偶数束亚波长Dammann光栅结构的矢量衍射优化设计

传统的基于标量衍射理论方法设计的Dammann光栅衍射效率较低。基于严格耦合波理论和遗传算法,介绍了亚波长结构偶数分束数Dammann光栅的设计方法。利用优化程序设计了多个光栅结构并对设计结果进行了分析,讨论了关键参数的选取及设计参数和光波偏振态的变化对分束效率和均匀性的影响。仿真结果表明所设计的偶数束Dammann光栅分束均匀性很好并且分束总效率均达到93%以上,而零级衍射效率均降到了0.64%以下,达到了较好的去零级衍射的效果。

Optimal design of subwavelength structure Dammann gratings with even diffractive beams grating based on vector diffraction theory

Diffraction efficiency of the conventional Dammann grating is low designed by using the scalar diffractive theory.A design method of subwavelength structure Dammann grating with even diffractive beams is described based on the rigorous couple wave theory and genetic algorithm.We designed several Dammann gratings by optimal program,and analyzed the design results.We also discussed the choice of the key parameter and the influence of design parameter and different polarized light wave to diffractive efficiency and uniformity of diffractive beams.The emulational results indicated that the Dammann grating with even diffractive beams had the diffraction efficiency of more than 93% and had the high uniformity,and zero-order diffraction efficiency was less than 0.64%,a preferable result of eliminating zero-order diffraction efficiency was achieved.