title: Infrared generation by filamentation in air of a spectrally shaped laser beam.
abstract: We demonstrated the generation of infrared radiation by filamentation of a spectrally shaped femtosecond laser beam. The spectrum is divided in two distinctive parts using an acousto-optic programmable dispersive filter (AOPDF) as a pulse shaper, resulting in two pulses of different colors. One pulse is frequency doubled and the beams are then focused to produce an optical filament. Efficient infrared generation occurred in the filament zone through the four-wave mixing interaction. This in-line setup allowed perfect spatial overlap of the pulses, fine control of the relative delay and the remote control of the infrared spectral distribution through spectral shaping of the initial femtosecond laser beam via the AOPDF.
authors.affiliation: Institut National de la Recherche Scientifique Énergie, Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Québec J3X 1S2, Canada. lassonde@emt.inrs.ca
authors.forename: P
authors.initials: P
authors.lastname: Lassonde
authors.forename: F
authors.initials: F
authors.lastname: Théberge
authors.forename: S
authors.initials: S
authors.lastname: Payeur
authors.forename: M
authors.initials: M
authors.lastname: Châteauneuf
authors.forename: J
authors.initials: J
authors.lastname: Dubois
authors.forename: J-C
authors.initials: JC
authors.lastname: Kieffer