Influence of light holes on the heavy-hole excitonic optical Stark effect - art. no. 075323

Pump-probe experiments on high-quality InxGa1-xAs quantum wells are used to investigate the influence of light-hole excitons on the optical Stark effe ct. For anticircular polarization of pump and probe pulses and a moderate n egative detuning of the pump energy, a redshift of the heavy-hole resonance is observed. However, with increasingly negative detuning a transition fro m this redshift to a blueshift is found. Microscopic calculations that incl ude both heavy holes and light holes reproduce the experimental results. Th e theoretical analysis shows that the observation of the redshift depends v ery sensitively on the detuning of the pump pulses and the heavy-hole to li ght-hole splitting.