Mechanism of radiation absorption by condensed targets irradiated by subpicosecond highly contrast laser pulses with an intensity of up to 3×1016 W cm–2

The mechanism of absorption of laser radiation by metal targets exposed to 0.8-ps laser pulses with the contrast ratio above 10¹² and the intensity of up to 3×10¹⁶ W cm^–2 is studied. The reflectivity and the energy of plasma electrons are measured for gold and aluminium targets. The reflectivity measurement data are consistent with calculations by the Drude model for the absorption of a light wave in a plasma of solid-state density in the regime of normal skin effect. An anomalous dependence of the energy of plasma electrons on the polarisation of laser radiation was observed.