Realization of regular resonance mode in GaN-based polygonal microdisks on Si

Abstract

Regular resonance modes in GaN-based polygonal microdisks are investigated by simulations and photoluminescence measurements. Based on a standard GaN-based blue light emitting diode wafer on a Si substrate, hexagonal and octagonal microdisks with similar dimensions are fabricated. Whispering gallery-like modes and Fabry-Pérot modes in the polygonal microcavities are pictured by theoretical calculations. All resonant modes in the polygonal microdisks are confined along regular and isolated orbits. The resonant emission from the hexagonal and octagonal microdisks has been achieved at room temperature, which presents regular and ordered resonant emission peaks. The regularly varied mode spacing of the polygonal microdisks provides potential application in multiple-channel optic communication. The distinctive geometric structural features and mode characteristics make the polygonal microdisks greatly superior in terms of mode control and mode selection.