Signatures of carrier-wave Rabi flopping in GaAs -: art. no. 057401

For excitation of the model semiconductor GaAs with optical pulses which are both extremely short (5 fs) and extremely intense (approximate to 10(12) Wcm(-2)), we can meet the condition that the Rabi frequency becomes comparable to the band gap frequency-a highly unusual and previously inaccessible situation. Specifically, in this regime, we observe carrier-wave Rabi flopping, a novel effect of nonlinear optics which has been predicted theoretically and which is related to the failure of the area theorem.