title: Plasma formation dynamics within a water microdroplet on femtosecond time scales.
abstract: We demonstrate that a highly confined plasma inclusion is formed inside a micrometric water droplet that is excited by a femtosecond laser. An 800-nm laser pulse generates a plasma inclusion by laser-induced breakdown that is subsequently probed by the elastic scattering of a second (400-nm) time-delayed ultrashort pulse. For a 25-microm-radius droplet and an incident intensity of 7 x 10(12) W/cm2 the radius of the highly localized plasma is 1.9 +/- 0.4 microm. We probed the plasma formation dynamics on femtosecond time scales by varying the delay between the pump and the probe pulses. Good agreement with numerical simulations of the process was found.
authors.affiliation: Laboratoire de Spectrométrie Ionique et Moléculaire (LASIM) (Unité Mixte de Recherche 5579), Université Claude Bernard Lyon 1, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France.
authors.forename: François
authors.initials: F
authors.lastname: Courvoisier
authors.forename: Véronique
authors.initials: V
authors.lastname: Boutou
authors.forename: Catherine
authors.initials: C
authors.lastname: Favre
authors.forename: Steven C
authors.initials: SC
authors.lastname: Hill
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Wolf