FEMTOSECOND DYNAMICS OF THE OPTICAL STARK-EFFECT IN SEMICONDUCTOR-DOPED GLASS

We report the observation of the optical Stark shift in CdSxSe1-x semi conductor-doped glass excited under nonresonant below gap condition an d probed with femtosecond optical pulses. An ultrafast and pure light- induced shift of the bandedge is observed. The measured dependence of the band edge shift with the pump pulse peak intensity is linear for p ump intensities up to 0.3 GW/cm(2) Above this value, departure from li nearity is observed. For a pump intensity of 3 GW/cm(2), the band shif ts by 11 meV. The response of the shift tracks the profile of the pump ing pulse. (C) 1996 American Institute of Physics.