Energy threshold effects in the collisionless dissociation of polyatomic molecules by ir laser radiation

Abstract

The threshold for collisionless dissociation of SF₆, SiF₄, and CF₂Cl₂ by focused CO₂ laser radiation has been measured. This threshold is a laser pulse energy effect and, within experimental error, is found to be the same for all three gases. Provided collisions cannot occur during the laser pulse, the degree of dissociation produced depends only on the energy in the pulse, which is consistent with simple adiabatic vibrational heating of the molecules by the laser.