Radiative coupling in single quantum wells and Bragg structures

Abstract

Time-integrated four-wave mixing experiments reveal strong influence of the cladding layer thickness d1, its refractive index and the reflectivity of the sample-air interface on the radiative dephasing time Trad of excitons in single quantum wells and multiple quantum well structures. A cladding layer thickness of λ/2 and λ/4 decreases and increases, respectively, Trad. Furthermore, we show that the superradiance is not limited to the heavy-hole exciton but can be observed even on excited and light-hole-exciton states as well as on correlated electron-hole-pair states. All findings agree fairly well with solutions of the semiconductor Maxwell-Bloch equations.