Direct Measurements and Modeling of Avalanche Dynamics and Quenching in SPADs

Single-Photon Avalanche Diodes (SPADs) are a fundamental component of many time-correlated photon counting applications, including high resolution Lidars and 3D imaging systems. However, the stochastic nature of avalanche growth and quenching can result in significant variability in the transient response of SPAD pixels, that can impact their performances, especially for high-speed and low-power applications. To overcome this challenge, an unprecedented characterization technique has been developed that allows for the on-pixel measurement of SPAD transient responses. In this article, we present the details of this novel technique, examine the SPAD stochastic behavior and propose a statistical modeling approach accounting for the stochastic transient behavior of SPAD pixels. SPAD device and quench circuit optimization is crucial for obtaining high performances in high-count rate and low-power applications [1], and this novel technique provides a powerful tool for achieving it. Overall, this new technique, offering significant potential for advancing the capabilities of SPADs in different fields, will be of great interest to researchers and practitioners in the field.