Interferometric investigation of femtosecond laser-heated expanded states

Simultaneous temporally and spatially resolved measurements of the phase ch ange and reflectivity of S- and P-polarized femtosecond laser probes are ob tained from hot expanded states produced by femtosecond laser heating of a solid aluminum target. The combined set of data provides an integral test o f equation-of-state models in a regime up to 10 Mbar and densities of 0.01- 1 times solid. The results suggest that target stoichiometry at the few A l evel should be considered in the analysis of phase and reflectivity measure ments in such experiments. (C) 2001 American Institute of Physics.