Laser-induced molecular predissociation without absorption or emission of laser photons

Abstract

Quantum theory and selection rules of laser-induced predissociation of diatomic molecules without actual absorption or emission of laser photons are given. The rate of induced predissociation is a function of the externally controllable laser-field parameters: intensity, frequency, and polarization. Both perturbative and nonperturbative theories are used in the analysis, providing treatment for both low and high laser intensities. The region of validity of perturbative results is determined by comparison with the exact results and is given by a simple criterion. An approximate expression is given for the convenient calculation of the induced predissociation rate. Laser-induced predissociation without absorption or emission of laser photons also occurs in polyatomic molecules, and the analysis is similar.