Frequency Modulated Integrated Cavity Output Spectroscopy: A General Technique for Trace Gas and Isotope Measurements with Unprecedented Sensitivity

A new technique is proposed for improved trace gas detection and measurement that combines the high absorption depths afforded by mid-infrared Integrated Cavity Output Spectroscopy (ICOS) with the added precision and sensitivity of Frequency Modulated Spectroscopy (FMS). To our knowledge, the two-tone FM technique described and prototyped in this proposal is the first demonstration of this combination. This proposal requests funding to advance on the breakthrough preliminary work shown here and to fully realize FM ICOS as a means to achieve one a one order of magnitude increase in detection precision compared to the very sensitive ICOS technique, enabling a new era of trace gas quantification including isotope ratio determinations of carbon, nitrogen and oxygen species.