Optical stark effect of excitons in semiconductors

Abstract

The optical Stark effect is demonstrated in Cu 2O and multiple-quantum-well structures. In Cu 2O the 2P and 1S excitons are dynamically coupled by a strong laser field (CO 2 laser). The induced change of transmission and its polarization dependence can be quantitatively described in terms of the nonlinear susceptibility χ NL. In a similar experiment the dynamical coupling between the n=1 and n=2 conduction band sublevels is measured in a GaAs-AlGaAs multiple-quantum-well structure (MQWS). This coupling depends critically on the polarization of the high-power CO 2 laser, since the transition from the n=1 to the n=2 sublevel is allowed only for a polarization perpendicular to the layers.