波前畸变下连续相位板焦斑的计算与实验  

Calculation and Experiment of the Focal Spot Caused by Continuous Phase Plate with Incident Wavefront Distortion

作　　者：温圣林[1] 颜浩[1] 张远航[1] 杨春林[1] 王健[1] 石琦凯[1] 

机构地区：[1]中国工程物理研究院激光聚变研究中心,四川绵阳621900

出　　处：《光学学报》2014年第3期154-159,共6页Acta Optica Sinica

基　　金：国家科技重大专项课题(2013ZX04006011-101)

摘　　要：为了提高惯性约束聚变(ICF)激光装置中连续相位板(CPP)的焦斑性能,建立了波前畸变下连续相位板焦斑的理论计算和分析模型,并根据CPP使用条件搭建了三倍频大口径CPP远场离线测试系统。对加工330mm×330mm口径的CPP和波前畸变元件进行了理论计算和离线测试实验的对比研究。理论计算和实测的焦斑形貌、参数数值均非常一致,验证了计算模型的正确性和实验系统的可靠性。理论和实验结果一致表明,波前畸变对CPP焦斑性能的影响非常严重,当弥散斑为0.5倍CPP焦斑时,畸变量已对CPP焦斑形貌产生了很大影响,能量利用率下降值大于4%,焦斑半径增大超过20μm,陡边阶数下降1.3阶,不均匀性均方根(RMS)值下降6%,旁瓣份额增长超过0.5%。In order to improve the focal spot performance caused by continuous phase plate （CPP） in the laser facility for inertial confinement fusion （ICF） system, a theoretical calculation and analyse model for CPP with wavefront distortion is proposed, and off-line measurement system with three harmonic generation laser for the far-field intensity is built up according to the working conditions of CPP in the laser system. The comparison between calculation and measurement for the 330 mm X 330 mm CPP and wavefront distortion component is carried out. The pattern and parameters are matched very well, so the correctness of calculation model and the credibility of measurement system are certified. The results show that the CPP＇s focal spot performance is effected by the incident wavefront distortion severely. The CPP＇s focal spot is changed largely when the disc of confusion caused by wavefront distortion is equal to half of the focal size caused by CPP. The changes include that the capacity usage ratio descends more than 4 %, the focal spot radius increases over 20 μm, the super-Gauss order of the focal spot profiles reduces 1.3, the root mean square （RMS） value of inhomegeneity reduces 6 %, and the percentage of side lobe increases over 0.5 %.

关 键 词：光学器件 连续相位板 焦斑 波前畸变 光束匀滑 惯性约束聚变 

分 类 号：O435.2[机械工程—光学工程]