Adaptive shaping of femtosecond pulses

Summary form only given. We generalize the adaptive approach for pulse compression to adaptively shape completely uncharacterized femtosecond pulses into desired waveforms. In this approach, the input pulses are modified iteratively according to a feedback signal derived from a measurement of the output pulses. Consequently, the adaptive approach removes the need for characterization of the input pulses, and is applicable in cases where the pulses undergo slow variations in time. The experimental setup for adaptive pulse shaping uses a programmable 4-f pulse shaper, an intensity cross-correlation arrangement, and a computer. The computer was used for calculating the feedback signal, derived from the crosscorrelation measurement.