High-Resolution Spectroscopy

Abstract

Classical high-resolution spectroscopy had been of interest for the sake of studies related to isotope shifts and hyperfine interactions and for resolving complex spectra associated with heavy elements like lanthanides and actinides. In this chapter, some of the history of classical high-resolution spectroscopy has been described. The highest-resolution laser spectroscopy is usually performed with CW lasers which have inherent ultra-narrow linewidths. Pulsed dye lasers though have relatively large linewidth because of Fourier transform limit but can still be usefully employed for multicolor laser spectroscopy of various elements with complex spectra. We have demonstrated the utility of pulsed dye lasers for studying lanthanides and actinides by employing techniques like multicolor optogalvanic spectroscopy in hollow cathode discharges, multicolor laser-induced fluorescence, and resonance ionization spectroscopy in atomic beams. We have for the first time utilized ICCD-based spectrograph for some of the measurements. These techniques have yielded excellent new information on atomic parameters like radiative lifetimes, branching ratios, and absolute transition probabilities of singly or multiply excited atomic levels. These techniques have inherent simplicity and may offer themselves as excellent alternative to conventional techniques and have universal applications of interest to wide cross section of atomic spectroscopists.