Diode-Based Mid-IR Gas Monitors

SDL, Inc. proposes to develop an environmental gas monitor based on a unique mid-IR diode laser source tunable from 2-5 um. The mid-IR is an ideal place to measure gas concentration, since most gases of interest have strong, distinctive absorption lines there; the problem is, there are not cost-effective spectorscopic-quality lasers in the mid-IR that could be used as sources for such an absorption measurement. Given this lack, current absorption sensors are based on broadband lamps or electrochemical cells, which have comparatively poor resolution and sepcificity. However, SDL has developed a technology that can provide a tunable mid-IR source based on coventional diode laser materials in a simple, rugged, robust package. In this program, SDL will develop a complete gas monitoring module combining a tunable mid-IR laser source with optics, control, and calibration electronics that can, by swapping in and out diode sources, be used at any wavelength in the 2-5 um band. The gas sensor developed in this proposal will be small, simple, and low cost, and can be configured for a wide range of gases wavelenths. Anticipated Benefits: Commercial applications range from gas detection in mines, industrial monitoring of pollutants, process gases, and byproduct gases, monitoring and analysis of agricultural processes, and as a detection system for isotopically tagged enzymes in medical and agricultural diagnostics.