Wang Jianpeng, Jin Yunxia, Ma Jianyong, Sun Tianyu, Jing Xufeng
Key Laboratory of Material Science and Technology for High Power Lasers, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
Appl Opt. 2010 Jun 1;49(16):2969-78. doi: 10.1364/AO.49.002969.
We report on two effective methods, multiparameter optimization and local optimization combined with the diffraction bandwidth merit function, to design a broadband pulse compression grating (PCG), and we present broadband, high-efficiency PCGs based on both the multilayer dielectric grating (MDG) and metal-multilayer dielectric grating (MMDG) models. For MDG, the average diffraction efficiency is higher than 97.5% for TE polarization light over the 100 nm bandwidth centered at 800 nm. Moreover, a novel multilayer structure, which comprises higher index material in the high-reflectivity mirror and relatively lower index material on top, is first proposed to yield higher average efficiency, broader bandwidth, and excellent fabrication tolerance. For MMDG, it exhibits an ultrabroadband top-hat diffraction spectrum with average efficiency exceeding 97% over the 200 nm wavelength wide centered at 1053 nm. In addition, the MMDG structure, which has the best tolerance for grating fabrication, is determined by investigating characteristics of MMDGs with different thin-film structures.
我们报告了两种有效的方法，即多参数优化以及结合衍射带宽优值函数的局部优化，用于设计宽带脉冲压缩光栅（PCG），并且我们展示了基于多层介质光栅（MDG）和金属 - 多层介质光栅（MMDG）模型的宽带、高效PCG。对于MDG，在以800nm为中心的100nm带宽内，TE偏振光的平均衍射效率高于97.5%。此外，首次提出了一种新型多层结构，其在高反射镜中包含较高折射率材料，顶部为相对较低折射率材料，以实现更高的平均效率、更宽的带宽和出色的制造容差。对于MMDG，它在以1053nm为中心的200nm波长范围内呈现超宽带平顶衍射光谱，平均效率超过97%。此外，通过研究不同薄膜结构的MMDG的特性，确定了对光栅制造具有最佳容差的MMDG结构。
