Afterpulsing studies of low noise InGaAs/InP single-photon negative feedback avalanche diodes

TL;DR

This study investigates the afterpulse probability in low-noise InGaAs/InP single-photon avalanche diodes over a wide time range, revealing limitations of existing models and proposing an improved trap spectrum model based on experimental observations.

Contribution

It provides a detailed characterization of afterpulsing in NFADs over extended times and introduces a refined trap spectrum model with experimentally observed edges.

Findings

Extended afterpulse probability characterization from 300 ns to 1 ms.

Existing models based on discrete trap levels are insufficient.

Introduction of a continuous trap spectrum with well-defined edges.

Abstract

We characterize the temporal evolution of the afterpulse probability in a free-running negative feedback avalanche diode (NFAD) over an extended range, from $\sim$300 ns to $\sim$1 ms. This is possible thanks to an extremely low dark count rate on the order of 1 cps at 10% efficiency, achieved by operating the NFAD at a temperatures as low as 143 K. Experimental results in a large range of operating temperatures (223-143 K) are compared with a legacy afterpulsing model based on multiple trap families at discrete energy levels, which is found to be lacking in physical completeness. Subsequently, we expand on a recent proposal which considers a continuous spectrum of traps by introducing well defined edges to the spectrum, which are experimentally observed.