光子学报, 2010, 39 (10): 1795, 网络出版: 2010-12-07
二维高效光子晶体偏振分束器
Efficient Polarization Beam Splitter Based on Two-dimensional Photonic Crystal
光子晶体 蜂窝格子 偏振分束器 消反层 Photonic crystals Honeycomb lattice Polarization Beam Splitter(PBS) Anti-Reflection Layer(ARL)
摘要
为解决透射型偏振分束器透射效率低、高入射角度依赖的缺点,利用二维光子晶体平板设计了一种高效偏振分束器.采用的光子晶体是由空气中周期性排列的蜂窝格子GaAs介质柱构成.该偏振器对一种偏振光(TE偏振)正常折射,而对另一种偏振(TM偏振)负折射,从而实现两种偏振模式在空间上分离.为提高其透射效率,在光子晶体平板表面引入了消反层,并对相关参量进行优化.二维有限时域差分模拟结果显示,在较宽的角度范围内(约20°),约化圆频率处在ω=0.20~0.23×2πc/a范围内,分束器对TE和TM偏振光的透射强度都能达到95%以上.
Abstract
To overcome disadvantages of low transmission efficiency and high dependence on the incident angle for the transmitting type polarization beam splitter (PBS), a highly efficient PBS based on a two-dimensional photonic crystal slab is proposed, which consists of a honeycomb lattice of GaAs cylinders in air. The PBS has a normal refraction for TE polarization and a negative refraction for the other polarization (TM polarization) so that it can separate these two polarization beams totally in space. Anti-reflection layers (ARLs) at the surfaces of the photonic crystal slab are introduced and relevant parameters are optimized to improve the transmission efficiency. Two-dimensional finite difference time domain (FDTD) simulation results show that, in a wide angle range (about 20°), in a normalized circular frequency range of ω=0.20~0.23×2πc/a, the transmission intensity can reach over 98% for both TE and TM polarization.
孙露露, 沈义峰, 王娟, 周杰, 张园, 唐刚. 二维高效光子晶体偏振分束器[J]. 光子学报, 2010, 39(10): 1795. SUN Lu-lu, SHEN Yi-feng, WANG Juan, ZHOU Jie, ZHANG Yuan, TANG Gang. Efficient Polarization Beam Splitter Based on Two-dimensional Photonic Crystal[J]. ACTA PHOTONICA SINICA, 2010, 39(10): 1795.