The study of spectral, temporal, and spatial characteristics of harmonics generated at solid surfaces

Spectral, temporal, and spatial characteristics of harmonics generated at s olid surfaces interacting with laser radiation (t = 27 ps and I less than o r equal to 1.5 x 10(15) W/cm(2)) are studied. Spectral broadening and a lon g-wavelength shift of the second harmonic were observed for laser radiation intensities exceeding 5 x 10(14) W/cm(2). Results of the study of the conv ersion of spectral parameters and polarization features for the generation of second and third harmonics are presented. Conversion efficiencies for th e second, third, and fourth harmonic are 2 x 10(-8), 10(-10), and 5 x 10(-1 2) respectively. The results obtained are compared with data of analogous s tudies utilizing shorter pulses. (C) 2000 MAIK "Nauka/Interperiodica".