锯齿型衍射光阑的优化设计与制作

在传统几何光阑基础上，利用微细加工技术在其特定区域制作衍射微结构，则可获得既能控制光束大小又能实现光束整形的衍射光阑.针对高功率激光放大系统前端光束形态控制的需求，对可产生平顶超高斯光束的锯齿型衍射光阑的优化设计理论进行了研究，提出引入均方误差和顶部不均匀度两个参数作为优化设计的评价依据，并在此基础上对影响光阑光束控制效果的衍射微结构进行了深入分析，获得了锯齿型衍射光阑关键参数的优化设计方法.最后，提出采用镀膜结合光学光刻的方法，制作了锯齿型衍射光阑.

Optimization and manufacture of serrated diffractive aperture

Based on traditional geometrical aperture, using micro fabrication technology, diffractive aperture with diffractive tenuous structure in the given area is gained. The aperture can be used in both caliber controlling and beam shaping. According to the demand of high power laser system, the theory of optimization of serrated diffractive aperture is studied. Furthermore, using two parameters of root mean square error and top inhomogeneity, the effect of diffractive tenuous structure on controlling of laser beam is analyzed. Then, the method of optimization of serrated diffractive aperture is presented. Finally, with the method of coating and lithography, serrated diffractive aperture is manufactured.