Tunability of an Optical Filter Based on Photonic Crystal Ring Resonator

This paper investigated a channel drop filter based on a 2D photonic crystal structure. Two linear waveguides coupled through a square-shaped resonator were proposed in this design. The parameters which influence the output frequency of the filter were studied. The simulation results are obtained using the finite difference time domain (FDTD) method. By changing and combining the parameters of the device, the optimum results of the quality factor (Q) and the dropping efficiency are obtained. They attained, respectively, 1154 and 100%. The area of the suggested filter is about 167 µm2, which is suitable for optical integrated circuits (PICs).