Femtosecond Bloch vector control in quantum wells

Summary form only given.We report on a general approach to coherent control in semiconductors, based on optical waveforms with synthesized intensity and phase versus time. This technique is limited only by the bandwidth of the initial laser pulses and the spectral resolution of the pulse-shaping apparatus. It is therefore especially suitable to investigate effects such as off-resonant Rabi oscillations and polaritons in multiple quantum wells. Experiments were performed in four-wave mixing (FWM) and differential reflection geometry based on a mode-locked Ti:sapphire laser emitting 100-fs pulses.