High-order harmonic generation from a solid surface plasma by usinga picosecond laser

摘要

Investigations have been performed on harmonic generation fromnsolid-vacuum interfaces using a prepulse-free 2.2-ps 1054-nm laser pulsenat maximum intensities of ~1×1015 W·cm-2n. The harmonic intensities were strongest for p-polarized pump andndropped to about 50% in the case of s-polarized pumps. The rationI4wI2w between the intensities of the fourth andnsecond harmonics was 0.25 at IΛ2=6×1014n W·cm-2·Μm2, which isnrelatively large when compared with the value predicted by simulations.nThe harmonics are collimated in the specular direction, with antransverse mode and divergence comparable to that of the driving laser