Unexpected detection rate dependence of the intrinsic detection efficiency in single-photon detectors based on avalanche diodes

TL;DR

This study reveals a significant drop in the intrinsic detection efficiency of single-photon avalanche diodes at high detection rates, emphasizing the need for rate-dependent calibration in quantum technologies.

Contribution

It provides a systematic analysis of detection efficiency dependence on event rates and introduces a statistical model for efficiency estimation without timestamped data.

Findings

Detection efficiency drops significantly at detection rates above 10%.

A statistical model can estimate efficiency without timestamped data.

Full detector characterization should include rate sensitivity.

Abstract

Single-photon detectors are a pivotal component in photonic quantum technologies. A precise and comprehensive calibration of the intrinsic detection efficiency is of utmost importance to ensure the proper evaluation of the performance in view of the specific technological application of interest, such as the protection against security breaches in quantum cryptographic solutions. Here we report on a systematic study on and comprehensive analysis of the estimation of the intrinsic detection efficiency of two commercial single-photon detectors based on single-photon avalanche diodes (SPADs) for various mean photon numbers and at high laser pulse repetition rates using different techniques. We observed an unexpected and signifucant drop in intrinsic detection efficiency at detection rates of 10 % and higher relative to the maximum detection rate. It is demonstrated that for data analysis a statistical model for the detection rate conveniently can be used if no timestamped data are available. We conclude that the full characterization of single-photon detectors used in critical applications should include the sensitivity of their intrinsic detection efficiency to high event rates.