Polarization effects in harmonic generation from solid surfaces
Аннотация
Investigations on polarization effects in harmonic generation from solid surfaces were performed in the intensity range 1013-1015 W cm-2 using 27 ps Nd:glass laser pulses. For an obliquely incident p-polarized laser beam, second, third and fourth harmonics were observed in the specular reflection direction with intensity scaling exponents of 1.5, 1.8 and 3.8 respectively. Second and third harmonic radiation generated using an s-polarized pump was about ten and hundred times smaller respectively compared to that for the p-polarized laser radiation. While the second harmonic produced by the p-polarized pump was almost fully p-polarized, that for the s-polarized pump had p- and s-components in the proportion of about 1:2. Faraday rotation observed in the polarization of reflected fundamental radiation can explain the relative harmonic yields for the p- and s-polarizations of the pump beam and the polarization structure of the second harmonic radiation.