2D-Heterostructure Photonic Crystal Formation for On-Chip Polarization Division Multiplexing

Herein, we offer a numerical study on the devising of a unique 2D-heterostructure photonic crystal (PC) that can split two orthogonally polarized light waves. The analysis is performed via a two-dimensional finite element method (2D-FEM) by utilizing the COMSOL Multiphysics software. The device consists of two discrete designs of PC formation. The first PC formation is optimized so that it permits both TE- and TM-polarization of light to transmit through it. Whereas, the second PC formation possesses a photonic bandgap (PBG) only for TE-polarized light. These two formations are combined at an angle of 45°, resulting in a reflection of self-collimated TE-polarized light at an angle of 90° owing to the PBG present in the second PC formation. While permitting the self-collimated TM-polarized light wave to travel uninterrupted. The proposed device has a small footprint of ~10.9 μm2 offering low transmission loss and high polarization extinction ratio which makes it an ideal candidate to be employed as an on-chip polarization division multiplexing system.