GaAs-based two-dimensional photonic crystal slab ring resonator consisting of a directional coupler and bent waveguides

Abstract

We experimentally demonstrated a GaAs-based air-bridge-type photonic crystal ring resonator that has a triangular lattice pattern of air holes. The fabricated photonic crystal ring resonator is composed of bent waveguides and an asymmetric directional coupler that has three rows of air holes between neighboring line-defect waveguides. We successfully demonstrated ring resonant spectral response in the fabricated devices and experimentally made clear the dependence of the oscillation period on the optical path length of the ring resonator and the dependence of ring resonant spectral response on the coupling properties of the directional coupler. In addition, we theoretically and experimentally discuss the group-velocity dispersion in the photonic crystal slab waveguide.