Dynamic collisionless absorption of a laser pulse in a homogeneous plasma by nonlinear forces

At very high laser intensities, the response of plasma is decreased due to the nonlinear effects of the Coulomb collisions and due to a (nonlinear force-induced) decrease in the parametric decay and a relativistic decrease in resonance absorption. The remaining process is the dynamic transfer of optical energy to a homogeneous plasma by nonlinear forces. The process due to the intensity profile of a pulse of finite duration tau0 is studied using time-dependent nonlinear forces. The motion of the initially resting plasma behind the pulse is derived and the highly nonlinear decay length formulated. The absorption is strong at intensities close to or above the relativistic threshold and at plasma densities near the cutoff density