Efficient chirped-matched third harmonic generation of long UV pulses

In this paper, the authors demonstrate a technique to generate efficient broadband UV pulses at 263.5 nm from 20-40 ps chirped pulses at 790 nm through second harmonic (SHG) and sum frequency (SFG) generations in two type-I BBO crystals. By matching adequately the chirps of the second harmonic and fundamental pulses, up to 275 muJ of UV light could be generated from a ~10 mJ, 50 nm-bandwidth, 10 Hz-CPA Ti:Sapphire laser system, despite the involved pulses durations.