Heterostructure four channel wavelength demultiplexer using square photonic crystals ring resonators

We have designed a 4-channel wavelength division demultiplexer based on photonic crystal (PhC) ring resonator at 1.55 μm window. The PhC consists of pillars in air background in square lattice. The radius of the pillars is determined to be 126.5 nm having lattice constant of 590 nm. The proposed structure mechanism is performed based on coupling between a waveguide and a ring resonator. This structure is designed and its performance verified by finite difference time domain method. Dropping efficiency and quality factor (Q) of single ring are 100% and 193, respectively. Our proposed demultiplexer is composed of three regions with various dielectric constants of 11.56, 12.96, and 14.44. The proposed demultiplexer has efficiency about 90% and −25 dB crosstalk. The footprint of the proposed structure is about 315 μm2 (11.19 μm × 25.5 μm), therefore this structure suitable for integration.