Method for characterizing single photon detectors in saturation regime by cw laser

TL;DR

This paper presents an analytical model for single photon detector count probability in saturation, validated with experimental data, including effects like afterpulsing, to improve characterization accuracy.

Contribution

It introduces a new analytical expression that accounts for afterpulsing in detector saturation regimes, validated against real detector data.

Findings

The model accurately fits experimental data across a wide power range.

Detector efficiency and afterpulsing probabilities match manufacturer specifications.

The approach enhances detector characterization in high-power regimes.

Abstract

We derive an analytical expression for the count probability of a single photon detector for a wide range of input optical power that includes afterpulsing effects. We confirm the validity of the expression by fitting it to the data obtained from a saturated commercial Single Photon Detector by illuminating it with a cw laser. Detector efficiency and afterpulsing probability extracted from the fits agree with the manufacture specs for low repetition frequencies.