Retro-reflection of glass beads for traffic road stripe paints

The retro-reflection of light by glass beads injected in road stripes is studied experimentally and theoretically. The complete contribution of the retro-reflected intensity is modelled by taking into account the glass beads and the paint stripes. The efficiency of such a technique is evaluated for various compositions and densities of glass beads injected in paints, including the paint meniscus contributions. (c) 2007 Elsevier B.V. All rights reserved

Rayleigh and Raman scattering from helium for wavelengths down to 16 nm

We present results of calculations of Cross sections for Rayleigh (elastic) and Raman (inelastic) scattering of light from helium for wavelengths down to almost the threshold for double ionization. Our calculations were performed using a complex basis set expressed in perimetric coordinates. [S1050-2947(99)05504-3]

Two-color photoionization of helium above the N=2 ionization threshold

We study two-color photoionization of helium in the region of the 3s3d D-1 autoionizing state with resonant excitation of the intermediate 2s2p P-1 autoionizing state. We show that the corresponding time-dependent Schrodinger equation may be solved by expanding the total wave function on a few complex energy states. Perimetric coordinates are used to describe correlation effects accurately. Populations at the end of the interaction as well as photoionization probabilities are studied as a function of the laser pulse duration acid both frequencies. Our calculations show that many continua play a crucial role at high intensities. [S1050-2947(99)06308-8]

Global rainbow thermometry assessed by Airy and Lorenz-Mie theories and compared with phase Doppler anemometry

Global rainbow thermometry (GRT) measures the mean size and temperature of an ensemble of spray droplets. The domain of validity of the Airy theory for this technique is established through comparison with Lorenz-Mie theory. The temperature derivation from the inflection points of the Airy rainbow pattern appears to be independent of the type of spray dispersion. Measurements in a water spray are reported. The mean diameter obtained from the rainbow pattern lies between the arithmetic and the Sauter mean diameters measured by phase Doppler anemometry. The temperature measurement by GRT is shown to be accurate within a few degrees Celsius. (C) 2003 Optical Society of America

Ionization of H- by a strong ultrashort laser pulse

We compare the outcome of two different numerical methods aimed at solving the time-dependent Schrodinger equation associated with the interaction of H- with an ultrashort laser pulse. These methods of spectral and configuration interaction type are based on an expansion of the total wavefunction on eigenstates of H- built as products of either B-spline or complex Sturmian functions. A careful analysis of our results together with a comparison with other existing theoretical data sheds some light on subtle aspects of the theoretical treatments of H- in a strong laser field. A particular emphasis is put on the crucial role played by the density of states in the continua