The multiphoton photo-effect and harmonic generation at metal surfaces

Abstract

Abstract. By using a dipole-layer model for the scattering of electrons at a metal surface in a laser field, we show that, at relatively moderate laser intensities of some 10 10 W cm −2 of a Nd:YAG laser, photo-electrons of very high nonlinear order are generated having energies of up to about 500 eV. Similarly, we predict harmonics of very high order under the same parameter conditions. The high-order electron-energy spectrum agrees very well with recent observations by Farkas et al (Phys. Rev. A 41 4123 (1990); Opt. Eng. 32 2476(1993). With our model predictions one does not need to resort to the mechanism of Coulomb explosion in order to explain the observed high-energy photo-electrons.

Nonlinear photoelectron emission from metal surfaces induced by short laser pulses: the effects of field enhancement by surface plasmons

“…The experimental results for lower laser intensities are reflected back reasonably well in our theoretical calculations, both in the lowenegy and in the high-energy part of the spectra. On the basis of these investigation we conclude that both our experimental and theoretical results support the physical picture offered by our concept of plasmon-induced oscillating near field (see [14][15][16], [7] and [17]) of a double layer at the metal-vacuum interface.…”

“…The time-averaged outgoing electron current components for which the momenta , which relation must hold for arbitrary instants of time. The resulting two coupled infinite set of linear algebraic equations for n R and n T can be numerically solved without any particular difficulty, moreover in our earlier works [14][15][16] we have derived quite accurate analytic approximate formulas, too. According to these resuts, the current components normalized to the incoming current can be expressed as…”

“…As we have seen before, in the frame of the standard nonperturbative Volkov description there is no chance to interpret this experiment, and several earlier experiments (as has also been emphasized in Refs. [14][15][16], [7] and [17]). The theoretical results are summarized in Fig.…”

Anomalous photoemission from Ag(100) in the femtosecond regime

“…Some speculative scenarios will be also mentioned, legitimated in so doing by the diffi-culty to find a convincing explanation within more conventional processes. Finally, we notice that the above features of nonlinear photoemission could be exploited to produce a bursts of energetic electrons 19,20 and that, in addition to more fundamental motivations, the study of hot electrons at metal surfaces and the efforts to clarify the physical mechanism responsible for them can be of relevance in the field of photocatalysis.…”

Quantum mechanical scattering by time-periodic potentials

“…We also note that the nonrelativistic version of a similar problem has been considered in Refs. [113,114] in the context of multiphoton ionization. Besides its relevance to graphene with a band gap, this work may also contribute to the manipulation of relativistic charged particle beams by powerful laser pulses [115][116][117].…”