Abstract

With the advent of femtosecond lasers has come the promise of directly measuring ultrafast electron transport effects in technologically important materials. Using a front pump/back probe¹ measurement of transient reflectivity changes, we have observed ultrafast electronic heat transport through thin films of gold. For film thicknesses of 500 - 2000 Å, we find thermal transport occurs on a time scale of 40 - 200 fs. In this regime, the transport of heat seems to be governed by electronic motion, since lattice heat diffusion times are much slower.

© 1987 Optical Society of America