光谱色散和分布式相位板联用对靶面辐照均匀性的改善  

Improvement of Target Irradiation Uniformity Using Spectral Dispersion and Distributed Phase Plate

作　　者：曹国威[1] 石鹏[1] 张晓波[2] 邬融[3] 周申蕾[3] 李永平[1] 

机构地区：[1]中国科技大学光学与光学工程系,安徽合肥230026 [2]中国科技大学国家同步辐射实验室,安徽合肥230026 [3]中国科学院上海光学精密机械研究所高功率激光物理联合实验室,上海201800

出　　处：《中国激光》2011年第10期29-34,共6页Chinese Journal of Lasers

摘　　要：通过对分布式相位板和光谱色散匀滑技术联用的模拟计算,分析了联用实验中焦斑的变化,论证了非设计采样点光强的不可控性对焦斑匀滑质量的损害。模拟结果证实了光谱色散匀滑技术对色散方向上的焦斑均匀性的改善,焦斑不均匀性由58.30%降为19.50%。通过分析焦斑不均匀性与光谱色散匀滑积分时间的关系,发现5~6个光谱色散匀滑调制周期时得到最优匀滑效果。对焦斑频谱的分析显示,光谱色散匀滑技术可以有效抑制由非设计采样点光强引入的高频成分,26.3μm内的光强调制被平滑,同时很好地保持了由分布式相位板决定的焦斑低频包络,在实验与模拟中均得到很好验证。为进一步的分布式相位板与光谱色散匀滑技术联用设计提供了理论依据。The uniformity of focal-spot pattern is analyzed by the simulation employing spectral dispersion and distributed phase plate in the laser chain.The uncontrollability of intensity at non-sampling points in the distributed phase plate design causes the loss of uniformity.The simulation confirms the improvement of target irradiation by spectral dispersion;the nonuniformity of focal spot decreases from 58.30% to 19.50%.The relation between nonuniformity and integration time shows that the optimal integration time is 5~6 modulation periods of spectral dispersion.The high spatial frequency of focal spot caused by intensity at non-sampling points is reduced by spectral dispersion smoothing;the intensity fluctuation within 26.3 μm can be eliminated.The results above are confirmed by simulation and experiments,providing theoretical guidance for the next design of distributed phase plate combining with spectral dispersion.

关 键 词：衍射 分布式相位板 光谱色散匀滑 激光辐照均匀性 焦斑频谱分析 

分 类 号：O433.54[机械工程—光学工程]