Revisiting mechanisms of molecular contamination induced laser optic damage

A revision of a theoretical mechanism proposed last year based upon the known chemical and physical interactions of laser radiation, fused silica, aromatic molecules and environmental factors will be presented, as relates to other proposed mechanisms. This paper specifically addresses the interaction of toluene with 1064nm laser radiation as related to the formation of benzyl radical, and to free radical photochemistry of toluene. This will address specifically, the effects of oxygen and water in the system, the effects of hydroxyl radical in the system, the interpretation of the XPS spectra of laser damaged silica in the presence and absence of aromatic hydrocarbons and the relationship of these points to the photochemistry of silica.