Precision reflectivity and ambient light removal for a geiger mode/single photon active sensor system

Abstract

Geiger mode photo diodes are solid state photodetectors that are able to detect single photons. Such Geiger mode photo diodes are also referred to as single-photon detectors (SPDs). An array of SPDs can be used as a single detector element in an active sensing system, but sensor systems based on SPD arrays have at least two shortcomings due to ambient light. First, solar background light can hamper the ability to accurately determine depth. Second, ambient light impacts the reflectivity precision because of challenges differentiating between reflected light and ambient light. Embodiments enable active sensors that remove the ambient signal from a sensor's optical input. Other embodiments produce sensor intensity values that have higher precision than typical SPD array devices. Further embodiments produce sensor depth values that have higher precision than typical SPD array devices.