Abstract

Irradiation of a medium with non-resonant light leads to a shift of the energy levels in the system. This optical, or dynamical Stark effect has been studied for many years in atomic gases. It is only recently, however, that it could be detected for excitonic transitions in solids. This development has stirred considerable interest, because the optical Stark effect has inherent features which makes it well suited for applications such as in ultrafast all-optical data processing. Since the pump light beam falls in a transparency region of the medium, it experiences little loss, in contrast to optical non-linearities based on a saturation mechanism. Also, because virtual transitions are involved, the light-induced shift of exciton levels follows closely the pump pulse duration, making it possible to design ultrafast all-optical logic gates with subpicosecond switch-on and -off times.

© 1988 Optical Society of America