The technology development facility (TDF) in the Earth Observing Laboratory at the National Center for Atmospheric Research (NCAR) is one of many groups around the world utilizing tunable infrared laser (IR) absorption spectroscopy to improve our understanding of the atmosphere and the chemical and physical transformations that occur in different regimes. In addition to laboratory studies, this technology has been successfully employed by various groups in rather diverse field environments and platforms, including: ground, airborne, balloon-borne, ship-borne, and space-borne platforms. The present talk will briefly summarize the fundamentals and potential of this technology and discuss state-of-the-art advances by the TDF group in developing and deploying a new IR spectrometer based upon difference frequency generation (DFG). In addition to ground-based and airborne measurements of important trace gases like formaldehyde and methane, TDF personnel are further developing this technology for high precision carbon dioxide isotope ratio measurements. Highlights of these developments along with a brief discussion how such measurements are being employed to improve our understanding of the Earth's atmosphere will also be presented.