Generation of input signals for ArF amplifiers

Four different schemes for the generation of femtosecond input pulses for ArF amplifiers are described. Pulse energies of 100 nJ were obtained with phase-matched frequency mixing of a Raman-shifted frequency-doubled pulse derived from a 537-nm femtosecond dye-laser pulse. Excellent spatial, spectral, and amplitude stability was obtained when a broadband, nanosecond dye laser at 690 nm was used as a Raman seed pulse. Preliminary amplification experiments resulted in 0.5-mJ ArF output pulses of 340 fsec.