Comparison of semiconductor microcavity with ring and disk resonators

Abstract

In recently years, high-index-contrast semiconductor ring and disk resonators have attracted much attention.Nanofabrication techniques now allow the realization of semiconductor microcavity ring and disk resonators with evanescent wave coupling to submicron-width waveguides across submicron-width air gaps. In this paper, we use the finite-difference time-domain (FDTD) method to simulate the coupling efficiencies and resonant frequencies for optical microcavity ring and disk resonators devices. Studies of the transmission characteristics illustrate the transition from single-mode resonances to whispering-gallery-mode resonances as the waveguide width of the micro-ring approaching to a fulfilled micro-disk.