Abstract

The response of dense alkali metal vapors to resonant excitation by strong lasers has been the subject of a considerable amount of recent work.¹ We report in this context about a time-resolved investigation of 3.41-μm IR laser emission from the 5²S–4²P transition in sodium vapor observed after excitation of the 3P state by a flashlamp-pumped dye laser. The observed laser emission may serve as a diagnostic tool to follow the time evolution of such media and gives direct evidence of an efficient and selective mechanism for populating higher levels: energy pooling collisions² [Na(3P) + Na(3P) — Na(5S, 4D) ...) +Na(3S)].

© 1984 Optical Society of America