THE ROLE OF THE EXCITATION PROCESS AND NON-EXPONENTIAL DECAY CURVES

Abstract

In the past several years theoretical methods have been developed which allow the treatment of the excitation process of excited state molecules as well as the decay process. The studies have shown that the excitation process in many cases can play a crucial role in determining the type of decay curve which is observed. This is of relevance to the experimentalist using laser excitation where the distinction between coherent and incoherent light sources is essential to many experiments. The theory described here will first describe some simple aspects of the theory of the radiation field with respect to coherence and Incoherence, then discuss its application to various types of excitation-decay experiments. In particular non-exponential fluorescence decay curves will be discussed with the emphasis on why they should appear and what they mean.