基于高功率光纤激光器的光束整形镜研究
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摘要
激光淬火处理技术广泛应用于工业加工领域,但高斯光束的能量分布模式无法获得均匀的淬硬层深而阻碍了该技术的发展。光束整形器能通过改善光束的质量提高激光淬火质量,因而成为研究的热点,但很少被直接应用于激光淬火的工程实验之中。
结合实验室的设备条件,本文主要设计并加工了用于高功率光纤器淬火系统的光束整形器,将激光束能量分布由近似高斯分布转变成近似平顶分布,从而提高了激光淬火的质量。具体研究内容包括:(1)以几何光学和能量守恒定律等为依据,选用偶次非球面透镜作为整形元件,并确定了光束整形系统的初始数据(如镜片厚度、镜片间距、镜片直径等);(2)运用ZEMAX光学设计软件对光束整形系统进行了模拟分析,再根据相应的评价函数对系统进行优化,使整形后的光束能量分布尽量均匀,找出最优的方案。(3)将加工好的整形系统用于激光淬火实验,验证整形镜的整形效果。
实验结果表明:在系统工作面上的光斑除中心黑斑边缘有一亮环外,其余部分的能量密度较为均匀;在不考虑中心黑斑的情况下,光斑在工作面前后随工作距离的变化趋势与理论模拟一致。整形后激光束的工作距离较理论模拟值减小了90mm,而整形后的光斑在材料表面作用后得到的直径较理论值增加了1mm。最后,通过光纤激光淬火实验验证了整形镜的整形效果,基本达到设计的要求,获得的淬硬层深基本相同。
Laser quenching is widely used in industrial processing areas. The lasers with energy distribution of gaussian are often used during quenching processes, which retards the further development of this technology for not obtainting uniform deepth hardened layer. The quality of laser quenching can be improved by using the shaped laser beam in therory. However, a few research results are used in laser quenching experiments for potential applications.
In this thesis, a laser beam shaper used in high-power fiber laser quenching system was designed and assembled based on our laboratory conditions. The main aim is to change the distribution of the fiber laser beam from gaussian to approximately flat-top. The main studies include: (1) the even aspheric lens was selected as the lens of beam shaping system based on the geometric optics and energy conservation law. In addition, the initial data (including the thickness of the lens, distance and diameter) were determined. (2) The ZEMAX optical design software was used to simulate the beam shaper. Then the system was optimized according to the merit function to make the energy density of the laser beam homogenize. (3) The assembled shaper was used in the fiber laser quenching experiments to verify the effect of shaping.
The results show that the energy distribution of the spot is basically uniform except for a bright ring near the center black spot. When the center black spot is not considered and the laser spot locates near the working distance, the change of the spot size with the working distance is consistent with that of the simulation results. In experiment, the working distance is reduced by a value of 90 mm in comparison with the theoretical value. But the real spot size has increased 1 mm than the theoretical value. Finally, the laser quenching experiments based on the designed shaper can obtaint hardened layer with uniform depth, which demonstrates that the designed shaper has met the design requirements for high-power fiber laser quenching system.
结合实验室的设备条件,本文主要设计并加工了用于高功率光纤器淬火系统的光束整形器,将激光束能量分布由近似高斯分布转变成近似平顶分布,从而提高了激光淬火的质量。具体研究内容包括:(1)以几何光学和能量守恒定律等为依据,选用偶次非球面透镜作为整形元件,并确定了光束整形系统的初始数据(如镜片厚度、镜片间距、镜片直径等);(2)运用ZEMAX光学设计软件对光束整形系统进行了模拟分析,再根据相应的评价函数对系统进行优化,使整形后的光束能量分布尽量均匀,找出最优的方案。(3)将加工好的整形系统用于激光淬火实验,验证整形镜的整形效果。
实验结果表明:在系统工作面上的光斑除中心黑斑边缘有一亮环外,其余部分的能量密度较为均匀;在不考虑中心黑斑的情况下,光斑在工作面前后随工作距离的变化趋势与理论模拟一致。整形后激光束的工作距离较理论模拟值减小了90mm,而整形后的光斑在材料表面作用后得到的直径较理论值增加了1mm。最后,通过光纤激光淬火实验验证了整形镜的整形效果,基本达到设计的要求,获得的淬硬层深基本相同。
Laser quenching is widely used in industrial processing areas. The lasers with energy distribution of gaussian are often used during quenching processes, which retards the further development of this technology for not obtainting uniform deepth hardened layer. The quality of laser quenching can be improved by using the shaped laser beam in therory. However, a few research results are used in laser quenching experiments for potential applications.
In this thesis, a laser beam shaper used in high-power fiber laser quenching system was designed and assembled based on our laboratory conditions. The main aim is to change the distribution of the fiber laser beam from gaussian to approximately flat-top. The main studies include: (1) the even aspheric lens was selected as the lens of beam shaping system based on the geometric optics and energy conservation law. In addition, the initial data (including the thickness of the lens, distance and diameter) were determined. (2) The ZEMAX optical design software was used to simulate the beam shaper. Then the system was optimized according to the merit function to make the energy density of the laser beam homogenize. (3) The assembled shaper was used in the fiber laser quenching experiments to verify the effect of shaping.
The results show that the energy distribution of the spot is basically uniform except for a bright ring near the center black spot. When the center black spot is not considered and the laser spot locates near the working distance, the change of the spot size with the working distance is consistent with that of the simulation results. In experiment, the working distance is reduced by a value of 90 mm in comparison with the theoretical value. But the real spot size has increased 1 mm than the theoretical value. Finally, the laser quenching experiments based on the designed shaper can obtaint hardened layer with uniform depth, which demonstrates that the designed shaper has met the design requirements for high-power fiber laser quenching system.
引文
[1]朱培元.绿色制造激光加工.现代零部件, 2009, 2: 62~64
[2]王又良.激光加工的最新应用领域.应用激光, 2005, 25(5): 329~332
[3]张艳,张静娟,司徒国海.高斯光束变换成方形均匀焦斑的衍射光学元件的研究.中国激光, 2004, 31(10): 1183~1187
[4]郑国兴,杜春雷,王长涛.部分相干激光匀束器的设计及应用.光电子?激光, 2004, 15(7): 802~805
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[6]陶向阳,周南润,吕百达.用HIO算法研究光束的空间整形.激光技术, 2002, 26(6): 463~465
[7] Mendlovic D, ozaktas HM. Fractional Fourier transforms and their optical implementation-part I. JOSA, 1993, A10(9): 1875~1881
[8] Lohmann AW. Image rotation Wigner rotation and the fractional Fourier transform. JOSA, 1993, A10(10): 2181~2186
[9] Ozaktas HM, Mendlovic D. Fractional Fourier optics. JOSA, 1995, A12(4):743~751
[10] Dorsh G, Lohmann A W. Fractional Fourier transform used for a lens-design problem. Appl Op, 1995, 34(20): 4111~4112
[11]李琦,王骐,高惠德.输入光束光斑半径变化对BOE整形环的影响.激光技术, 2002, 26(1): 35~38
[12] Michael R.Duparre, Barbara Luedge, Richard M. Investigation of computer generated Diffractive Beam shapers For the Task of Gauss-to-Ring Laser-beam Transformation. SPIE, 1996, 2689: 112~119
[13]杨李茗,虞淑环.任意点阵衍射图形的BOE优化设计.光子学报, 1998, 27(8): 739~741
[14]张艳,张静娟,司徒国海.二维光束整形的衍射光学元件设计.量子电子学报, 2003, 20(6): 651~655
[15]高峰,刘建莉,高福华等.利用边缘相位校正实现光束整形的高精度优化.光学学报, 2004, 24(8): 1137~1141
[16]董梅峰,宋新祥.激光束整形为矩形光束的DOE的设计及实验.激光杂志, 2004, 25(5): 23~24
[17]谭峭峰,魏晓峰,向勇等. YG算法设计分数傅里叶变换衍射光学光束整形器.光子学报, 2005, 34(11): 1724~1727
[18]邹杰宇,卢亚雄,黄子强等.基于改进GS算法的衍射光学光束整形元件的设计.红外与激光工程, 2006, 35(增刊): 48~52
[19]李建龙,吕百达.基于自适应遗传算法部分相干光整形位相板的优化设计.物理学报, 2008, 57(5): 3006~3010
[20]谢杰,范薇,李学春等.二元振幅型面板用于光束空间整形.光学学报, 2008, 28(10): 1959~1966
[21]王智超,马晓辉.激光光束准直技术.仪器仪表用户, 2009, 16(3): 1~2
[22]林清华,宋超,王鲁宾等.用于光刻的准分子激光束整形及其研究进展.量子电子学报, 2007, 24(4): 415~419
[23] T.Bizjak, T.Mitra, L.Aschke. Novel high throughput microoptical beam shapers reduce the complexity of macrooptics in hyper-NV illumination systems. SPIE, 2007, 6520: 1~11
[24] Kajava T, Hakola A, Elfstrom H, et a1. Flat-top profile of an excimer laser beam generated using beam splitter gratings. Opt. Commun, 2006, 268: 289~293
[25] Turunen J, Paakkonen P, Kuittinen M, et a1. Diffractive shaping of excimer laser beams. Journal of Modern Optic, 2000, 47(13): 2467~2475
[26] Kopp C, Ravel L, Meyrueis P. Efficient beamshaper homogenizer design combining diffractive optical elements, microlens array and random phase plate. App1 Opt, 1999, 1: 398~403
[27]叶一东,吕百达,蔡邦维.强激光的时间整形和空间整形.激光技术, 1996, 20(6): 324~328
[28] Patrick W.Rhodes, David L.Shealy. Refractive optical systems for irradiance redistribution of collimated radiation:their design and analysis. Appl Opt, 1980,19(20): 3552~3553
[29] HOFFNAG LE J A, JEFFERSON CM. Design and perfor mance of a refractive op tical system that converts a Gaussian to a flatt op beam. Appl Opt, 2000, 39(30): 5488~5499
[30] CHANG S P, KUO JM,LEE Y P, et al. Transfor mation of Gaussian to coherent uniform beams by inverse Gaussian trans mittive filters. Appl Opt, 1998, 37(4): 747~752
[31] DICKEY F M, HOLS WADE S C. Laser beam shap ing: theory and techniques. New York:Marcel, 2000: 163~213
[32] Jiang W. Application of a laser beam profile reshaper to enhance performance of holographic projection systems: [D]. Birmingham: University of Alabama, 1993.
[33]李殿军,梁思远,曹建建.非球面伽利略扩束系统实现激光束空间整形.激光技术, 2008, 32(4): 427~429
[34]曾晓东,安毓英.堆积式大功率激光二极管光束整形.第10届全国光电技术与系统学术光电子技术与信息会议沦文, 2003, 16(增刊): 25~29
[35]高全华,曾晓东,安毓英.大功率半导体激光器光束整形.光电子?激光, 2005, 16(6): 662~664
[36] N.Konforti, Eluarom, S-T.wu. Phase-only modulation with twisted nematie liquid crystal Spatial light modulation. optics Letters, 1988, 13(3): 251~254
[37]陈怀新,隋展,陈祯培等.采用液晶空间光调制器进行激光光束的空间整形.光学学报, 2001, 21(9): 1107~1111
[38]关秀丽.液晶光束控制的研究.长春大学学报, 2006, 16(6): 58~62
[39]王华明,叶玉堂,吴云峰.微小激光曝光区域温度分布均匀化整形方法.光电工程, 2006, 33(4): 55~58
[40]郑建溯,于清旭,关寿华.强激光的靶面均匀辐照和光束匀滑技术.中央民族大学学报, 2008, 17(1): 29~36
[41]刘增水,黄慧杰,路敦武等.无规位相板靶面均匀辐照光学系统研究.强激光与粒子束, 1998, 10(3): 441~444
[42]龚华平,吕志伟,林殿阳.激光束空间整形的研究现状.激光与光电子展, 2005,42(9): 2~5
[43] Xijia Gu, Waleed Mohammed, Li Qian etal. All-Fiber Laser Beam Shaping at 1.0μm Wavelength Region in a Single-mode Fiber. SPIE, 2008, 7099: 1~5
[44] David L.Shealy. Theory of Geometrical Methods for Design of Laser Beam Shaping Systems. SPIE, 2000, 4095: 1~15
[45] Philip H.Malyak. Two-mirror unobscured optical system for reshaping the irradiance distribution of a laser beam. Appl Opt, 1992, 31(22): 4377~4383
[46] J.H.McDermi, T.E.Horton. Reflective Optics for Obtaining Prescribed Irradiative Distributions from Collimated Sources. Appl Opt, 1974, 13 (6) : 1444~1450
[47]郁道银,淡恒英.工程光学. (第二版). (北京):机械工业出版社, 2006. 104~129
[48]李晓彤,岑兆丰.几何光学?相差?光学设计. (第二版). (杭州):浙江大学出版社, 2003. 231~252
[49]王学新,杨照金,武波等.用2种光学设计软件对像差特性进行的研究.应用光学, 2006, 27(2): 124 ~128
[50]吕宪魁.大孔径单色傅里叶变换透镜的设计: [硕士学位论文].重庆:重庆大学图书馆, 2005.
[2]王又良.激光加工的最新应用领域.应用激光, 2005, 25(5): 329~332
[3]张艳,张静娟,司徒国海.高斯光束变换成方形均匀焦斑的衍射光学元件的研究.中国激光, 2004, 31(10): 1183~1187
[4]郑国兴,杜春雷,王长涛.部分相干激光匀束器的设计及应用.光电子?激光, 2004, 15(7): 802~805
[5]李松,叶建新.用于激光雷达光束整形的二元光学元件的设计和研究.激光与光电子学进展, 2008, 43(2): 11~13
[6]陶向阳,周南润,吕百达.用HIO算法研究光束的空间整形.激光技术, 2002, 26(6): 463~465
[7] Mendlovic D, ozaktas HM. Fractional Fourier transforms and their optical implementation-part I. JOSA, 1993, A10(9): 1875~1881
[8] Lohmann AW. Image rotation Wigner rotation and the fractional Fourier transform. JOSA, 1993, A10(10): 2181~2186
[9] Ozaktas HM, Mendlovic D. Fractional Fourier optics. JOSA, 1995, A12(4):743~751
[10] Dorsh G, Lohmann A W. Fractional Fourier transform used for a lens-design problem. Appl Op, 1995, 34(20): 4111~4112
[11]李琦,王骐,高惠德.输入光束光斑半径变化对BOE整形环的影响.激光技术, 2002, 26(1): 35~38
[12] Michael R.Duparre, Barbara Luedge, Richard M. Investigation of computer generated Diffractive Beam shapers For the Task of Gauss-to-Ring Laser-beam Transformation. SPIE, 1996, 2689: 112~119
[13]杨李茗,虞淑环.任意点阵衍射图形的BOE优化设计.光子学报, 1998, 27(8): 739~741
[14]张艳,张静娟,司徒国海.二维光束整形的衍射光学元件设计.量子电子学报, 2003, 20(6): 651~655
[15]高峰,刘建莉,高福华等.利用边缘相位校正实现光束整形的高精度优化.光学学报, 2004, 24(8): 1137~1141
[16]董梅峰,宋新祥.激光束整形为矩形光束的DOE的设计及实验.激光杂志, 2004, 25(5): 23~24
[17]谭峭峰,魏晓峰,向勇等. YG算法设计分数傅里叶变换衍射光学光束整形器.光子学报, 2005, 34(11): 1724~1727
[18]邹杰宇,卢亚雄,黄子强等.基于改进GS算法的衍射光学光束整形元件的设计.红外与激光工程, 2006, 35(增刊): 48~52
[19]李建龙,吕百达.基于自适应遗传算法部分相干光整形位相板的优化设计.物理学报, 2008, 57(5): 3006~3010
[20]谢杰,范薇,李学春等.二元振幅型面板用于光束空间整形.光学学报, 2008, 28(10): 1959~1966
[21]王智超,马晓辉.激光光束准直技术.仪器仪表用户, 2009, 16(3): 1~2
[22]林清华,宋超,王鲁宾等.用于光刻的准分子激光束整形及其研究进展.量子电子学报, 2007, 24(4): 415~419
[23] T.Bizjak, T.Mitra, L.Aschke. Novel high throughput microoptical beam shapers reduce the complexity of macrooptics in hyper-NV illumination systems. SPIE, 2007, 6520: 1~11
[24] Kajava T, Hakola A, Elfstrom H, et a1. Flat-top profile of an excimer laser beam generated using beam splitter gratings. Opt. Commun, 2006, 268: 289~293
[25] Turunen J, Paakkonen P, Kuittinen M, et a1. Diffractive shaping of excimer laser beams. Journal of Modern Optic, 2000, 47(13): 2467~2475
[26] Kopp C, Ravel L, Meyrueis P. Efficient beamshaper homogenizer design combining diffractive optical elements, microlens array and random phase plate. App1 Opt, 1999, 1: 398~403
[27]叶一东,吕百达,蔡邦维.强激光的时间整形和空间整形.激光技术, 1996, 20(6): 324~328
[28] Patrick W.Rhodes, David L.Shealy. Refractive optical systems for irradiance redistribution of collimated radiation:their design and analysis. Appl Opt, 1980,19(20): 3552~3553
[29] HOFFNAG LE J A, JEFFERSON CM. Design and perfor mance of a refractive op tical system that converts a Gaussian to a flatt op beam. Appl Opt, 2000, 39(30): 5488~5499
[30] CHANG S P, KUO JM,LEE Y P, et al. Transfor mation of Gaussian to coherent uniform beams by inverse Gaussian trans mittive filters. Appl Opt, 1998, 37(4): 747~752
[31] DICKEY F M, HOLS WADE S C. Laser beam shap ing: theory and techniques. New York:Marcel, 2000: 163~213
[32] Jiang W. Application of a laser beam profile reshaper to enhance performance of holographic projection systems: [D]. Birmingham: University of Alabama, 1993.
[33]李殿军,梁思远,曹建建.非球面伽利略扩束系统实现激光束空间整形.激光技术, 2008, 32(4): 427~429
[34]曾晓东,安毓英.堆积式大功率激光二极管光束整形.第10届全国光电技术与系统学术光电子技术与信息会议沦文, 2003, 16(增刊): 25~29
[35]高全华,曾晓东,安毓英.大功率半导体激光器光束整形.光电子?激光, 2005, 16(6): 662~664
[36] N.Konforti, Eluarom, S-T.wu. Phase-only modulation with twisted nematie liquid crystal Spatial light modulation. optics Letters, 1988, 13(3): 251~254
[37]陈怀新,隋展,陈祯培等.采用液晶空间光调制器进行激光光束的空间整形.光学学报, 2001, 21(9): 1107~1111
[38]关秀丽.液晶光束控制的研究.长春大学学报, 2006, 16(6): 58~62
[39]王华明,叶玉堂,吴云峰.微小激光曝光区域温度分布均匀化整形方法.光电工程, 2006, 33(4): 55~58
[40]郑建溯,于清旭,关寿华.强激光的靶面均匀辐照和光束匀滑技术.中央民族大学学报, 2008, 17(1): 29~36
[41]刘增水,黄慧杰,路敦武等.无规位相板靶面均匀辐照光学系统研究.强激光与粒子束, 1998, 10(3): 441~444
[42]龚华平,吕志伟,林殿阳.激光束空间整形的研究现状.激光与光电子展, 2005,42(9): 2~5
[43] Xijia Gu, Waleed Mohammed, Li Qian etal. All-Fiber Laser Beam Shaping at 1.0μm Wavelength Region in a Single-mode Fiber. SPIE, 2008, 7099: 1~5
[44] David L.Shealy. Theory of Geometrical Methods for Design of Laser Beam Shaping Systems. SPIE, 2000, 4095: 1~15
[45] Philip H.Malyak. Two-mirror unobscured optical system for reshaping the irradiance distribution of a laser beam. Appl Opt, 1992, 31(22): 4377~4383
[46] J.H.McDermi, T.E.Horton. Reflective Optics for Obtaining Prescribed Irradiative Distributions from Collimated Sources. Appl Opt, 1974, 13 (6) : 1444~1450
[47]郁道银,淡恒英.工程光学. (第二版). (北京):机械工业出版社, 2006. 104~129
[48]李晓彤,岑兆丰.几何光学?相差?光学设计. (第二版). (杭州):浙江大学出版社, 2003. 231~252
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