Supercontinuum emission and enhanced self-guiding of infrared femtosecond filaments sustained by third-harmonic generation in air

Journal Article · Sat Jan 01 00:00:00 EST 2005 · Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics

DOI:https://doi.org/10.1103/PhysRevE.71.016602· OSTI ID:20641362

Berge, L ^[1]; Skupin, S ^[1]; Mejean, G; Kasparian, J; Yu, J; Frey, S; Salmon, E; Wolf, J P ^[2]

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1. Departement de Physique Theorique et Appliquee, CEA/DAM Ile de France, Boite Postale 12, 91680 Bruyeres-le-Chatel (France)
2. Laboratoire de Spectrometrie Ionique et Moleculaire, Universite Claude Bernard Lyon 1, UMR-CNRS 5579, F-69622 Villeurbanne cedex, Lyon (France)

The long-range propagation of two-colored femtosecond filaments produced by an infrared (IR) ultrashort pulse exciting third harmonics (TH) in the atmosphere is investigated, both theoretically and experimentally. First, it is shown that the coupling between the pump and TH components is responsible for a wide spectral broadening, extending from ultraviolet (UV) wavelengths (220 nm) to the mid-IR (4.5 {mu}m). Supercontinuum generation takes place continuously as the laser beam propagates, while TH emission occurs with a conversion efficiency as high as 0.5%. Second, the TH pulse is proven to stabilize the IR filament like a saturable quintic nonlinearity through four-wave mixing and cross-phase modulation. Third, the filamentation is accompanied by a conical emission of the beam, which becomes enlarged at UV wavelengths. These properties are revealed by numerical simulations and direct experimental observations performed from the Teramobile laser facility.

• OSTI ID: 20641362
• Journal Information: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, Vol. 71, Issue 1; Other Information: DOI: 10.1103/PhysRevE.71.016602; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-651X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AIR
ATMOSPHERES
CONVERSION
EFFICIENCY
FILAMENTS
HARMONIC GENERATION
HARMONICS
INFRARED SPECTRA
LASERS
LIGHT TRANSMISSION
LINE BROADENING
MODULATION
NONLINEAR PROBLEMS
PULSES
SIMULATION
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA
VELOCITY
VISIBLE SPECTRA
WAVELENGTHS