High-efficiency polarization beam splitter based on a self-collimating photonic crystal

Abstract

We present what we believe to be a novel high-efficiency photonic crystal polarization beam splitter that consists of a polarizing photonic crystal slab embedded in a two-dimensional self-collimating square lattice photonic crystal of air holes in silicon. The polarizing photonic crystal slab with the same lattice constant as the self-collimating photonic crystal background exhibits not only high reflection for transverse electric (TE) and high transmission for transverse magnetic (TM) polarization, but also high extinction ratios for both two-polarization output channels. Moreover, high-efficiency common antireflection structures for both TE and TM polarizations are applied at the input and output ends of the photonic crystal polarization beam splitter, thereby enabling one to achieve a highly efficient photonic crystal polarization beam splitter. It is shown that the primary transmissions exceeding 94.04% for TE and 92.39% for TM polarization output channels are achieved through the proposed photonic crystal polarization beam splitter.