Quantum Optoelectronics

Abstract:

We study the ultrafast properties of secondary radiation of semiconductor quantum wells under resonant excitation. We show that the exciton density dependence allows one to identify the origin of secondary radiation. At high exciton densities, the emission is due to incoherent luminescence with a rise time determined by exciton-exciton scattering. For low densities, when the distance between excitons is much larger than their diameter, the temporal shape is independent of density and rises quadratically, in excellent agreement with recent theories for resonant Rayleigh scattering. © 1997 The American Physical Society.

Abstract:

Luminescence has been quite widely used for the study of semiconductor nanostructures, and more especially time resolved luminescence, due to the ease to get a luminescence signal. The interpretation of the results however is sometimes quite complex, and one generally finds that some care has to be taken for the results to be meaningful. In particular, the homogeneity of the excited density over the detected luminescence signal is a quite important parameter, also it is often desirable to work at the lowest possible densities.