Pump-Probe Laser Spectroscopy

Abstract

Understanding the sequence of events that occur following the absorption of a photon is key to our understanding of photochemical reactions and processes. In many reactions there exist metastable or transient species, for example excited electronic states of radicals. These species are by their very nature short-lived, and under conventional reaction conditions their concentration at any instant is vanishingly small - making them virtually impossible to observe. Prior to the introduction of pump-probe techniques the intermediacy of these species could at best be only inferred.