Abstract

Many molecules are difficult to detect and identify spectroscopically due to the absence of well-defined rotational structure in their infrared absorption bands and to the lack of structured or any absorption in the convenient ultraviolet-visible spectral region. As a means of detection and class identification of such molecules, we are pursuing an approach based on the observation of numerous studies over the past few years that focused excimer laser radiation can lead to substantial fragmentation of a parent compound. (A partial list of representative studies is provided in Ref. 1.) The photofragments typically include di- and triatomics (as well as atoms), which do generally have structured, readily identifiable transition systems in the ultraviolet-visible spectral region. These fragments may be detected by their prompt emission, if formed in electronically excited states, or by probe techniques such as laser-induced fluorescence (LIF) or laser multiphoton ionization (MPI). Detection of distinctive photofragments can lead to identification of the parent. In particular, strongly bound moieties characteristic of a class of compounds may be anticipated to survive the focused laser photolysis.

© 1987 Optical Society of America