Architecture of a blue high contrast multiterawatt ultrashort laser

The strategy used to develop an innovative high contrast multiterawatt femtosecond laser chain based on a hybrid (solid/gas) technology is reported. The laser system includes a Ti:sapphire oscillator generating 50 fs pulses at 950 nm, an optical parametric chirped pulse amplification stage, a second harmonic frequency converter for pulse temporal cleaning, and a final photolytical XeF(C--A) excimer amplifier for direct high peak-power amplification of ultrashort laser pulses in the blue (475 nm) spectral region. Several important issues concerning the design of the laser front-end, the energy extraction and beam phase control in the high peak-power XeF(C--A) amplifier are theoretically addressed. A detailed description of the XeF(C--A) amplifier and careful measurements of its energetic, optical and pumping characteristics are also given, together with the first pilot amplification experiments in the low density XeF(C--A) medium to assert the significance of our approach.