Theory of photodesorption of molecules by resonant laser-molecular vibrational coupling

Abstract

Photodesorption due to a laser resonantly coupled into an internal vibrational mode of an adsorbed molecule is considered. Based on a master equation with transition probabilities calculated quantum statistically for laser-induced vibrational transitions, phonon-mediated bound-state—bound-state and bound-state—continuum transitions, and tunneling transitions from bound states degenerate with the continuum, we calculate desorption rates as a function of temperature and laser intensity. They are highly nonlinear in both, and become saturated for high intensities. The theory is applied to the C${\mathrm{H}}_3$F-NaCl and CO-NaCl systems.