Design of Optical Band Pass Filter Based on Photonic Crystal with Resonance Cavity

Recently, regarding the performance of photonic crystal band-pass filters in optical networks connection, optical integrated circuits, and short wavelength with high frequency, has attracted a lot of attention. In this paper, Our goal is designing a new type of photonic crystal band-pass filters using a waveguide cavity in the form of reduction in size of the cell, that as a result we create a filter in the function of the urban wavelength with an acceptable bandwidth. Here, two types of filters have been used and optimized that the operation has been conducted by Rsoft software and FDTD two-dimensional technique. The first method is the reduction of the size of cells in waveguide and elimination of some cells in the same direction. The second method is the elimination of two cells in the vicinity of waveguide in the center of the structure. Numerical results show that the light in a band around 1.550 um passes through with maximum value. The efficiency has increased more than the previous structures, it is about 80%.