Computing of the quality factor in a two dimensional photonic crystal microcavity

In the present paper, we present the design of a filter formed by two waveguide couplers and one microcavity in a photonic crystal (PC) with a square lattice consists of long cylinders of silicon (Si) rods. Waveguide 1 and waveguide 2 are obtained by removing one row of rods. They are used to couple light in and out the microcavity. The finite difference time domain (FDTD) method (fullwave simulator) has been used to simulate optical propagation in this filter. Two rods have been located in the input and output channel waveguides. Their numbers and size have been varied in order to optimize the transmitted power and quality factor of the microcavity. We demonstrate that the calculated Q factor for the designed cavity increases with displacing rods, while the calculated modal volume remains almost constant.