Ultra-Fast Stark-Induced Control of Polaritonic States
  A laser pulse, several meV red-detuned from the excitonic line of a quantum well, has been shown to induce an almost instantaneous and rigid shift of the lower and upper polariton branches. Here we demonstrate that through this shift, ultra-fast all-optical control of the polariton population in a semiconductor microcavity should be achievable. In the proposed setup a Stark field is used to bring the lower polariton branch in or out of resonance with a quasi-resonant continuous-wave laser, thereby favoring or inhibiting the injection of polaritons into the cavity. Moreover we show that this technique allows for the implementation of optical switches with extremely high repetition rates. 
Emiliano Cancellieri, Alex Hayat, Aephraim Steinberg, Elisabeth   Giacobino, Alberto Bramati
cond-mat.mes-hall cond-mat.other