S. Varro et F. Ehlotzky, THE MULTIPHOTON PHOTO-EFFECT AND HARMONIC-GENERATION AT METAL-SURFACES, Journal of physics. D, Applied physics, 30(22), 1997, pp. 3071-3078
By using a dipole-layer model for the scattering of electrons at a met
al surface in a laser field, we show that, at relatively moderate lase
r intensities of some 10(10) W cm(-2) of a Nd:YAG laser, photo-electro
ns of very high nonlinear order are generated having energies of up to
about 500 eV. Similarly, we predict harmonics of very high order unde
r the same parameter conditions. The high-order electron-energy spectr
um agrees very well with recent observations by Parkas et al (Phys. Re
v. A 41 4123 (1990); Opt Eng. 32 2476 (1993)). With our model predicti
ons one does not need to resort to the mechanism of Coulomb explosion
in order to explain the observed high-energy photo-electrons.