GaN microcavities and Bragg reflectors: giant exciton–light coupling

Numerical simulation of light reflection from a λ/2 GaN microcavity with Ga0.8Al0.2N/Ga0.5Al0.5N Bragg mirrors grown on the A-surface of Al2O3 revealed a Rabi-splitting of the order of 50 meV and remarkable optical anisotropy. In a separate Bragg mirror, the exciton interference results in a 95% modulation of reflection spectra. These effects originate from the giant exciton oscillator strength in GaN and a pronounced uniaxial strain in the structure.