Hybrid near-optimum binary receiver with realistic photon-number-resolving detectors

TL;DR

This paper introduces a hybrid receiver for binary phase-shift-keyed coherent states using photon-number-resolving detectors, which outperforms traditional limits and is robust under realistic detector imperfections.

Contribution

A novel hybrid detection scheme combining homodyne-like and direct detection strategies for improved quantum state discrimination.

Findings

The hybrid receiver surpasses the standard quantum limit.

It outperforms the Kennedy receiver in realistic conditions.

The scheme remains near-optimal despite detector inefficiencies and dark counts.

Abstract

We propose a near-optimum receiver for the discrimination of binary phase-shift-keyed coherent states employing photon-number-resolving detectors. The receiver exploits a discrimination strategy based on both the so-called homodyne-like and the direct detection, thus resulting in a hybrid scheme. We analyse the performance and the robustness of the proposed scheme under realistic conditions, namely, in the presence of inefficient detection and dark counts. We show that the present hybrid setup is near-optimum and beats both the standard-quantum-limit and the performance of the Kennedy receiver.