This Small Business Innovation Research (SBIR) Phase I project will study and design a tunable infrared source. For many years, spectroscopists have depended heavily on tunable dye lasers and harmonic generators to explore molecular reactions and compounds by their characteristic spectra in the visible and ultraviolet (UV) wavelength regions. More recently, solid state parametric oscillators have become indispensible tools in the UV, visible, and near-infrared (IR). Compared to these wavelength regions, the mid-IR region of 4 to 12 microns is relatively unexplored. Although the mid-IR is rich in rotational/vibrational spectra for molecules, there are no commercial, coherent, tunable mid-IR sources available for spectroscopy. Phase I will develop this important system in a design based on pumping with an Nd:YAG laser, which is a common type of laser in spectroscopy laboratories. Phase II would build a prototype mid-IR laser with features conducive to the laboratory environment, including computer control of the device. A tunable mid-IR source would be used widely in environmental monitoring, chemical and pharmaceutical research, microelectronics manufacturing, and combustion research for the automotive and defense industries.