ABSTRACT
This chapter provides an overview of the main experimental methods and techniques currently available to generate and collect (laser-induced) fluorescence—LIF—emission, exploiting either of the two key operation modalities, fluorescence emission or excitation spectrum, depending on whether the excitation or emission wavelength is kept at a preselected value, respectively. The reader will be introduced to two main groups of LIF applications: (1) those dedicated to the study of “bulk” samples (including gas-phase molecular spectroscopy, reaction dynamics, analytical chemistry, and medical diagnosis under steady-state conditions); and (2) those using time-resolved conditions. For the latter, the focus is on the measurements of lifetimes via time-correlated single-photon counting, or on real-time molecular dynamics via femtosecond transition-state spectroscopy. Thereafter, the reader is invited to visit LIF spectroscopy at the small scale, in which—thanks to the integration of microscopy technology—the spectral signatures of even individual molecules can be resolved. Finally, exemplifying the broad wealth of LIF applications, highlights are given, e.g., of the first experiments that employed molecular beams and LIF, to probe the product state distribution of elementary reactions; and of the first FRET measurements of a gaseous ionized protein.
