Optimising number resolving photo-detectors using classical post-processing

TL;DR

This paper presents a classical post-processing method to enhance the confidence of number-resolving photo-detectors in quantum optics experiments, particularly addressing issues like loss and dark counts.

Contribution

It introduces a simple classical optimization technique to improve detector confidence, applicable in specific regimes with poor detector performance.

Findings

Improves measurement confidence using classical post-processing

Applicable in regimes with photon-number errors like loss and dark counts

Potentially useful for current experiments with suboptimal detectors

Abstract

Many present day quantum optics experiments, particularly in optical quantum information processing, rely on number-resolving photo-detection as a basic building block. In this paper we demonstrate that a simple classical optimisation technique can sometimes be employed to post-process the detector signature and improve the confidence of the measurement outcome in the presence of photon-number errors such as loss or dark-counts. While the regime in which this technique is applicable is rather restrictive, and will likely not be very useful for the large-scale quantum information processing applications of the future, the ideas presented might be employed in some present-day experiments where photo-detectors are typically very poor.