LO-PHONON-MEDIATED OPTICAL STARK-EFFECT ENHANCED BY A QUASI-STATIC ELECTRIC-FIELD

A low-intensity electric field enhanced LO-phonon-mediated optical Sta rk effect (PMOSE) is proposed and studied theoretically for polar semi conductors (e.g., CdS). A large electrooptic nonlinearity responsible for this effect stems from a strong increase of the exciton-LO-phonon Frohlich interaction ill the presence of a quasi-static electric field . The PMOSE operates with a moderate electric field of 10(4) V/cm and optical intensities of approximate to 10 MW/cm(2). Both, the red and b lue effective shifts of the exciton line can be easily realized by cha nging the carrier frequency of the pump light. In order to calculate t he dynamical changes of excitonic reactivity we develop tile electrody namics of the PMOSE. Numerical modeling of the electric field enhanced PMOSE is given for excitons in CdS.