Cavity enhanced absorption spectroscopy : an alternative cw-CRD detection scheme

Narrow band continuous wave (cw) light sources can be used in combination with a high-finesse optically stable cavity to perform sensitive, high-resolution direct absorp tion spectroscopy in an amazingly simple experimental setup, using ideas from the field of cavity ring down (CRD) spectroscopy. The absorption information in the Cavity Enhanced Absorption (CEA) method is extracted from a measurement of the timeintegrated light intensity, rather than from the time-dependence of the light intensity that leaks out of the cavity, as in the pulsed CRD detection scheme