Microcavities in Channel Waveguides

Abstract

We introduce and analyse a new type of resonant microcavity consisting of a channel waveguide and a one-dimensional photonic crystal. A band gap for the guided modes is opened and a state is created within the gap by adding a single defect in the periodic system. An analysis of the eigenstates in the system shows that a strong field confinement of the defect state can be achieved with a modal volume less than half of a cubic half-wavelength. The coupling efficiency to this mode will be shown to exceed 80%. As a proof of concept, we present a feasibility study for the fabrication of these microcavities in an air-bridge configuration with micron-sized features using semiconductor materials.