Design and simulation of wavelength demultiplexer based on heterostructure photonic crystals ring resonators

In this paper, we have designed a four channel wavelength demultiplexer based on heterostructure photonic crystal (PhC) ring resonator at 1550 nm window. In order to achieve the structure of demultiplexer, three improved rings with different dielectric constants of 11.6, 12, and 12.4 have been used. Every ring has an individual dielectric constant; it means that each ring has a variable resonant wavelength. Quality factor (Q) and dropping efficiency of single ring are 842 and 100%, respectively. The results of simulation using finite difference time domain (FDTD) method shows this structure have a good performances and reveals an average transmitted power is higher than 95%, channel spacing is about 6.1 nm and bandwidth for each individual channel is about 2.75 nm. The mean value of the crosstalk between outputs channels and footprint of the proposed structure are about −24.44dB and 294.25 μm2 (10.7 μm×27.5 μm) respectively.