Photonic crystal ring resonator channel drop filter

Abstract

Photonic crystal channel drop filters (CDFs) with a ring resonator have been reported and have shown good optical properties to drop the light. Photonic crystal ring resonators (PCRRs) offer scalability in size and flexibility in mode design due to their multi-mode nature [1] compared to point-defect or line-defect photonic crystal (PhC) cavities. It is far smaller in size than other corresponding devices. In this paper, we proposed several channel drop filters combination of ring resonators and point defect micro-cavities. These ring resonators work as energy couplers. They capture the electromagnetic energy propagated in the input waveguide and send it to the output waveguide at its resonant frequencies. But ring resonators have too many resonant frequencies because of their multi-mode nature. So, point defect micro-cavities are used to further filter the original light wave. In our designed CDFs, close to 100% drop efficiency has been achieved at their center normalized frequencies, respectively.