Room-temperature normal-mode coupling in a semiconductor microcavity utilizing native-oxide AlAl/GaAs mirrors

Abstract

A GaAs/AlAs microcavity containing six InGaAs quantum wells was grown, and the sample was then etched via chemically-assisted ion-beam etching to form 50-μm-diam cylindrical mesas. The formation of native oxides, accomplished by baking the samples at 400 °C in the presence of a pressurized N2/H2O vapor line, lowered the refractive index of the AlAs layers to 1.5. The higher refractive index contrast more effectively confined the intracavity field, leading to well-resolved reflectivity dips with an exciton-polariton splitting of 6.72 nm=9.44 meV at room temperature.