Broad Tuning of Whispering-Gallery Modes in Microdisks

Abstract

Silicon microdisks with dynamically-tunable resonance spectra are achieved with narrow, in-plane silicon electrical contacts in a single lithographic step. Electrical current is passed through the devices to enable thermal tuning via joule heating. A 14nm wavelength shift is demonstrated with 1.6mW power consumption in devices with >20nm free spectral ranges and quality factors exceeding 20,000. Spectral shifts of several modal linewidths can be achieved with tuning powers below 100µW.