Enhanced Focal Plane Array Technology

A high pixel density, near-infrared (NIR), 200 fps, germanium focal plane array (FPA) with laser pulse response times from CW down to 10 nsec will be designed, characterized, and demonstrated effective in reducing the uncertainty in radiometric field measurements of high-energy laser (HEL) spatial distributions. The bandgap and high carrier mobility of germanium make it ideal for high-speed, fast-response, NIR imaging, and germanium photodetectors are well-established, highly-stable, NIR calibration reference detectors. However, processing CMOS circuits directly on germanium is difficult. High-speed silicon CMOS imagers have been built, albeit with only visible light sensitivity. Thus, while neither silicon nor germanium by itself embodies a perfect set of properties for the large-scale fabrication of NIR-sensitive FPAs, when these materials are brought together using reliable high-interconnect-density, 3D-stacked-circuit technology, robust, high frame rate, high-resolution NIR FPAs, with pixel pitch below 10 microns, can be manufactured using commercial, high-volume CMOS processes. This engenders rapid commercialization, high quality, and a lower cost than contemporary NIR FPA technologies. The proposed Phase II stepwise development program demonstrates each of the technological components individually and then integrated into a fully-functional HEL radiometric FPA, which will be characterized and its performance demonstrated for the application.