
%0 Journal Article
%A Shorten, Richard A. 
%A He, Yabai 
%A Orr, Brian J. 
%T Swept-Cavity Ringdown Absorption Spectroscopy: Put Your Laser Light In and Shake It All About
%J Australian Journal of Chemistry
%D 2003/03/20
%V 56
%N 3
%P 219-231
%K 
%R https://doi.org/10.1071/CH02220
%U https://www.publish.csiro.au/paper/CH02220 
%X Cavity ringdown (CRD) absorption spectroscopy with continuous-wave (cw) tunable coherent light sources provides a convenient, sensitive, and precise way to measure very weak optical absorption spectra and to analyze trace gas concentrations. Several recently introduced innovations in cw-CRD spectroscopy are described. Our approach involves one or more single-mode tunable diode laser sources, a rapidly swept ringdown cavity, and a simple optical heterodyne detected approach (based on the dynamics of coherent light reflected from such an active optical cavity). This offers high performance in a relatively simple, low-cost, compact instrument that is facilitated by fibre optic and other standard photonics or telecommunications components. New experimental results are reported, comprising CRD spectra of water vapour in the 0.815 &#181;m wavelength region and of mixtures of CO2 and CO in the range of 1.56&#8211;1.59 &#181;m. Promising applications of such techniques include chemical analysis of trace gases in medicine, agriculture, industry, and the environment. 
