焦斑形态精细化设计及其性能分析

 对实现焦斑形态控制的衍射光学器件进行了精细化设计,模拟计算结果表明,可同时满足洞口附近旁瓣光强峰值不超过主瓣平均光强的0.01%,且主瓣顶部不均匀性小于10%。选取不同的采样间隔对比说明了精细化设计相对于传统设计,能真实准确地获得焦斑形态的性能参数。最后,采用功率谱密度(PSD)方法初步分析了器件几何结构与焦斑性能,特别是旁瓣间的对应关系。

Precise design of the focused spot and its performance analysis

In this paper, the precise design of the diffractive optical element (DOE) is completed to control the shape of the focused spot. By using the hybrid algorithm, merging Hill climbing with Simulated Annealing, and adjusting the weight factor in the optimization, the DOE can realize high uniformity at the main lobe (non uniformity is less than 10%) and no "blocking" effect around the hole (the ratio between the peak intensity around the hole and the average value of the main lobe is less than 0.01%) simultaneously. Different sampling intervals are used to examine the performance of the DOE, and the simulated results show that the calculated performance parameters are true and accurate with the precise design, and the fence effect induced by discretization with the traditional sampling interval is avoided. Finally, the PSD (power spectral density) method is applied to analyze the relationship between the geometrical structure of the DOE and the performance of the focused spot, especially the side lobe around the hole.