Functional optical filters based on two-dimensional photonic crystals

Abstract

We propose three types of optical filters composed of point and line defects in two-dimensional photonic crystals, bent filters, directional filters, and multi-channel drop filters. The filtering is performed by using the coupling between the cavity modes of the point defects and the guiding modes of the line defects. The filtered frequency can be tuned to the desired frequency by designing the geometries of the point defects. The filtering position and direction are also controlled by choosing the positions of the point defects and the directions of line defects. The proposed filters could be useful in miniature photonic integrated circuits.