title: Enhanced spatiotemporal laser-beam smoothing in gas-jet plasmas.
abstract: Spatiotemporal smoothing of large-scale laser intensity fluctuations is observed for a laser beam focused into underdense helium plasmas. This smoothing is found to be severely enhanced when focusing the laser beam into a helium gas jet. In contrast to other experiments with preformed plasmas, the average and the peak laser intensities are well below the threshold for ponderomotive self-focusing. The coherence characteristics of the transmitted light are measured for various electron densities, and the smoothing effect is explained by multiple scattering of laser light on self-induced density perturbations.
authors.affiliation: Laboratoire d'Optique Appliquée, Ecole Nationale Supérieure des Techniques Avancées, Centre de la Recherche Scientifique UMR 7639, 91761 Palaiseau, France.
authors.forename: V
authors.initials: V
authors.lastname: Malka
authors.forename: J
authors.initials: J
authors.lastname: Faure
authors.forename: S
authors.initials: S
authors.lastname: Hüller
authors.forename: V T
authors.initials: VT
authors.lastname: Tikhonchuk
authors.forename: S
authors.initials: S
authors.lastname: Weber
authors.forename: F
authors.initials: F
authors.lastname: Amiranoff