Coherent sensing performance comparison of framed and asynchronous GMAPD arrays

Single photon counting Geiger mode avalanche photodiode (GMAPD) arrays are typically used for high-resolution 3D ranging. These high-gain, high-bandwidth detectors are also feasible for coherent sensing. GMAPD arrays have two different readout architectures: asynchronous and synchronous (or framed). The individual pixels in asynchronous GMAPD arrays operate independently, reducing the loss due to blocking during the reset time. In contrast, framed GMAPD arrays are prone to saturation as they reset the entire array of pixels simultaneously. This study presents a performance comparison of asynchronous and framed GMAPD arrays for coherent sensing as a function of common system parameters. Expressions for the arm probability and blocking loss are defined to contrast the mechanisms of missed detection opportunities for both types of GMAPD detectors.