Ultrashort laser-induced electron photoemission: a method to characterize metallic photocathodes

The photoemission properties of metallic photocathodes are studied by a tim e-resolved single-photon laser technique in the femtosecond regime. Experim ental results obtained for different metals (Au, Cu, W, Al, Fe) are interpr eted by a theoretical model, taking into account electron-electron and elec tron-phonon dynamics during the illumination by ultrashort, high-intensity ultraviolet laser pulses. This model points out the physical process of ult rashort photoemission from metals and the correlation of microscopic transi ent effects with macroscopic steady-state characteristics.