Higher harmonics generation for intense laser radiation in plasma created by a prepulse acting on the surface of a solid target

Research on higher harmonic generation in laser plasma is reviewed. Conditions for generating harmonics up to the 101st order ($\lambda=7.9$ nm) are analyzed for laser radiation propagating through a weakly ionized plasma created on the surface of various targets by an incident laser prepulse. Results on resonant increase in the intensity of individual harmonics in a number of plasma systems are discussed which demonstrate greatly increased conversion in the region of plateau-like harmonic distribution (as exemplified by the efficiency of $10^{-4}$ for the 13th harmonic in indium plasma). Data on harmonic generation in nanoparticle-containing plasma are presented. Various methods for increasing the intensity and order of generated harmonics are discussed.