Absolute phase control of amplified femtosecond pulses

Spectral phase modulation has been recognized as a powerful mean of generating arbitrary shaped waveforms in the temporal domain ([1], [2]) and of correcting spectral defects of Chirped Pulse Amplification systems ([3]), but results were always characterized by indirect means. We demonstrate here, for the first time to our knowledge, full phase control in an amplified system with arbitrary phase patterns using an absolute phase measurement at the output of the laser chain and a phase modulator at the input of the amplifier.