Desorption induced by femtosecond laser pulses

The yield and final-state distributions in translational and internal degrees of freedom have been established for NO molecules desorbed from a Pd(111) surface by 200-fs pulses of 2.0-eV photons. Among the significant characteristics of the desorption process are the large cross section and the high vibrational energy content (Tv>2000 K) of the desorbed molecules. A comparison with the behavior for nanosecond laser pulses indicates that a new desorption mechanism, distinct from either conventional thermal or photochemical processes, is operative in this regime. © 1990 The American Physical Society.