SPGD算法光束净化中光强起伏对校正效果的影响研究  

Investigation on Influence of Laser Intensity Fluctuation on Beam Cleanup System Based on Stochastic Parallel Gradient Descent Algorithm

作　　者：王小林[1] 王三宏[1] 周朴[1] 马浩统[1] 马阎星[1] 许晓军[1] 刘泽金[1] 赵伊君[1] 

机构地区：[1]国防科技大学光电科学与工程学院,湖南长沙410073

出　　处：《光学学报》2010年第5期1396-1401,共6页Acta Optica Sinica

基　　金：国防科技大学优秀研究生创新(B080702)资助课题

摘　　要：尽管无波前传感自适应光学技术可不受闪烁效应等波前畸变条件的限制,能够有效地补偿高能激光的波前畸变以提高光束质量,但是激光器光强起伏和噪声干扰对校正效果却存在严重的影响。分析了光强起伏和噪声干扰对随机并行梯度下降(SPGD)算法光束净化效果的影响,并进行了相关实验研究。理论分析表明,在光强起伏频率大于等于算法扰动频率时,系统性能随着光强起伏增加而降低;在低频光强起伏时,SPGD算法的抗干扰能力较强。为消除光强起伏对校正效果的影响,提出采用桶中功率作为系统性能评价函数的光束净化方案,理论分析和实验结果都表明,该方案能够有效地消除光强起伏和噪声干扰对校正效果的影响,实现接近校正极限的理想校正效果。Although adaptive optics technique without a wave-front sensor can get rid of the restriction of the terms of wave-front aberrations and is an effective way to compensate the wave-front distortion of the high power laser beam to improve the beam quality,the laser intensity fluctuation and the circuit noise will make the performance of the system deteriorate.The influence of intensity fluctuation and the circuit noise on the results of the beam cleanup system based on stochastic parallel gradient descent（SPGD） algorithm is analyzed,corresponding experiments is done.Result shows that when the frequency of the laser intensity fluctuation is faster than or equal to the disturbance rate,the performance of the system decreases quickly with an increasing amplitude of intensity fluctuation.In the case of low intensity fluctuation rate,the capability of anti-jamming of the SPGD algorithm is excellent.To avoid the influence of the intensity fluctuation and the circuit noise on beam cleanup system,beam cleanup technology based on normalized performance evaluation function： power-in-bucket（PIB） is proposed.Both theoretical and experimental results show that this technology is an effective way to avoid the influence of intensity fluctuation and the circuit noise on beam cleanup system,ideal results approaching the correction limit of the system can be obtained.

关 键 词：激光光学 光束净化 随机并行梯度下降算法 光强起伏 性能评价函数 桶中功率 

分 类 号：O436[机械工程—光学工程]