Measuring photon correlation using imperfect detectors

TL;DR

This paper investigates how the recovery process of imperfect single-photon detectors affects their ability to accurately measure photon correlations, revealing an interdependent relationship between detector efficiency, photon statistics, and light intensity.

Contribution

It introduces a model linking detector recovery effects with photon statistics and demonstrates this experimentally using multiple detectors and pseudothermal light.

Findings

Detector recovery suppresses photon counting accuracy.

Photon statistics influence detector efficiency during recovery.

Experimental validation with multiple detectors confirms the model.

Abstract

Single-photon detectors are ``blind" after the detection of a photon, and thereafter display a characteristic recovery in efficiency, during which the number of undetected photons depends on the statistics of the incident light. We show how the efficiency-recovery, photon statistics and intensity have an interdependent relationship which suppresses a detector's ability to count photons and measure correlations. We also demonstrate this effect with an experiment using $n$ such detectors to determine the $n^{\mathrm{th}}$ order correlation function with pseudothermal light.