title: Coherent subterahertz radiation from femtosecond infrared filaments in air.
abstract: We report on what is believed to be the first observation of coherent subterahertz (sub-THz) emission from a 1-m string in the atmosphere. The sub-THz pulse emitted by the filamentary structure from an intense IR femtosecond laser pulse is detected perpendicularly to the laser propagation axis by use of two heterodyne detectors at 94+/-1 and 118+/-1GHz . We describe the characteristics of this emission and show evidence of constructive interference between two separate strings.
authors.forename: S
authors.initials: S
authors.lastname: Tzortzakis
authors.forename: G
authors.initials: G
authors.lastname: Méchain
authors.forename: G
authors.initials: G
authors.lastname: Patalano
authors.forename: Y-B
authors.initials: YB
authors.lastname: André
authors.forename: B
authors.initials: B
authors.lastname: Prade
authors.forename: M
authors.initials: M
authors.lastname: Franco
authors.forename: A
authors.initials: A
authors.lastname: Mysyrowicz
authors.forename: J-M
authors.initials: JM
authors.lastname: Munier
authors.forename: M
authors.initials: M
authors.lastname: Gheudin
authors.forename: G
authors.initials: G
authors.lastname: Beaudin
authors.forename: P
authors.initials: P
authors.lastname: Encrenaz