Reflected degenerate four-wave mixing on GaAs single quantum wells

Abstract

Time-resolved degenerate four-wave mixing (DFWM) on two-dimensional (2D) excitons in GaAs single quantum wells is studied. We observe backward coherent emission (DFWM signal) from the 2D excitons comparable in efficiency to that in forward direction. This reflection or backward DFWM configuration is extremely advantageous and useful in exploring optically thin semiconductor layers.