Second generation infrared imaging systems require high density focal plane arrays for both staring and scanned applications. To meet these needs, a focal plane structure using HgCdTe photodiodes for detectors and Si CCDs for signal processing has been developed. Although conventional ion implanted hybrid arrays have successfully been interfaced to CCD multiplexers, hybrid arrays fabricated on LPE layers offer some inherent advantages with respect to performance, processing and yields. It has been determined that hetero-structure diodes fabricated by a Hg infinite melt LPE technique give superior performance relative to conventional ion implanted devices. The devices consist of n-type LPE layers grown on p-type substrates. The layers are n-type as grown and no annealing of the grown layer is required. The deVices exhibit high RoA products and good compositional uniformity. Data will be presented on devices fabricated for both 8- to 12-µm and 3- to 5-µm applications.