用于共孔径相干合成的衍射光学元件设计  

Design of diffractive optical elements for filled-aperture coherent beam combining

作　　者：颜宏[1,2,3] 张卫[1] 叶一东[1,2] 陈黎[1] 田飞[1] 

机构地区：[1]中国工程物理研究院应用电子学研究所,四川绵阳621900 [2]中国工程物理研究院高能激光科学与技术重点实验室,四川绵阳621900 [3]中国工程物理研究院研究生部,北京100088

出　　处：《强激光与粒子束》2015年第6期6-11,共6页High Power Laser and Particle Beams

基　　金：中国工程物理研究院高能激光与科学技术重点实验室基金项目(HEL2014-07)

摘　　要：分析了衍射光学元件实现共孔径相干合成的物理过程,建立了基于衍射光学元件的共孔径相干合成数学模型,推导了合成光束复振幅与入射光束和衍射光学元件相位分布之间的关系。提出用合成光束强度分布的均匀性作为评价函数的优化方法,获得了一维衍射合束器的相位分布。与文献报道的衍射光学元件分束器相比,可获得更高的合成效率。采用模拟退火算法结合随机并行梯度下降算法优化合束器设计,提高了计算效率,获得了多束衍射合束器的相位分布和合成效率。分析了单子束失效及合束器像差对合成效率的影响,结果表明:随着合束数量的增加,单子束失效对合成效率的影响逐渐减小;若使合成效率退化小于5%,衍射光学元件的波像差均方根值应控制在λ/28以内。The physical process of filled-aperture coherent beam combining （CBC） using diffractive optical elements （DOEs） is analyzed. The mathematical model of C13C based on DOEs is build up, and the relationship between the complex amplitude of the combined beam and the phase distribution of the DOEs is deduced. The uniformity of the intensity of combined beam is used as the evaluation function of the iteration, and the phase distributions of the one-dimensional diffractive beam combiners are calcu- lated. Compared with the reported DOEs beam splitters, these beam combiners can achieve higher combining efficiency. The phase distributions of the beam combiners are optimized using both simulated annealing algorithm and stochastic parallel gradient descent algorithm, and the computational efficiency is significantly improved. The phase distribution and combining efficiency of multi-beam diffractive beam combiners are presented. The impacts of single disabled beam and surface error of the DOEs on the combining efficiency are analyzed. The simulation results expose that with the increasing number of component beams the impact of single disabled beam on combining efficiency decreases, and the RMS wavefront error of the DOEs should be less than 1/28 of the wavelength in order to make combining efficiency degradation less than 5 %.

关 键 词：衍射光学元件 衍射分束器 相干合成 模拟退火算法 随机并行梯度下降算法 衍射效率 

分 类 号：TN2[电子电信—物理电子学] V43[航空宇航科学与技术—航空宇航推进理论与工程]