Ultrafast electron transport phenomena in highly excited gold films

Non-equilibrium dynamics of hot electrons in highly excited gold films has been investigated by using the femtosecond transient reflecting grating met hod. Transport processes which compete with electron-phonon coupling proces ses were investigated by observing thermal surface displacements. The resul ts were compared with calculations by a simple thermoelastic equation and t he two-temperature model with two different conditions for the thermal cond uctivity. The results suggested that non-thermal states of the hot electron s still contribute transport processes on lime scales of several picosecond s. (C) 1999 Elsevier Science B.V. All rights reserved.