Hollow Waveguide Cavity Ringdown Spectroscopy
Greg S. Mungas and Chris Dreyer
Summary: A hollow waveguide cavity ringdown spectroscopy design for measurements of an
absorption medium
Description: This invention is of a hollow waveguide cavity ringdown spectroscopy design for
measurements of an absorption medium. This design provides substantial improvements in a
number of areas associated with traditional cavity ringdown spectroscopy (CRDS)
measurements. For instance, in this design light can be injected through a mirror aperture and
simultaneously contained within the cavity over the entire ringdown profile. This configuration
would enable very large enhancements in injected cavity energy, drastically reducing the laser
power requirements for pulsed-CRDS measurements. Furthermore, for a given laser power
using pulsed-CRDS, this configuration significantly improves any combination of measurement
sensitivity and time by enhancing the signal to noise ratio. The hollow wave guide supports
mode propagation angles that are large enough such that precision tuning of CRDS could be
conducted by altering the injection angle into the waveguide rather than by mechanical tuning
of the cavity. The configuration of the CRDS mirrors within the hollow wave guide is inherently
more robust to optical alignment variations particularly for low-cost instrument development.
Main Advantages of this Invention:
 Design allows for low-cost instrument development
 Reduces laser power requirements for pulsed-CRDS measurements
 Robust design is ideal for mobile applications
 High signal to noise ratio
Potential Areas of Application:
 Adsorption or scattering measurements of gases, liquids, solids, or optical elements
ID number: 7001
Intel ectual Property Status:
US 8,154,727
Opportunity: We are seeking an exclusive or non-exclusive licensee for marketing,
manufacturing, and sale of this technology.
For more information contact:
William Vaughan, Director of Technology Transfer
Colorado School of Mines, 1500 Illinois Street, Guggenheim Hall Suite 314, Golden, CO 80401
Phone: 303-384-2555; e-mail: wvaughan@mines.edu