Ion acceleration driven by superintense laser pulses is attracting an impressive and steadily increasing\ud effort. Motivations can be found in the applicative potential and in the perspective to investigate novel regimes as available laser intensitieswill be increasing. Experiments have demonstrated, over a wide range\ud of laser and target parameters, the generation of multi-MeV proton and ion beams with unique properties\ud suchas ultrashort duration, high brilliance, and low emittance. An overview is given of the state of the art of\ud ion acceleration by laser pulses aswell as an outlook on its future development and perspectives.The main\ud features observed in the experiments, the observed scaling with laser and plasma parameters, and the main\ud models used both to interpret experimental data and to suggest new research directions are described

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The generation of energetic electron bunches by the interaction of a short, ultraintense (I>10(19)  W/cm(2)) laser pulse with "grating" targets has been investigated in a regime of ultrahigh pulse-to-prepulse contrast (10(12)). For incidence angles close to the resonant condition for surface plasmon excitation, a strong electron emission was observed within a narrow cone along the target surface, with energy spectra peaking at 5-8 MeV and total charge of ∼100  pC. Both the energy and the number of emitted electrons were strongly enhanced with respect to simple flat targets. The experimental data are closely reproduced by three-dimensional particle-in-cell simulations, which provide evidence for the generation of relativistic surface plasmons and for their role in driving the acceleration process. Besides the possible applications of the scheme as a compact, ultrashort source of MeV electrons, these results are a step forward in the development of high-field plasmonics.