基于耦合波理论设计偏振分束光栅

Designing polarizing beam splitters based on rigorous couple-wave analysis

亚波长周期结构光栅具有传统光栅所不具有的特殊性质。针对通信中常用的1.55μm光波,采用严格耦合波理论分析了亚波长光栅的偏振分光特性,设计了对应的偏振分束光栅。所设计的光栅在入射角为56°时,透射消光比和反射消光比都大于9000,且在1.27μm^1.67μm全光波段内,入射角在51°~57°之间时,透射消光比和反射消光比都大于100,达到了宽带宽、宽角度以及透射消光比和反射消光比都较高的要求。

Gratings with subwavelength periodic structures have some unique properties that conventional gratings do not possess. For the optical wave of 1. 55μ used widely in commtmication system, the polarizing beam splitting performance of subwavelength grating was analyzed using the rigorous couple-wave theory and the corresponding polarizing beam splitter was designed. The extinction ratios for both reflection side and transmission side are better than 9000 when the designed grating works at an incident angle of 56°. At the .same time, the extinction ratios were better than 100 when the incident wavelength was varied in the range from 1.27μm to 1.67μm and the incident angle is in the range from 51° to 57°, which met the expectations for wide band, wide angle and high extinction ratios.