Infrared-visible double-resonance ionization spectroscopy

For the first time multiphoton ionization of a molecule (NO) was observed as a result of the sequential excitation by a tunable infrared laser and a tunable dye laser. These double-resonance experiments have made it possible to obtain multiphoton ionization spectra (MIS) of specific rotational levels of the molecule selected by the initial IR transition. The following applications of this technique are demonstrated: a means of simplifying complex multiphoton ionization spectra of molecules, a means of sensitively and selectively detecting IR absorption of molecules, a means of studying the dynamics of relaxation of molecules in excited rotation-vibration states. 5 references