Fs-pulse propagation in presence of self-trapped excitons

The propagation of intense, ultrashort laser pulses in optical media is predominantly determined by the nonlinear pulse-matter interaction yielding pronounced NLO phenomena such as self-focussing or self-phase modulation. The electromagnetically induced nonlinear polarization originates from bound and/or (nearly) free carriers that are able to follow optical frequencies [1]. In this contribution we focus on the injection of self-trapped excitons (STE) by using intense fs laser pulses and their additional contribution to the nonlinear polarization.