Ultra-High Temporal Resolution Laser Radar (LADAR) Receiver

In Phase I, the performance of existing ultra-low-noise, high-speed avalanche photodiodes (APDs) and readout integrated circuits (ROICs) will be characterized and the performance attributes of the Army Ultra-High-Temporal-Resolution LADAR Receiver demonstrated. Additionally, the impulse response, pulse-pair resolution, and noise characteristics of 30-,40-,50-,and 60-µm diameter variants of existing ultra-low-noise APDs will be measured. These trade studies will quantify: impulse response scaling, pulse-pair resolution, and sensitivity versus detector area, and will allow us to identify a device design that meets the Army’s performance goals. Using the trade study results and APD and ROIC device characterization, the Phase II LADAR receiver will be designed and simulated to meet the solicited requirements, including: sub-nanosecond laser pulse response, a 1.5-micron response, 100-micron diameter APD with the best possible excess noise performance, <500-psec pulse time-of-flight (tof) response and the ability to capture multiple tof and sample 50-psec pulse amplitudes at kHz pulse-repetition rates. At the end of Phase I, the design of all components of a LADAR receiver will be completed, supported by both circuit simulation and empirical measurement of detectors so that in Phase II, the ultra-high resolution LADAR receiver will be manufactured and characterized for integrated into a short-pulse direct-detection LADAR system.