Focusing of Intense Laser via Parabolic Plasma Concave Surface

Since laser intensity plays an important role in laser plasma interactions,a method of increasing laser intensity- focusing of an intense laser via a parabolic plasma concave surface- is proposed and investigated by three-dimensional particle-in-cell simulations.The geometric focusing via a parabolic concave surface and the temporal compression of high harmonics increased the peak intensity of the laser pulse by about two orders of magnitude.Compared with the improvement via laser optics approaches,this scheme is much more economic and appropriate for most femtosecond laser facilities.