The Study of Spectral, Temporal, and Spatial Characteristics of Harmonics Generated at Solid Surfaces.

Spectral, temporal, and spatial characteristics of harmonics generated at solid surfaces interacting with laser radiation t = 27 ps and I ≤ 1.5 × 10[sup 15] W/cm²) are studied. Spectral broadening and a long-wavelength shift of the second harmonic were observed for laser radiation intensities exceeding 5 × 10[sup 14] W/cm². Results of the study of the conversion of spectral parameters and polarization features for the generation of second and third harmonics are presented. Conversion efficiencies for the second, third, and fourth harmonic are 2 × 10[sup -8], 10[sup -10], and 5 × 10[sup -12], respectively. The results obtained are compared with data of analogous studies utilizing shorter pulses. Spectral, temporal, and spatial characteristics of harmonics generated at solid surfaces interacting with laser radiation t = 27 ps and I ≤ 1.5 × 10[sup 15] W/cm²) are studied. Spectral broadening and a long-wavelength shift of the second harmonic were observed for laser radiation intensities exceeding 5 × 10[sup 14] W/cm². Results of the study of the conversion of spectral parameters and polarization features for the generation of second and third harmonics are presented. Conversion efficiencies for the second, third, and fourth harmonic are 2 × 10[sup -8], 10[sup -10], and 5 × 10[sup -12], respectively. The results obtained are compared with data of analogous studies utilizing shorter pulses. [ABSTRACT FROM AUTHOR]