Photon Counting Chirped Amplitude Modulation Ladar

This work is a follow-up to prior efforts to develop a method using Geiger-mode avalanche photodiode (GM-APD) photon counting detectors in chirped amplitude modulation (AM) ladar receivers to yield sensitivities approaching the shot noise limit. Such sensitivities represent about four orders of magnitude improvement over the sensitivities of the currently used unity-gain, opto- electronic mixing (OEM) metal-semiconductor-metal (MSM) detectors. These sensitivity improvements may enable compact, low-power, eye-safe, and/or long-range ladar with low-cost, low-bandwidth readout integrated circuits for foliage and camouflage penetration, target ID, manned and unmanned ground and air vehicle navigation, 3D face recognition, battle damage assessment, and change detection.