Relativistic self-trapping of extreme laser light in an inhomogeneous plasma

The possibility of implementing the relativistic self-trapping of an ultraintense laser pulse in a plasma with an inhomogeneous density profile is proved using the three-dimensional kinetic particle-in-cell simulation. The necessary focusing conditions of laser light are determined depending on the gradient length of the plasma density. The comparison of the efficiency of the laser-induced acceleration of electrons with the case of a homogeneous plasma indicates that the appropriate choice of the position of the focus of laser light and the size of the focusing spot on the density profile ensures the relativistic self-trapping of the laser pulse and its use in innovative applications with the same efficiency as in the case of a homogeneous target.