title: Generation of 12 fs deep-ultraviolet pulses by four-wave mixing through filamentation in neon gas.
abstract: Generation of deep-ultraviolet femtosecond pulses by four-wave mixing through filamentation in neon gas was demonstrated. Fundamental (omega) and second-harmonic (2omega) pulses of 25 fs Ti:sapphire amplifier output were focused into neon gas, and 20 microJ pulses with the center wavelength of 260 nm were produced by a four-wave mixing process, 2omega+2omega-omega?3omega through an ~15 cm filament. Additionally, pulses with an energy of 2 microJ at 200 nm were generated, probably by a cascaded process, 3omega+2omega-omega?4omega. The 260 nm pulses were compressed by a grating-based compressor and characterized by a dispersion-free transient grating frequency-resolved optical gating. The estimated pulse width was 12 fs.
authors.affiliation: Chemical Dynamics Laboratory, RIKEN, Hirosawa 2-1, Wako, Saitama, 351-0198, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Fuji
authors.forename: Takuya
authors.initials: T
authors.lastname: Horio
authors.forename: Toshinori
authors.initials: T
authors.lastname: Suzuki