产生均匀焦斑的组合式衍射光学阵列器件

Composite Diffractive Optics Array Element for Generating a Uniform Focal Spot

提出并设计了一种不同尺寸的方形单元组成的衍射光学陈列器件，其外形逼近于圆形，以产生平顶、陡边、小劳瓣的焦班光强分布。对输入圆形光束有较大的填充因子，充分利用了光能。在设计上将二维简化为一维，且加工简单。基于爬山法和模拟退火法相结合的混合算法，设计了器件的位相分布。模拟计算结果表明了这种方法的有效性。

In this paper, a kind of composite diffractive optics array element, whose shape isapproximately circuIar by containing some series of square units with different sizes, isdesigned to obtain a focal spot with flat top, steep edges and low sidelode intensitydistribution. For an incident laser beam with circular shape, a large filling factor can bereallzed and light energy can be sufficiently used. Two dimensions are converted to onedimension to simplify the design and manufacturing. Hybrid algorithm based on hill-climbing and stimulated annealing is utilized for phase design. Simulated results show thevalidity of this kind of method.