中文摘要：

结合能带图和等频图分析,基于光子晶体自准直效应和光子带隙,设计了一种紧凑、高效的偏振分束器.时域有限差分法（FDTD）模拟表明,该设计可以在一个较大的频率范围f=0.268—0.278（c/a）内实现TE模和TM模的高效（85%）、大角度（90°）分离.在光通讯波长λ=1.55μm,该设计尺寸仅为9μm×9μm.这些特性使其在光通讯领域中具有重要的应用前景.

英文摘要：

We present the design and simulation of an ultra-compact high-efficiency polarization beam splitter （PBS） based on selfcollimation effect and photonic crystal band gap in two dimensional photonic crystals. The splitting properties of the PBS have been numerically studied using the finite difference time domain （FDTD） method. It was shown that a 90° separating angle and efficiency of greater than 85% for TE- and TM- modes over a wide frequency range 0.265-0.275（c/a） can be obtained. The size of PBS is only 9 μm × 9 μm at optical communication wavelength λ = 1.55 μm. These features of the proposed PBS make it a promising candidate in optical communications application.