Abstract

It is well known that sharp excitonic resonances are observed in quantum wells, even at room temperature; however, it has been recently discovered that these sharp excitonic resonances can also exist in quantum wells in which the barriers are only a few tens of milli-electron- volts deep.¹ In such a case, the excitons retain some of the character of bulk material while exhibiting some of the interesting characteristics of the quantum well. Perpendicular electric fields applied to the shallow quantum wells have resulted in quantum-well modulators with high cw saturation intensity compared with "deep" quantum-well modulators, principally because the carrier confinement is significantly reduced.² In the present paper, we investigate the ultrafast nonlinear-optical properties and parallel field electroabsorption in this potentially important new material system.

© 1991 Optical Society of America