This Phase I Small Business Innovation Research project aims to develop a low cost single optical photon imaging detector. This detector will support diagnostic systems needing rapidly acquired images obtained from ultra-low levels of light. Examples include: assays for bacterial and yeast contamination in fluids in the food, beverage, pharmaceutical and semiconductor industries; and clinical diagnostics for gene-specific activity screens. Phase I of this project will demonstrate the device concept. Phase II will develop a manufacturing process to support mass production and will initiate the custom design of one or more instruments for specific assays. Offering a suitable detector for a fraction of the cost of current technologies will facilitate the widespread adoption and development of assays that are faster and more accurate than current common practices. Industries in the U.S. will benefit from increased quality and productivity in processes that depend on these assays, and companies that produce the assays will enjoy growth in the demand for their products.