Europhys. Lett.
Volume 67, Number 2, July 2004
Page(s) 301 - 306
Section Interdisciplinary physics and related areas of science and technology
Published online 01 July 2004
Europhys. Lett., 67 (2) , pp. 301-306 (2004)
DOI: 10.1209/epl/i2004-10058-0

Heating of conduction band electrons by intense femtosecond laser pulses

A. 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 $\chem{CsI}$ excited by intense femtosecond $\chem{Ti}$-Sapphire laser pulses. A high-energy plateau is detected in the spectra, at excitation intensities above 0.5 $\un{TW/cm^2}$. This plateau extends up to 24 $\un{eV}$ at 3 $\un{TW/cm^2}$ 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.

© EDP Sciences 2004