2(Nd) And 3(Rd) Generation Thermal Imagers Based On Type-Ii Superlattice Photodiodes

We report on the development of InAs/GaSb type-II superlattice focal plane arrays (FPAs) for missile warning systems in airborne platforms. The FPA fabrication technology was developed on the basis of monospectral superlattices for the MWIR (3-5 mu m) spectral range. A monospectral. 288x384 MWIR camera with 24 mu m pixel pitch, a noise equivalent temperature difference (NETD) better than 14 mK and a background-limited performance (BLIP) up to 92 K is demonstrated. Based on the monospectral technology, the first bispectral superlattice camera was realized. The dual color 288x384 superlattice camera features simultaneous, pixel-registered detection of both spectral channels between 3-4 mu m and 4-5 mu m with a NETD better than 30 mK and 17 m-K, respectively. Hence, spatial or temporal registration problems, which are common to most dual color and dual band infrared imagers are solved with the new bispectral MWIR missile alerting sensor.