Infrared–infrared double resonance on a molecular beam of NH3

Abstract

A novel laser spectroscopic method with a molecular beam is successfully demonstrated. This technique is widely applicable for studies of collisional relaxation on a variety of molecular transitions, even when untunable infrared molecular lasers are used. The effect of collision‐induced transitions between the vibration–rotation levels of NH₃ are investigated by infrared–infrared double resonance. It is found that the rate of excitation energy transfer is closely related to the molecular energy level structure.