Characteristics of harmonics generated by oblique incidence of a relativistic laser beam on an inhomogeneous plasma

Self-consistent focusing of high harmonics of a relativistic intensity femtosecond laser pulse reflected from a plasma surface is considered. The studied harmonics are summed into a sequence of short intense pulses (attopulses). The plasma parameters (density, inhomogeneity scale) and the laser pulse (intensity, transverse profile) necessary to obtain a given focusing distance of attopulses are determined. The radius of the focusing spot and the intensity of attopulses at the focal point are determined.