The proposed work is to develop a high-efficiency aircraft-qualified Fabry-Perot-based interferometer for the High Spectral Resolution LIDAR (HSRL). Through this Phase I effort, Michigan Aerospace Corporation (MAC) will perform instrument simulations to optimize a photon-recycled fringe imaging receiver to meet the HSRL measurement requirements. Photon-recycled fringe imaging technology incorporates the use of high-efficiency Charge Couple Devices (CCDs) to enable range-gated measurements with high spectral resolution of the atmospheric backscatter from molecules and aerosols. During this Phase I effort, MAC will also perform a thorough investigation of the current state of commercial and customizable CCD technology in order to ensure the highest level of efficiency and range resolution available is achieved. The optimized 355nm receiver will be capable of spectrally separating the aerosol and molecular backscatter components in order to deduce the aerosol to total scattering ratio and aerosol extinction. End-to-end simulations will enable a thorough characterization of the measurement biases introduced from instrument instabilities and enable driving requirements to be formed for a Phase II build. Also during Phase I, solid model receiver concepts and trade studies will be performed to enable a smooth transition to Phase II so that the HSRL receiver can be ready for flight in 2008.