title: Efficient third-harmonic generation through tailored IR femtosecond laser pulse filamentation in air.
abstract: The process of third-harmonic generation during the filamentation of intense IR femtosecond laser pulses in air is investigated experimentally. It is shown that the introduction of a thin plasma string created by another femtosecond pulse, perpendicularly to the filament's path, dramatically reshapes the third-harmonic beam into a Bessel-like far-field distribution, while at the same time significantly enhances, up to 250 times, its conversion efficiency.
authors.affiliation: Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110, Heraklion, Greece. ssuntsov@iesl.forth.gr
authors.forename: S
authors.initials: S
authors.lastname: Suntsov
authors.forename: D
authors.initials: D
authors.lastname: Abdollahpour
authors.forename: D G
authors.initials: DG
authors.lastname: Papazoglou
authors.forename: S
authors.initials: S
authors.lastname: Tzortzakis