Optical lattices of InGaN quantum well excitons

Abstract

We demonstrate optical Bragg lattices formed by quasi-two-dimensional excitons in periodic systems of the InGaN quantum wells separated by the GaN barriers. When the Bragg resonance and exciton-polariton resonance are tuned to each-other, the medium exhibits an exciton-mediated resonantly enhanced optical Bragg reflection. The enhancement factor appeared to be larger than 2 for the system of 60 quantum wells. Owing to a high binding energy and oscillator strength of the excitons in InGaN quantum wells, the resonant enhancement was achieved at room temperature.