Negative Feedback Avalanche Diodes for Near-infrared Single Photon Detection

In recent years significant progress has been made in near-infrared single photon detection using Geiger-mode InPbased single photon avalanche diodes (SPADs). A more detailed understanding of these detectors with regard to device design, material growth and device fabrication has led to continual performance improvements. A variety of circuits for enabling SPAD Geiger-mode operation have been proposed and demonstrated as well. However, due to the inherent positive feedback nature of the avalanche process, Geiger-mode SPADs are constrained by certain performance limitations, particularly with regard to counting rate and the absence of photon number resolution. These limitations hinder the use of SPADs in certain applications. By incorporating a negative feedback mechanism into InP-based SPADs, these SPAD performance limitations can be overcome. In this paper, we present a negative feedback avalanche diode (NFAD), which is formed by monolithically integrating a passive negative feedback element with a highperformance InP-based SPAD. We describe the design and operation of the NFAD device, along with basic characteristics such as pulse response and quenching dynamics, as well as the dependence of these characteristics on excess bias voltage and input photon number. We will also review the results of near-infrared single photon counting performance for fundamental performance parameters such as photon detection efficiency, dark count rate, and afterpulsing.