The present PHD work aims at exploring theoretically and numerically the generation of fast particle beams in ultra-relativistic (above 10^21 W/cm2) laser-overdense solid interaction by using properly-structured or shaped targets. Surface characteristics inducing local electromagnetic modes more intense than the laser field and where nonlinear and relativistic effects play a major role will be investigated.

On the basis of the work already carried out, the new scheme for particle acceleration will be extended in the ultra-relativistic regime of laser plasma interaction. It may lead to groundbreaking ultra-short synchronized light and electron sources with applications in probing ultrafast electronic processes. In this context, this theoretical and numerical study will allow to suggest new experimental schemes feasible on the Apollon facility and multi-PW lasers.