NSF Award
9561095
9561095 Linden This Small Business Innovation Research (SBIR) Phase I project develops a new, wavelength-multiplexed, monolithic semiconductor laser array for use in a spectrometer capable of simultaneous detection of a variety of gases in absolute trace concentrations. Simultaneous, multitrace gas detection is presently possible only with complex and very expensive multilaser systems or with FTIR instruments which do not have trace gas sensitivities approaching those demonstrated by tunable diode laser spectrometers. The recent (1994) discovery and demonstration of the quantum cascade laser (an unipolar, mid-IR, semiconductor laser) enables a completely new manufacturable, junction-free semiconductor laser source, which can be multiplexed over a large number of preselected wavelength regions in the mid-IR. Such a tunable, multiwavelength laser source can simultaneously sense traces of a large variety of gases in the atmosphere. This research will design, develop, and demonstrate a monolithic, addressable, multiwavelength tunable, quantum cascade laser array for gas and trace gas detection. Phase II would look at epitaxial growth of complex quantum well laser structures, laser array fabrication, evaluation, spectrometer system design, and prototype evaluation. It is anticipated that this research will produce a portable, ultra-high sensitivity, multigas, mid-IR spectrometer. Potential commercial applications include simultaneous trace gas detection of a wide variety of atmospheric pollutants, hazardous gaseous species, explosive decomposition products, and biological agents. Such an instrument can also be used for chemical process monitoring, studies of complex chemical kinetics, medical diagnostics, and environmental surveillance.
