多色光谱色散匀滑技术参数对集束辐照特性的影响
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摘要
针对惯性约束聚变装置中多色光谱色散匀滑技术在集束中的运用,提出了对电光调制器、色散光栅和连续相位板(CPP)等主要单元器件进行独立设计和优化的思路。基于这一思路,分别模拟和分析了电光调制器、色散光栅和CPP等单元器件的参数对集束辐照特性的影响。提出了优化的多色光谱色散匀滑方案参数,并仿真了束匀滑参数对激光束纵向成丝特性的影响。结果表明,通过优化不同子束的电光相位调制器和色散光栅参数,可以进一步改善靶面的辐照均匀性。当集束中各子束采用不同的CPPs时,焦斑均匀性得到有效改善,热斑比例明显降低。采用功率谱密度对激光束的光束质量进行分析,结果表明多色光谱色散匀滑方案能有效降低峰值强度,使光强分布更加均匀,从而有利于抑制激光束成丝。
Aimed at the application of smoothing of multi-color spectral dispersion in inertial confinement fusion facilities,an independent design and optimization method for main unit components,including electro-optic modulators,dispersion gratings and continuous phase plates(CPP)and so forth,is proposed.The effects of parameters of electro-optic phase modulators,dispersion gratings and the CPP on the laser-quad irradiation characteristics are simulated and analyzed.The parameters of optimized smoothing of multi-color spectral dispersion are proposed,and the effect of the smoothing parameters on the characteristics of longitudinal filaments of lasers is simulated.Results indicate that the irradiation uniformity on the target surface can be further improved when we optimize the parameters of electro-optical modulator and dispersion grating of different sub-beams.When different CPPs are implemented for different sub-beams in the laser-quad,the focal-spot uniformity can be improved effectively and the proportion of hot spots can be decreased significantly.Moreover,the beam quality of the laser beam is analyzed by the power spectral density.The simulation results show that the smoothing of multi-color spectral dispersion can effectively decrease the peak intensity and make the light intensity distribution more uniform,which is benefit to suppress filaments of laser beams.
Aimed at the application of smoothing of multi-color spectral dispersion in inertial confinement fusion facilities,an independent design and optimization method for main unit components,including electro-optic modulators,dispersion gratings and continuous phase plates(CPP)and so forth,is proposed.The effects of parameters of electro-optic phase modulators,dispersion gratings and the CPP on the laser-quad irradiation characteristics are simulated and analyzed.The parameters of optimized smoothing of multi-color spectral dispersion are proposed,and the effect of the smoothing parameters on the characteristics of longitudinal filaments of lasers is simulated.Results indicate that the irradiation uniformity on the target surface can be further improved when we optimize the parameters of electro-optical modulator and dispersion grating of different sub-beams.When different CPPs are implemented for different sub-beams in the laser-quad,the focal-spot uniformity can be improved effectively and the proportion of hot spots can be decreased significantly.Moreover,the beam quality of the laser beam is analyzed by the power spectral density.The simulation results show that the smoothing of multi-color spectral dispersion can effectively decrease the peak intensity and make the light intensity distribution more uniform,which is benefit to suppress filaments of laser beams.
引文
[1]Li P,Ma C,Su J Q,et al.Analysis of laser optimized spectrum for smoothing the focused spot by temporal and special method[J].Chinese Journal of Lasers,2008,35(4):534-538.李平,马驰,粟敬钦,等.时域与空域结合实现光束匀滑的光谱优化分析[J].中国激光,2008,35(4):534-538.
[2]Dixit S N,Thomas I M,Woods B W,et al.Random phase plates for beam smoothing on the Nova laser[J].Applied Optics,1993,32(14):2543-2554.
[3]Yang C L,Yan H,Wang J,et al.A novel design method for continuous-phase plate[J].Optics Express,2013,21(9):11171-11180.
[4]Xiao Q Y,LüC,Zhang R Z.Influence of surface characteristics of continuous phase plate on far field distribution[J].High Power Laser and Particle Beams,2014,26(10):102003.肖谦裔,吕晨,张蓉竹.连续相位板面形特性对远场分布的影响[J].强激光与粒子束,2014,26(10):102003.
[5]Wen S G,Tang C X,Zhang Y H,et al.Effects of least spatial period on the fabrication and performance of continuous phase plate[J].Chinese Journal of Lasers,2015,42(9):0908001.温圣林,唐才学,张远航,等.最小空间周期对连续相位板加工和性能的影响[J].中国激光,2015,42(9):0908001.
[6]Feng Y J,Wang Z.Influence of different distorted wavefronts on continuous phase plate smoothing focal spot[J].Laser&Optoelectronics Progress,2015,52(7):072204.冯友君,王忠.不同波前畸变对连续相位板焦斑的影响[J].激光与光电子学进展,2015,52(7):072204.
[7]Zhang R.Research on precisecontrol technologies of intensity distribution on target of high power laser facilities[D].Hefei:University of Science and Technology of China,2013.张锐.高功率激光装置靶面光强分布精密控制技术研究[D].合肥:中国科学技术大学,2013.
[8]Lehmberg R H,Schmitt A J,Bodner S E.Theory of induced spatial incoherence[J].Journal of Applied Physics,1987,62(7):2680-2701.
[9]Regan S P,Marozas J A,Craxton R S,et al.Performance of 1-THz-bandwidth,two-dimensional smoothing by spectral dispersion and polarization smoothing of high-power,solid-state laser beams[J].Journal of the Optical Society of America B,2005,22(5):998-1002.
[10]Xiao J,LüB D.Characteristics of polarization control plate smoothing interference speckles[J].Chinese Journal of Lasers,2000,27(7):627-632.肖峻,吕百达.偏振控制板对干涉斑纹的匀滑特性[J].中国激光,2000,27(7):627-632.
[11]Haynam C A,Wegner P J,Auerbach J M,et al.National Ignition Facility laser performance status[J].Applied Optics,2007,46(16):3276-3303.
[12]Fleurot N,Cavailler C,Bourgade J L.The Laser Mégajoule(LMJ)Project dedicated to inertial confinement fusion:Development and construction status[J].Fusion Engineering and Design,2005,74(1/2/3/4):147-154.
[13]Pennington D M,Henesian M A,Wilcox R B,et al.Four-color beam smoothing irradiation system for laser-plasma interaction experiments at LLNL[C].SPIE,1995,2633:228256.
[14]Zhong Z Q,Zhou B J,Ye R,et al.A novel scheme of beam smoothing using multi-central frequency and multi-color smoothing by spectral dispersion[J].Acta Physica Sinica,2014,63(3):035201.钟哲强,周冰洁,叶荣,等.多频多色光谱角色散束匀滑新方案[J].物理学报,2014,63(3):035201.
[15]Wen P,Li Z L,Zhong Z Q,et al.Parameters optimization for multi-color multi-central frequency smoothing by spectral dispersion[J].Acta Optica Sinica,2015,35(6):0614001.文萍,李泽龙,钟哲强,等.多色、多频光谱角色散匀滑技术的参数优化[J].光学学报,2015,35(6):0614001.
[16]Zhong Z Q,Zhang B.Beam smoothing characteristics of multi-central frequency and multi-color smoothing by spectral dispersion[J].Applied Optics,2014,53(10):2020-2025.
[17]Wang J,Hou P C,Zhang B.A new scheme of spectral dispersion smoothing based on hybrid grating[J].Acta Physica Sinica,2016,65(20):0204201.王健,侯鹏程,张彬.基于复合型光栅的光谱色散匀滑新方案[J].物理学报,2016,65(20):0204201.
[18]Lindl J D,Amendt P,Berger R L,et al.The physics basis for ignition using indirect-drive targets on the National Ignition Facility[J].Physics of Plasmas,2004,11(2):339-491.
[19]Williams E A.New findings on the control of filamentation of intense laser beams propagating in underdense plasma[J].Physics of Plasmas,2006,13(5):056310.
[20]Zhou B J,Zhong Z Q,Zhang B.Influence of beam moving characteristics on smoothing effect of focal spot[J].Acta Physica Sinica,2012,61(21):214202.周冰洁,钟哲强,张彬.光束运动特性对焦斑束匀滑效果的影响[J].物理学报,2012,61(21):214202.
[21]Marozas J A.Fourier transform-based continuous phase-plate design technique:A high-pass phase-plate design as an application for OMEGA and the National Ignition Facility[J].Journal of the Optical Society of America A,2007,24(1):74-83.
[22]Key M H,Campbell E M,Cowan T E,et al.The potential of fast ignition and related experiments with a petawatt laser facility[J].Journal of Fusion Energy,1998,17(3):231-236.
[23]Peng Z T,Jing F,Liu L Q,et al.Power spectra density estimation of quality of the laser beam passing through an self-focusing media[J].Acta Physica Sinica,2003,52(1):87-90.彭志涛,景峰,刘兰琴,等.自聚焦激光束光束质量评价的功率谱密度方法[J].物理学报,2003,52(1):87-90.
[2]Dixit S N,Thomas I M,Woods B W,et al.Random phase plates for beam smoothing on the Nova laser[J].Applied Optics,1993,32(14):2543-2554.
[3]Yang C L,Yan H,Wang J,et al.A novel design method for continuous-phase plate[J].Optics Express,2013,21(9):11171-11180.
[4]Xiao Q Y,LüC,Zhang R Z.Influence of surface characteristics of continuous phase plate on far field distribution[J].High Power Laser and Particle Beams,2014,26(10):102003.肖谦裔,吕晨,张蓉竹.连续相位板面形特性对远场分布的影响[J].强激光与粒子束,2014,26(10):102003.
[5]Wen S G,Tang C X,Zhang Y H,et al.Effects of least spatial period on the fabrication and performance of continuous phase plate[J].Chinese Journal of Lasers,2015,42(9):0908001.温圣林,唐才学,张远航,等.最小空间周期对连续相位板加工和性能的影响[J].中国激光,2015,42(9):0908001.
[6]Feng Y J,Wang Z.Influence of different distorted wavefronts on continuous phase plate smoothing focal spot[J].Laser&Optoelectronics Progress,2015,52(7):072204.冯友君,王忠.不同波前畸变对连续相位板焦斑的影响[J].激光与光电子学进展,2015,52(7):072204.
[7]Zhang R.Research on precisecontrol technologies of intensity distribution on target of high power laser facilities[D].Hefei:University of Science and Technology of China,2013.张锐.高功率激光装置靶面光强分布精密控制技术研究[D].合肥:中国科学技术大学,2013.
[8]Lehmberg R H,Schmitt A J,Bodner S E.Theory of induced spatial incoherence[J].Journal of Applied Physics,1987,62(7):2680-2701.
[9]Regan S P,Marozas J A,Craxton R S,et al.Performance of 1-THz-bandwidth,two-dimensional smoothing by spectral dispersion and polarization smoothing of high-power,solid-state laser beams[J].Journal of the Optical Society of America B,2005,22(5):998-1002.
[10]Xiao J,LüB D.Characteristics of polarization control plate smoothing interference speckles[J].Chinese Journal of Lasers,2000,27(7):627-632.肖峻,吕百达.偏振控制板对干涉斑纹的匀滑特性[J].中国激光,2000,27(7):627-632.
[11]Haynam C A,Wegner P J,Auerbach J M,et al.National Ignition Facility laser performance status[J].Applied Optics,2007,46(16):3276-3303.
[12]Fleurot N,Cavailler C,Bourgade J L.The Laser Mégajoule(LMJ)Project dedicated to inertial confinement fusion:Development and construction status[J].Fusion Engineering and Design,2005,74(1/2/3/4):147-154.
[13]Pennington D M,Henesian M A,Wilcox R B,et al.Four-color beam smoothing irradiation system for laser-plasma interaction experiments at LLNL[C].SPIE,1995,2633:228256.
[14]Zhong Z Q,Zhou B J,Ye R,et al.A novel scheme of beam smoothing using multi-central frequency and multi-color smoothing by spectral dispersion[J].Acta Physica Sinica,2014,63(3):035201.钟哲强,周冰洁,叶荣,等.多频多色光谱角色散束匀滑新方案[J].物理学报,2014,63(3):035201.
[15]Wen P,Li Z L,Zhong Z Q,et al.Parameters optimization for multi-color multi-central frequency smoothing by spectral dispersion[J].Acta Optica Sinica,2015,35(6):0614001.文萍,李泽龙,钟哲强,等.多色、多频光谱角色散匀滑技术的参数优化[J].光学学报,2015,35(6):0614001.
[16]Zhong Z Q,Zhang B.Beam smoothing characteristics of multi-central frequency and multi-color smoothing by spectral dispersion[J].Applied Optics,2014,53(10):2020-2025.
[17]Wang J,Hou P C,Zhang B.A new scheme of spectral dispersion smoothing based on hybrid grating[J].Acta Physica Sinica,2016,65(20):0204201.王健,侯鹏程,张彬.基于复合型光栅的光谱色散匀滑新方案[J].物理学报,2016,65(20):0204201.
[18]Lindl J D,Amendt P,Berger R L,et al.The physics basis for ignition using indirect-drive targets on the National Ignition Facility[J].Physics of Plasmas,2004,11(2):339-491.
[19]Williams E A.New findings on the control of filamentation of intense laser beams propagating in underdense plasma[J].Physics of Plasmas,2006,13(5):056310.
[20]Zhou B J,Zhong Z Q,Zhang B.Influence of beam moving characteristics on smoothing effect of focal spot[J].Acta Physica Sinica,2012,61(21):214202.周冰洁,钟哲强,张彬.光束运动特性对焦斑束匀滑效果的影响[J].物理学报,2012,61(21):214202.
[21]Marozas J A.Fourier transform-based continuous phase-plate design technique:A high-pass phase-plate design as an application for OMEGA and the National Ignition Facility[J].Journal of the Optical Society of America A,2007,24(1):74-83.
[22]Key M H,Campbell E M,Cowan T E,et al.The potential of fast ignition and related experiments with a petawatt laser facility[J].Journal of Fusion Energy,1998,17(3):231-236.
[23]Peng Z T,Jing F,Liu L Q,et al.Power spectra density estimation of quality of the laser beam passing through an self-focusing media[J].Acta Physica Sinica,2003,52(1):87-90.彭志涛,景峰,刘兰琴,等.自聚焦激光束光束质量评价的功率谱密度方法[J].物理学报,2003,52(1):87-90.