Coherent effects in resonant quantum well optical emission

The coherence of an excitonic ensemble resonantly excited by an ultrashort pulse is probed by arranging an interaction with a second identical pulse i n a time-resolved coherent control experiment. We demonstrate that the deca y of the amplitude of coherent control is faster than exciton dephasing for low excitation density. We also study the rise and the decay of the second ary emission from quantum well systems and observe how both of them show a dominant contribution of resonant Rayleigh scattering. (C) 1999 Elsevier Sc ience B.V. All rights reserved.