中文摘要：

基于严格耦合波理论，提出了金属介质膜光栅（MMDG）的带宽评价函数和波长偏离评价函数，并对宽光谱MMDG结构参数进行优化。数值模拟分析表明，当MMDG的槽深为290nm、剩余厚度为10nm、占空比取0．28和入射角为60。时，对以1053nm为中心波长的TE波，其一1级衍射效率优于97％的带宽达到190nm。对结构参数分析表明，设计的宽光谱MMDG工艺容差比较大，满足光栅的制备要求。

英文摘要：

Based on the rigorous coupled-wave theory, the merit functions for the diffraction bandwidth and variance from center wavelength are proposed to analyze the diffraction property of broadband metal multi-layer dielectric grating （MMDG）. When the groove depth, residual thickness, duty cycle and inci- dent angle are 290 nm, 10 nm,0.28 and 60° respectively, the optimized MMDG exhibits an ultra-broad- band top-hat diffraction spectrum with average efficiency exceeding 97 % over the 190 nm wavelength range centered at 1053 nm with TE mode. Numerical simulation shows that the optimized MMEG has excellent fabrication tolerance. The optimized broadband MMI2）G should be useful for chirped pulse compression.