title: Phase modulation of intense ultrashort laser pulses reflected from steep, dense plasmas.
abstract: The phase modulation of intense ( I = 10(18) W/cm(2)) ultrashort laser pulses ( tau(p) = 70 fs) after reflection from steep, dense plasmas has been temporally resolved for the first time in particle-in-cell simulations. The position of the turning point from where the pulse reflects has been compared to the phase modulation, over a range of angles of incidence. At normal incidence or s polarization the phase modulation almost exactly represents the movement of the turning point due to the light pressure. As the angle of incidence is increased for p polarization, the simple Fresnel relationship between phase modulation and displacement of the reflection position, Delta phi(t) = -2k(0)Delta x(t)cos theta(0), increasingly breaks down.
authors.affiliation: Insitut für Optik und Quantenelektronik, Friedrich-Schiller Universität, Jena, Germany.
authors.forename: R J
authors.initials: RJ
authors.lastname: Kingham
authors.forename: P
authors.initials: P
authors.lastname: Gibbon
authors.forename: W
authors.initials: W
authors.lastname: Theobald
authors.forename: L
authors.initials: L
authors.lastname: Veisz
authors.forename: R
authors.initials: R
authors.lastname: Sauerbrey