Heating of conduction band electrons by intense femtosecond laser pulsesA. Belsky1, 2, P. Martin1, H. Bachau1, A. N. Vasil'ev2, B. N. Yatsenko1, 2, S. Guizard3, G. Geoffroy3 and G. Petite3
1 Centre des Lasers Intenses et Applications, UMR5107 CNRS-Université de Bordeaux I-CEA, Université de Bordeaux I - 33405 Talence Cedex, France
2 Physics Faculty, Moscow State University - Moscow 119992, Russia
3 Laboratoire des Solides Irradiés, UMR7642, CEA/DSM/DRECAM-CNRS Ecole Polytechnique - 91128 Palaiseau Cedex, France
(Received 11 February 2004; accepted in final form 10 May 2004)
We present photoelectron spectra for excited by intense femtosecond -Sapphire laser pulses. A high-energy plateau is detected in the spectra, at excitation intensities above 0.5 . This plateau extends up to 24 at 3 and 90% of the emitted electrons have energy higher than twice the laser photon energy. Such intensive electron heating in solids cannot be explained in terms of phonon-assisted transitions. A model of direct interbranch transitions in the conduction band is used for the simulation of the heating process.
79.20.Ds - Laser-beam impact phenomena.
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