Abstract

The direct use of two-photon absorption in the below-bandgap region in a quantum well waveguide appears to be an attractive and simple method of obtaining all-optical modulation with relatively low (approaching Q- switched diode laser) power levels. Since ultrafast switching is often the key justification for using all-optical techniques, it is important to examine the conditions under which the direct use of nonlinear absorption allows ultra fast switching even when real charge carriers are excited. In this paper we present, for the first time, an experimental investigation of the bias and power dependence of all-optical modulation in a quantum well waveguide.

© 1993 Optical Society of America