Design of Six Channel Demultiplexer by Heterostructure Photonic Crystal Resonant Cavity

ABSTRACT: We have proposed a six channel demultiplexer based on a Heterostructure photonic crystal (PhC) resonant cavity. In order to achieve the structure of demultiplexer, six improved cavities with different refractive indexes of 3.50, 3.48, 3.46, 3.44, 3.42 and 3.40 have been used. Each cavity has an individual refractive index; it means that each cavity has a varying resonant frequency. Simulation results using finite-difference time-domain (FDTD) method reveals that in our proposed structure an average transmitted power higher than 95.5%, channel spacing is about 12.5×10-4 c/a, mean value of quality factor (Q) is 2319 and bandwidth for each individual channel is about 18×10-5 c/a. The mean value of the crosstalk between outputs channels is about -29dB. By changing the refractive index, various frequencies can be chosen; therefore this structure is able to dropping desired frequencies.