The role of excited species in UV-laser materials ablation

UV-laser ablation is described in terms of a two-level system in which the excitation energy is dissipated via stimulated emission, thermal relaxation, and activated desorption of excited species. For thermal relaxation times t _T>10^–9 s and E* E (activation energies for excited-state and ground-state species) the model predicts high ablation rates at moderate surface temperatures, typically below 2000° C.On leave from General Physics Institute, Russian Academy of Sciences, 117942 Moscow, RussiaOn leave from Institute of Applied Physics, Russian Academy of Sciences, 603600 Nizhnii Novgorod, RussiaOn leave from L.D. Landau Theoretical Physics Institute, Russian Academy of Sciences, 142432 Chernogolovka, Moscow region, Russia