Mid Infrared Laser Sources for Remote Sensing, Year 4

Mid infrared solid-state lasers are made possible by using innovative low phonon energy materials. Until recently, such lasers were not feasible because they characteristically had a short upper laser level lifetime. Thus, they were unable to store much energy and accumulate a high laser gain. By using a low phonon energy laser materials, nonradiative losses from the upper laser level can be minimized. In turn, the upper laser manifold lifetime increases, thus the laser gain. An innovative laser design can also be used with mid infrared lasers to provide enhanced detection capabilities. As a principle of parsimony with provided funding it is wise to choose the best candidates to examine first. These would be Pr and Dy for targeting CH4 (methane) and CO. Using earlier spectroscopic studies, lasers can be designed to operate on MIR transitions in low phonon materials. If successful, MIR lasers can be further developed for a variety of Ln3+ ions in low phonon hosts to address various MIR spectral regions. The impact is clear and in the MIR region, broad spectral coverage buys access to chemical "fingerprints," where molecules can be detected and distinguished with great sensitivity. In fact, the region of the MIR from 3 to 10 μm has distinct 'Fingerprint Regions' of interest for remote sensing, specifically 3-5 & 7-10 µm.