Monitoring atmospheric particulate matter through cavity ring-down spectroscopy

Cavity ring-dawn spectroscopy was explored as a means to measure atmospheric optical extinction. Ambient air was sampled through a window on the campus of the University of Florida and transported to a ring-down cell fashioned from standard stainless steel vacuum components. Mien a copper vapor laser operating at 10 kHz is employed, this arrangement allowed for nearly continuous monitoring of atmospheric extinction at 5 10 and 578 nm. We have characterized the system performance in terms of detection limit and dynamic range and also monitored a change in atmospheric extinction during a nearby wildfire and fireworks exhibition. The sensitivity and compatibility with automation of the technique renders it useful as a laboratory-based measurement of airborne particulate matter.