Spectral, spatial, and polarization characteristics of harmonics generated at interaction of intense laser radiation with aluminum foils

Investigations on harmonic generation in laser-matter interaction of Nd:glass laser radiation with solid surfaces have been performed. Detailed measurements were made on the intensity of second, third and fourth harmonics, their polarization properties and spectral distribution, as well as dependencies of these characteristics on intensity and polarization of the incident laser radiation. Intensity dependence of second, third and fourth harmonics for p- polarized laser pump shoed a power law scaling of 1.5, 1.8 and 3.8 respectively. Maximal conversion efficiencies for second, third and fourth harmonic generation were observed in the range of 10-8 to 10-12. For p- polarized laser radiation, the generation efficiency was more than ten and hundred times higher in comparison to that for the s-polarized radiation for second and third harmonics respectively. Among other features, rotation of second harmonic polarization as a function of laser intensity showed a quite different behavior for p- and s-polarized laser radiation, and the second harmonic observed in the specular reflection direction was red-shifted for laser intensity exceeding 5 by 1014 W cm-2.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.