Photonic crystal higher order three-port channel drop filter

We present a photonic crystal (PC) three-port channel drop filter (CDF) with flat-top response and high quality factor value of 8836.7, and it can be used in the dense wavelength division multiplexing (DWDM) system. The CDF is engineered based on the three-port system with the wavelength-selective reflection feedback, where both micro-cavities are the synthesized coupled-resonators. In this case, the conditions to achieve complete power transfer are same to that of the corresponding three-port system while both micro-cavities are the single-mode resonators. As two micro-cavities are single point-defect resonators or synthesized coupled-resonators respectively, it is confirmed that these CDFs exhibit different response characteristics by the simulation results calculated by using two dimensional finite-difference time-domain (2D-FDTD) method, and these filters will find applications in future wavelength division multiplexing (WDM) optical communication systems.