8. 如权利要求7所述的分数傅里叶全息飞秒激光三维并行加工方法，其特征在于，根据工件的表面形貌以及微结构的分布、大小和形状特征，确定微结构的所在位置以及深度信息，设计三维点阵分布和目标图案；
    将三维点阵分布和目标图案转化为对应位置的点坐标文件，读取坐标文件，利用基于Gerchberg-Saxton算法改进的迭代分数阶傅里叶算法进行三维全息图的设计与迭代计算。
  9. 如权利要求7所述的分数傅里叶全息飞秒激光三维并行加工方法，其特征在于，迭代分数阶傅里叶变换方法，具体为：
    设定飞秒激光光场振幅和初始相位，得到入射光场分布；
    根据目标三维光斑阵列不同的设计距离，使用对应的分数阶进行正向的分数阶傅里叶变换得到任意距离聚焦平面光场分布；
    按照设计光场的振幅对输出光场的振幅进行约束，得到约束振幅；
    保持每个聚焦平面的相位不变，结合振幅表示约束的光场分布，以此进行逆向分数阶傅里叶变换，计算得到输入平面光场分布的振幅和相位分布；
    一次迭代中遍历所有分数阶，获得目标光场分布；
    获得全部的光场分布后，根据实部和虚部信息计算全息图的相位值；
    若上述全息图未达到目标重建要求或未满足设定条件，继续以入射光场强度代替计算得到的振幅值，保留相位不变，进行下一次迭代运算；
    迭代计算直至得到所需的目标三维焦点阵列，运算达到设定条件或设定次数停止运算，取其相位值作为对应的计算机全息图的相位分布。
  10. 如权利要求7所述的分数傅里叶全息飞秒激光三维并行加工方法，其特征在于，通过运动平台带动工件的移动，对任意异型表面轮廓或透明材料进行分数阶傅里叶全息飞秒激光三维并行加工。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117289563A (zh) * 2023-11-27 2023-12-26 浙江大学杭州国际科创中心 一种振幅型计算全息图实现装置及方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113218926B (zh) * 2021-05-17 2023-06-20 北京京东方技术开发有限公司 一种光调制组件、荧光显微镜及芯片检测***及方法
CN113655652B (zh) * 2021-07-28 2024-05-07 深圳市麓邦技术有限公司 匀光元件的制备方法及***
CN113899320B (zh) * 2021-09-30 2023-10-03 中国科学院光电技术研究所 一种基于空间结构光场的高精度微纳三维形貌测量方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20050030006A (ko) * 2003-09-24 2005-03-29 한국기계연구원 펨토초 레이저를 사용하는 정밀 가공장치 및 가공방법
US20110108525A1 (en) * 2009-11-11 2011-05-12 Industrial Technology Research Institute Method and system for manufacturing microstructure in photosensitive glass substrate
CN102749793A (zh) * 2012-07-24 2012-10-24 东南大学 一种全息投影方法
CN103071930A (zh) * 2013-01-09 2013-05-01 南开大学 一种飞秒激光直写制备微孔阵列的***与方法
CN208223415U (zh) * 2018-02-09 2018-12-11 苏州大学 一种非接触式三维面形轮廓仪
CN110471135A (zh) * 2019-08-21 2019-11-19 吉林大学 制造曲面上微透镜阵列的方法以及包括由所述方法制成的曲面上微透镜阵列的光学装置
CN110510887A (zh) * 2019-08-21 2019-11-29 吉林大学 多焦点光学曲面的制造方法和光学装置
CN110877161A (zh) * 2019-11-20 2020-03-13 清华大学 一种基于空间整形飞秒激光分层扫描的异形孔加工***

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH061167B2 (ja) * 1988-05-17 1994-01-05 日本鋼管株式会社 ３次元曲面形状の測定方法及び装置
US6687418B1 (en) * 1999-02-25 2004-02-03 Lester Frank Ludwig Correction of image misfocus via fractional fourier transform
JP4716663B2 (ja) * 2004-03-19 2011-07-06 株式会社リコー レーザ加工装置、レーザ加工方法、及び該加工装置又は加工方法により作製された構造体

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20050030006A (ko) * 2003-09-24 2005-03-29 한국기계연구원 펨토초 레이저를 사용하는 정밀 가공장치 및 가공방법
US20110108525A1 (en) * 2009-11-11 2011-05-12 Industrial Technology Research Institute Method and system for manufacturing microstructure in photosensitive glass substrate
CN102749793A (zh) * 2012-07-24 2012-10-24 东南大学 一种全息投影方法
CN103071930A (zh) * 2013-01-09 2013-05-01 南开大学 一种飞秒激光直写制备微孔阵列的***与方法
CN208223415U (zh) * 2018-02-09 2018-12-11 苏州大学 一种非接触式三维面形轮廓仪
CN110471135A (zh) * 2019-08-21 2019-11-19 吉林大学 制造曲面上微透镜阵列的方法以及包括由所述方法制成的曲面上微透镜阵列的光学装置
CN110510887A (zh) * 2019-08-21 2019-11-29 吉林大学 多焦点光学曲面的制造方法和光学装置
CN110877161A (zh) * 2019-11-20 2020-03-13 清华大学 一种基于空间整形飞秒激光分层扫描的异形孔加工***

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117289563A (zh) * 2023-11-27 2023-12-26 浙江大学杭州国际科创中心 一种振幅型计算全息图实现装置及方法
CN117289563B (zh) * 2023-11-27 2024-04-19 浙江大学杭州国际科创中心 一种振幅型计算全息图实现装置及方法

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