Efficient generation of subpicosecond seed pulses at 193 nm for amplification in ArF gain modules by frequency mixing in nonlinear optical crystals

Generation of high-power subpicosecond pulses at 155 nm

Subpicosecond vacuum-ultraviolet radiation at 155 nm with pulse energies above 0.2 mJ has been obtained by near-resonant four-wave difference-frequency mixing in a Xe gas jet. Laser fields for the mixing process have been generated by a short-pulse KrF dye excimer laser system and a Raman converter. The process permits tuning in a broad vacuum-ultraviolet range and can be scaled up to higher output energies.

Intensity-dependent transmission properties of window materials at 193-nm irradiation

We measured the transmission of MgF(2), CaF(2), BaF(2), and fused-silica window materials, using 0.8-ps optical pulses at 193 nm with intensities from 1 to 300 GW/cm(2). The two-photon absorption coefficients beta are extracted from these measurements. The excited excitonic fluorescence in CaF(2) and BaF(2) shows a quadratic dependence on the irradiation intensity in a wide range.

Measurement of ultraviolet subpicosecond pulses based on ultrafast beam deflection

We describe a beam-deflection technique based on the ultrafast electronic Kerr effect for measuring the duration of ultrashort laser pulses in a wide spectral range. Using this method, which provides the third-order intensity correlation function, we have measured subpicosecond KrF laser pulses. The results are in good agreement with the Kerr-shutter autocorrelation measurement.

High-repetition-rate high-power femtosecond ArF laser source

170-fs, 0.8-microJ optical pulses at 193 nm generated by frequency quadrupling of high-power Ti:sapphire laser pulses are amplified in an ArF gain module. Double-pass amplification at a 400-Hz repetition rate resulted in 290-mW average power with pulse durations of ~ 300 fs.

Short-pulse amplification and gain dynamics of an ArF excimer amplifier

Subpicosecond pulses at 193 nm, generated by a nonresonant difference-frequency mixing process in xenon, have been amplified in an ArF excimer gain module to output energies of as much as 10 mJ. Investigations on the gain characteristics of the ArF excimer amplifier yield a saturation energy density of 1.9 mJ/cm(2) and a maximum small-signal gain coefficient of 0.15 cm(-1). Gain recovery measurements have been performed. A dominant gain recovery time of ~3 ns with indications of a small fast contribution in the picosecond range have been observed.