Large-Format Linear-Mode Single-Photon-Sensitive Flash LADAR Receiver

ABSTRACT: A large area, linear mode 950nm-1650nm sensitive avalanche photodiode (APD) LADAR receiver will be developed, characterized, and delivered. Such receivers are needed to enhance the capability of small platforms such as missile interceptors and unmanned aerial systems (UAS). In downward-looking surveillance and targeting applications, high resolution 3D data can penetrate obscuring camouflage and ground cover to acquire and identify hidden targets. The reduced pixel dead time of the linear mode APD, relative to Geiger APD arrays, greatly improves the penetration of obscurants through obscurants, including canopies, and enables sensors to resolve objects closely spaced in range. The capacity of linear-mode APDs to measure signal amplitude also provides an additional dimension of target information to support image processing and analysis. After a detector optimization process, aimed at reducing dark counts and enhancing responsivity, a high gain, low excess noise APD array will be hybridized to a custom LADAR readout integrated circuit. The focal plane array will be tested and characterized, and integrated with LADAR receiver electronics. BENEFIT: The single-photon-sensitive APD technology is ideal for applications where laser power is limited and high-resolution 3D imaging is needed for enhanced situational awareness or navigation. Promising applications include 3D data for targeting, mission planning, vertical obstruction identification, site survey, atmospheric profiling, autonomous navigation, automotive cruise control and hazard avoidance, wavefront sensing, and adaptive optics.