Polarization optical bridge based on two-dimensional photonic crystals and Bragg effect of defect rods

摘要

We propose two types of polarization optical bridges (POBs) that combine two-dimensional square-lattice photonic crystal cross-waveguides containing Bragg defects. The Bragg defects provide polarization selection. A very low polarization cross talk was obtained in the POBs. Using the finite element method, it is demonstrated that these structures can achieve a degree of polarization of almost 1, a polarization extinction ratio ＞32 dB, and an insertion loss ＜0.3 dB over a wide range of wavelengths. Such structures can be used for separating different polarization modes while maintaining polarization independence. Moreover, they have great potential for application in large-scale optical integrated circuits.