In contrast with older models, recently developed anti-ship and air-to-air missiles are using sensors that operate in the 8-12 micron region of the spectrum and image the entire ship or plane. Since these modern missiles cannot be spoofed by decoys such as hot flares, the DOD will need other means to defend its valuable assets, such as ships and planes. The proposed ultra broadband source has the potential to provide, at a very modest cost, a unique defense tool against a sophisticated threat. The long term objective of the proposed program is the development of a compact, ultra broadband radiation source that is capable of producing hundreds of watts average power in the spectal regions 3-5 and 8-12 microns from the interaction of the beat wave generated by two carbon dioxide laser beams with a non-linear medium. In addition to its significant countermeasure applications,such a source has an interesting and promising commercial application in the remote sensing of hazardous air pollutants. The main objective of Phase I is to accurately determine the spectral broadening resulting from the interaction of two carbon dioxide laser beams with a dispersive, non-linear medium by solving numerically the transformed wave equation and to optimize the output spectrum in extensive tradeoff studies over a wide range of parameters.