The Small Business Innovative Research Phase I proposal seeks to develop a compact, room-temperature widely tunable middle infrared laser source that will be ideal for detecting methane, it's isotopes and related species using ultrasensitive absorption spectroscopies. The broad tuning ability of the laser will also enable the detection of multiple gas-phase trace species in planetary atmospheres with high selectivity. The laser source will be engineered to be ideally suited for use with high finesse multipass cells, including cavity-ringdown cells. During Phase I, a spectral region of tens of nanometers near 3.3 μm will be demonstrated, which overlaps the spectral absorption features of methane, 13CH4, and formaldehyde. When combined with high sensitivity absorption methods, the laser system will enable these species to be detected at concentrations of less than 1 ppbv in the Martian atmosphere.