Abstract

We have previously demonstrated picosecond all-optical switching in a waveguide directional coupler⁽¹⁾. It was shown that cross-well carrier sweep-out could be used to increase the recovery speed of the device by over an order of magnitude by employing a p-i-n doped structure⁽²⁾. In this work, we report time resolved measurements of optical nonlinearities in a waveguide structure containing a single GaAs quantum well which exhibits a fast recovery without the need for an applied electric field. We observe phenomena associated with exciton absorption quenching and screening of the internal field resulting in a dynamic shift of absorption edge by the quantum confined Stark effect.

© 1992 Optical Society of America