Nanosecond time-resolved reflectivity determination of the melting of metals upon pulsed laser annealing

Thin metal fiIrns (Cu, Au, Ni) on quartz glass were illuminated with nanosecond pulse.; of a frequency doubled Nd:YAG laser (A = 532 nm). The transient reflectivity behavlour was probed at the wavelength 633 nm, where these metals exhibit Drude-Iike optical behaviour: the reflectivity decreases with temperature in the solid and in the Iiquid state as well as at the solid-llquid phase transition. It is shown that nanosecond time-resolved reflectivity measurements can lx used to d e t e m n e the melting of these metal surfaces due to the reflectivity d~fference between the solid and the liquid phase.