ABSTRACT
This chapter presents a picture of the impact of lasers on high-resolution gas phase molecular spectroscopy by concentrating on certain key areas. It considers both the armory of techniques available for carrying out high-resolution spectroscopy, and also the use of combinations of methods for studying small polyatomic molecules, which are of considerable interest because of chemical reactions, or for testing current models of vibration-rotation interaction and of dipole moment variation. Electronic spectroscopy was one of the first techniques used to study the absorption and emission spectra of small molecules, as photographic plates could be used to record electronic spectra in the visible and ultraviolet regions. Stark spectroscopy has been used for two main purposes: as a high-resolution spectroscopic method for measuring the absorption spectra of low pressure gases, particularly of short-lived species, and for the accurate measurement of electric dipole moments.
