非对称偏振分束光栅的矢量衍射优化设计

基于严格耦合波理论分析了一种非对称偏振分束光栅的设计。这种偏振分束光栅分别在1级和0级衍射级次上衍射TE和TM偏振波。介绍了利用遗传算法设计偏振分束光栅的方法,并给出了优化实例。仿真结果表明:在设计波长为1.55时,TE偏振波在1级的衍射效率大于93%,TM偏振波在0级的衍射效率大于99%,此时1级和0级的透射消光比分别达到了9914.1和46841.5。通过对设计结果的分析发现,该偏振分束光栅在设计波长附近100nm的波长范围内都具有较高的消光比(大于100),达到了较好的偏振分束效果。

Optimal design of asymmetrical polarizing beam splitters based on rigorous couple wave theory

Design of an asymmetrical polarizing beam splitters is described based on rigorous couple wave theory,where TE and TM polarized waves are mainly diffracted in the 1st and 0th orders,respectively.Design method of polarizing beam splitters using the genetic algorithm is presented and an example is shown.The result indicates that the diffractive efficiency of TE and TM polarized waves in the 1st and 0th orders are more than 93% and 99%,respectively,when the light wavelength is 1.55,here the extinction ratio of TE and TM polarized waves in the 1st and 0th transmissive orders are 9914.1 and 46841.5.Analysis also shows that the grating have the extinction ratio of more than 100 in the 100 wavelength interval near the design wavelength,and a preferable effect of polarizing beam splitter is achieved.