Effect of crater formation on the absorption of focused laser light

We use a new computational model to investigate the absorption of a focused beam of circularly polarized laser light, including the ponderomotive force. We find, in agreement with recent experiments, that at high intensity large craters can form due to the variation of the ponderomotive force across the focal region. The critical surface becomes concave and the walls of the crater refract the incident light so that resonant absorption can be greatly enhanced