Telic Optics proposes to design a compact infrared zoom lens which uses aspheric and diffractive lenses in a state-of-the-art configuration to meet or exceed the solicitation requirements for an MWIR, F/4.5, 50-200 mm zoom lens contained within a 75x150-mm space envelope. The proposed project includes the evaluation of reimaging and nonreimaging design forms. This involves consideration of cold shield efficiency, required dewar volume, lens MTF, package size and lens complexity. Detailed optical performance analysis including tolerance and thermal analysis will be completed to fully demonstrate design feasibility. A concurrent preliminary mechanical design effort will address critical design and packaging issues. In particular, the zoom mechanisms and athermalization means will be developed to the point where the feasibility of active and passive athermalization strategies can be assessed. Telic Optics has already performed significant research in this field including the several programs culminating in fabricated and tested IR zooms. These include an MWIR, F/3, 30-240-mm zoom and an MWIR, F/2.3 75-254-mm zoom. This prior experience provides a high level of confidence in the success of this proposed phase I project as well as the anticipated phase II and phase III successor projects.