Photonic Crystal-Based Polarization Converter for Optical Communication Applications

A photonic crystal-based TE to TM polarization converter for integrated optical communication is proposed in this paper. The photonic crystal consists of air circular-holes in slab waveguide. The radius of holes are determined to be 291nm having lattice constant of 640nm using the gap map and band diagram. The polarization converter is composed of an InGaAsP triangular-shaped waveguide on SiO2 substrate. At first, the bandgap wavelengths of two-dimensional structure are determined using finite difference method and then polarization conversion length, polarization conversion efficiency and rotation are determined as a function of the ratio of height to width of the triangle waveguide. The simulation results show a minimum conversion length of 750nm with a conversion efficiency of about 90% could be obtained.