SHORT-PULSE AMPLIFICATION IN AN F2 GAIN MODULE

We report on what is to our knowledge the first subpicosecond-pulse am plification experiments in an F2 gain module at 157 nm. 500-fs seed pu lses were produced by a four-wave mixing process in xenon by excitatio n with KrF short-pulse radiation. The amplification experiments yield a small-signal gain coefficient of approximately-5%/cm and an estimate for the saturation energy density of approximately 180 muJ/cm2. For a single-pass amplification, an output energy of 60 muJ has been measur ed so far. From the spectral width of the amplification spectra, a min imum possible duration of approximately 200 fs for the amplification o f short pulses can be estimated.