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Palaiseau, France

Lalousis P.,Institute of Electronic Structure and Laser FORTH | Hora H.,University of New South Wales | Eliezer S.,Polytechnic University of Mozambique | Martinez-Val J.-M.,Polytechnic University of Mozambique | And 3 more authors.
Physics Letters, Section A: General, Atomic and Solid State Physics

Ignition of nuclear fusion flames in solid state density fuel following Chu's model of 1972 is evaluated using now available plasma blocks from ultrahigh acceleration with laser pulses of picosecond (ps) duration and power up to and beyond petawatt (PW). A new numerical approach is reported where genuine two-fluid hydrodynamics is used in order to study the shock mechanism of the generated fusion flame, its propagation velocities above 1000 km/s, and fusion efficiencies for deuterium-tritium needing an energy flux of 10 8 J/cm2. The results of the built-up of the shock process are reported showing a basic difference between the ps and nanosecond (ns) properties. © 2013 Elsevier B.V. Source

Giambruno F.,Ecole Polytechnique - Palaiseau | Freneaux A.,Ecole Polytechnique - Palaiseau | Cheriaux G.,Laboratoire DOptique Appliquee
Applied Physics B: Lasers and Optics

A multilayer mirror for spectral filtering adapted to ultra-short and multi-PW Ti:Sa laser has been designed, manufactured and characterized. The method used to determine both the reflectivity shape and the coating design leads to global compensation of gain narrowing, saturation and spectral phase. The result is a spectral control on 200 nm range while keeping a flat spectral phase. This kind of filter will enable obtaining 15 fs pulse duration for multi-PW laser systems based on Ti:Sa. © 2013 Springer-Verlag Berlin Heidelberg. Source

Marchenko T.,FOM Institute for Atomic and Molecular Physics | Marchenko T.,Laboratoire DOptique Appliquee | Marchenko T.,CNRS Laboratory of Physical Chemistry - Matter and Radiation | Muller H.G.,FOM Institute for Atomic and Molecular Physics | And 3 more authors.
Journal of Physics B: Atomic, Molecular and Optical Physics

We present angle- and energy-resolved measurements of photoelectrons produced in strong-field ionization of Xe using a tunable femtosecond laser. An occurrence of highly oscillatory patterns in the angular distribution at low photoelectron kinetic energy is observed that correlates with channel closing/opening over a wide range of laser parameters. The correlation is investigated both experimentally and by means of systematic analysis of numerical solutions of the time-dependent Schrödinger equation. Our experimental and numerical results are in quantitative agreement with the semi-classical model introduced by Arbó et al (2008 Phys. Rev. A 78 013406), which relates the oscillatory patterns to interference between photoelectrons produced during different cycles of the laser pulse in the course of non-resonant ionization of the atom. We observe that an increase of the laser intensity eventually leads to qualitative invariance of the pattern, defining a limit on the applicability of the semi-classical model. © 2010 IOP Publishing Ltd. Source

Bayleyegn M.D.,University Paris - Sud | Makhlouf H.,University Paris - Sud | Crotti C.,Laboratoire DOptique Appliquee | Plamann K.,Laboratoire DOptique Appliquee | Dubois A.,University Paris - Sud
Optics Communications

We present an ultrahigh resolution spectral-domain optical coherence tomography imaging system using a broadband superluminescent diode light source emitting at a center wavelength of 1.3 μm. The light source consists of two spectrally shifted superluminescent diodes that are coupled together into a single mode fiber. The effective emission power spectrum has a full width at half maximum of 200 nm and the source output power is 10 mW. The imaging system has an axial resolution of 3.9 μm in air (<3.0 μm in biological tissue), and a lateral resolution of 6.5 μm. The sensitivity and the maximum line rate are 95 dB and 46 kHz, respectively. Images of an infrared viewing card and a cornea from human eye suffering from glaucoma showing Schlemm's canal are presented to illustrate the performance of the system. © 2012 Elsevier B.V. All rights reserved. Source

Joshi C.,University of California at Los Angeles | Malka V.,Laboratoire DOptique Appliquee
New Journal of Physics

The ability of short but intense laser pulses to generate high-energy electrons and ions from gaseous and solid targets has been well known since the early days of the laser fusion program. However, during the past decade there has been an explosion of experimental and theoretical activity in this area of laser-matter interaction, driven by the prospect of realizing table-top plasma accelerators for research, medical and industrial uses, and also relatively small and inexpensive plasma accelerators for high-energy physics at the frontier of particle physics. In this focus issue on laser- and beam-driven plasma accelerators, the latest advances in this field are described. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Source

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