Ultra-intense single attosecond pulse generated from circularly polarized laser interacting with overdense plasma

Abstract

Few-cycle relativistic circularly polarized (CP) laser pulse reflected from overdense plasma is investigated by analysis and particle-in-cell simulations. It is found that through the laser-induced one-time drastic oscillation of the plasma boundary, an ultra-intense single attosecond light pulse can be generated naturally. An analytical model is proposed to describe the interaction and it agrees well with simulation results. They both indicate that peak intensity of the generated attosecond pulse is higher when the plasma density is closer to the relativistic transparency threshold andor the pulse duration is closer to plasma oscillating period. Two dimensional simulation shows that a two-cycle 1021 Wcm2 CP laser can generate a single 230 attosecond 2 1021 Wcm2 pulse of light at a conversion efficiency greater than 10-2. © 2011 American Institute of Physics.