Abstract

Degenerate four-wave mixing (DFWM) in GaAs/AlGaAs multiple quantum wells (MQWs) has been demonstrated in forward and backward configurations using pulsed lasers and with cw lasers in the forward configuration.^{1, 2} In bulk GaAs, DFWM has only been demonstrated at a low temperature with pulsed lasers.³ We report the first demonstration of cw backward DFWM in room temperature bulk GaAs and GaAs/AlGaAs MQW samples. The DFWM reflectivity is measured in the band gap region as a function of laser wavelength with intensity as a parameter. When the MQW samples are pumped at intensities sufficient to saturate the light and heavy hole excitonic resonances, a dispersive DFWM spectrum is observed, consistent with conduction band only contributions.⁴

© 1987 Optical Society of America