Abstract

Cavity ring-down spectroscopy is an ultra-sensitive detection technique that exploits light energy stored in a high finesse optical resonator.¹The time constant of the decay of radiation exiting the optical resonator is inversely proportional to the absolute optical losses of the resonator. Thus, by filling the resonator with a sample, such as a gas for example, the absorption losses of the gas can be measured at a given wavelength. If the light source is tunable, the absorption spectrum of the sample can be obtained.

© 2002 Optical Society of America