Trace gas sensor based on a novel room temperature mid-infrared laser source

We propose here to develop a practical multi-species sensor for atmospheric gas concentrations and fluxes. The sensor will be based upon Tunable Diode Laser Absorption Spectroscopy (TDLAS), which is a highly sensitive and selective measurement technique. The practicality of this technique has up to now been limited by the use of cryogenically cooled diode lasers. In this work, a compact room temperature sensor will be enabled by a novel mid-infrared laser source developed by Aculight. The source is based upon direct nonlinear frequency conversion of near-infrared diode lasers, by an optical parametric oscillator (OPO). In phase I, we propose to demonstrate the multi-species sensor capability of the device by measurement of methane isotope ratios and formaldehyde concentrations. Potential detection sensitivities for relevant species within the 1 to 4um tuning range of the OPO will be analyzed. In phase II we will upgrade the power level, frequency control and device engineering to provide a deliverable source compatible with ultra-sensitive automated monitoring of multiple species.