Coherent subterahertz radiation from femtosecond infrared filaments in air

Stellios Tzortzakis (1) , Grégoire Méchain (1) , G. Patalano (1) , Yves-Bernard André (1) , Bernard Prade (1) , Michel A. Franco (1) , André Mysyrowicz (1) , J.-M. Munier (2) , M. Gheudin (2) , Gérard Beaudin (2) , Pierre Encrenaz (2)

1 LOA - Laboratoire d'optique appliquée
2 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique

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.

Keywords: filamentation; terahertz

Domains: Physics [physics]; Physics [physics]; Optics [physics.optics]

Stellios Tzortzakis, Grégoire Méchain, G. Patalano, Yves-Bernard André, Bernard Prade, et al.. Coherent subterahertz radiation from femtosecond infrared filaments in air. Optics Letters, 2002, 27 (21), pp.1944-1946. ⟨10.1364/OL.27.001944⟩. ⟨hal-00463674⟩