Dye laser
From Glossary of Meteorology
dye laser
Laser in which the radiation from a fixed-wavelength laser is focused into an organic dye, which then emits at a longer wavelength.
The resulting radiation, usually in the visible range, is tunable, so a much wider range of molecules can be detected. The lasers can be either pulsed or continuous. Uses include lidar, sensing of atmospheric trace gases, particularly free radicals, and the detection of atmospheric gases in laboratory kinetics experiments.