Abstract

Experimental, investigations of the irradiation of a metal surface with femtosecond laser pulses have shown that strongly nonequilibrium transient conditions can be induced.^1-3 Although the energy initially deposited by the laser in electronic excitation thermalizes rapidly in the electronic degree of freedom, equilibration with the lattice occurs on a slower (~1-ps) time scale. This leads to a regime in which the excitation is isolated in the electrons and high electronic temperatures can be attained with little lattice excitation. Femtosecond pumping thus allows us to address some longstanding issues regarding the role of electrons in gas-surface dynamics^4,5 that have proved difficult to investigate by other means.

© 1991 Optical Society of America