High-brightness subpicosecond terawatt KrF* system driven with a frequency-converted self-mode-locked pulse-compressed Ti:Al_2O_3 laser

The phase control achievable in a subpicosecond self-mode-locked pulse-compressed Ti:Al2O3 system permits the production of a seed beam for a KrF* (248-nm) system operating near the power limit determined by self-phase modulation in the optical window material used. These limits are ~14 and ~30 GW/cm2 for CaF2 and MgF2 optics, respectively. We show experimental results for CaF2, which at 248 nm demonstrate a pulse length of ~270 fs, a pulse energy of ~240 mJ, and a resulting brightness of ~2.9 × 1021 W cm−2 sr−1.