Design of Photonic Crystal Polarization Splitter on InP Substrate

In this article, we suggested a novel design of polarization splitter based on coupler waveguide on InP substrate at 1.55mm wavelength. Photonic crystal structure is consisted of two dimensional (2D) air holes embedded in InP/InGaAsP material with an effective refractive index of 3.2634 which is arranged in a hexagonal lattice. The photonic band gap (PBG) of this structure is determined using the plane wave expansion (PWE) method by RSOFT Bandsolve software.  Band diagram also show an overlap of two photonic bandgaps for both TE and TM about 1.55 mm wavelength. Also, the band structure is calculated for a lattice constant of 625 nm and a radius of 266.6 nm. The proposed polarization splitter has a transmission spectral of 75% and 70% for the TE and TM polarized light, respectively. The proposed polarization splitter is realized in a standard semiconductor technology on InP substrate at 1.55 µm wavelength and can be easily monolithically integrated with other planar integrated circuits.