ABL (Airborne Laser) Detection Sensor Improvements

Recent and emerging technologies, such as a 3-D LADAR tracker with precise target detection, tracking, and aimpoint imaging could make significant gains for ABL’s capabilities. Solid state avalanche photodiodes (APDs) are a rugged, fully-monolithic detector technology well suited for LADAR focal plane arrays (FPAs). In the past, Geiger mode APD operation has been preferred for tasks requiring sensitivity to single photon, but Geiger APDs achieve single photon sensitivity comes at the price of high dark current and long dead times because fundamental tradeoffs exist between detection probability, dark count rate, and speed. Recent advances in low-noise amplifier design and techniques for suppressing APD multiplication noise have brought single photon sensitivity within reach of linear APD systems. This technology has application for a number of the ABL EO systems and in this Phase I program. Through a series of materials growth and fabrication designed experiments, Voxtel proposes to develop, fabricate, and demonstrate a NIR photon-counting linear mode APD capable of sub-nanosecond-scale detection and pulse pair resolution and establish its reliability. In Phase II, a large-format, fully-functional LADAR FPA will be fabricated and tested.