基于二维结构薄膜的偏振选择相位光栅的研究  

Polarization dependent phase grating based on two-dimensional structured thin films

作　　者：厉以宇[1] 王媛媛[1] 陈浩[1] 朱德喜[1] 胡川[1] 瞿佳[1] 

机构地区：[1]温州医学院眼视光学院,卫生部视觉科学研究重点实验室,温州325027

出　　处：《物理学报》2010年第7期5110-5115,共6页Acta Physica Sinica

基　　金：浙江省科技计划(批准号:2009C31136;2007C11083);温州市科技计划(批准号:G20070082)资助的课题~~

摘　　要：利用二维结构薄膜构建了具有偏振选择特性的新型相位光栅,借助严格耦合波分析(RCWA)方法计算了光栅各级衍射强度随入射光波长及入射角的变化,发现在垂直入射情况下,波长600—640nm范围内,相位光栅对横向电学(TE)模主要产生0级衍射,而对横向磁学(TM)模产生±1级衍射,在波长633nm处,0级衍射光的偏振消光比为109.8,±1级衍射光的偏振消光比为334.6.利用时域有限差分方法对这种相位光栅的偏振分束现象进行了模拟,偏振分离角在玻璃基板内可以达到10°左右,最后模拟了入射角为23°时光栅对不同偏振态入射光的衍射效果,并与RCWA计算结果和光栅方程计算结果进行了比对.The new phase grating based on two-dimensional structured thin films is reported.The rigorous coupled-wave analysis（RCWA） is employed to calculate the diffraction efficiency which varies with incident wavelength and angle.According to the result obtained by using RCWA,when the wavelength ranges from 600 to 640 nm,TE mode and TM mode can be diffracted in the transmitted 0th and ± 1st orders,respectively,at normal incident angle.For example,at the wavelength of 633 nm,the polarization extinction ratio of 0th order is I0,TE/I0,TM=109.8,and the polarization extinction ratio of ±1st order is I±1,TM/I±1,TE=334.6.This polarizing beam splitting phenomenon is confirmed by theoretical simulation with finite-difference time-domain method,which shows that TE mode and TM mode can be separated by an angle of about 10° in glass substrate.The same simulation method is performed for the diffraction at incident angle of 23° in order to compare with the results from RCWA and grating equation calculation.

关 键 词：偏振 结构薄膜 相位光栅 

分 类 号：TN253[电子电信—物理电子学]