Role of Plasma Mirror in Light Sail Regime

The interaction of ultra-intense laser pulses with overdense plasmas has made it possible to open up new regimes of radiation pressure dominated acceleration, and especially lately the light sail (LS) regime. It is in this connection that plasma mirrors, i.e., self-generated, overdense, plasma layers generated at the surface of the target, play an important role in mediating a flow of momentum from the laser to the target. In this paper an integrated theoretical and phenomenological analysis of momentum transfer from high-power lasers to plasma mirrors is presented, which includes mechanisms of relativistic dynamics and non-linear interactions of lasers with plasma and scaling laws applicable to the experimental extremes. We discuss the formation and development of plasma mirrors, optimized laser parameters and plasma parameters giving maximum momentum coupling between plasma and electrons, and propose the application fields in ion acceleration, high harmonic generation, and ultrahigh field physics. Recent developments in high repetition rate mirrors and liquid targets are included in order to bridge the gap between theory and emerging technology.