Amplitude and phase shaping in a high average power 1 kHz CPA-laser

Abstract

Summary form only given. Shaped, amplified fs-pulses have applications in the fields of coherent control of molecules and short pulse x-ray generation. For the generation of amplified shaped pulses with high average power, we utilized an acousto-optic shaping device named Dazzler (Fastlite). The acousto-optic wave in the crystal diffracts individual frequencies in the pulses with varying efficiencies, thus creating amplitude and phase modulated pulses. In our experiments, we temporally modify our pulses prior to the stretcher of a chirped pulse amplifier. We have been able to pre-compensate for higher order phase dispersion in the amplification process, which cannot be compensated by a compression grating. Using a feedback controlled adaptive algorithm, we show phase compensation results in a cleaner pulse than grating compression. For each case, we detuned the regenerative amplifier, by changing the number of round trips by one, which has the effect of adding dispersion. With phase-only shaping, phase information is kept through the amplification process, and can pre-compensate for phase distortion in a high peak power CPA-system.