Gaussian-state quantum-illumination receivers for target detection

TL;DR

This paper introduces two practical quantum optical receivers for target detection that outperform classical sensors in high-noise, high-loss conditions, demonstrating significant error-probability improvements.

Contribution

The paper presents the first design of quantum-optical sensors for target detection that are feasible for proof-of-concept experiments and outperform classical sensors in challenging regimes.

Findings

Achieve up to 3 dB gain in error exponent over classical sensors.

First structured optical receivers for quantum target detection.

Effective in high-noise, high-loss environments.

Abstract

The signal half of an entangled twin-beam, generated using spontaneous parametric downconversion, interrogates a region of space that is suspected of containing a target, and has high loss and high (entanglement-breaking) background noise. A joint measurement is performed on the returned light and the idler beam that was retained at the transmitter. An optimal quantum receiver, whose implementation is not yet known, was shown to achieve 6 dB gain in the error-probability exponent relative to that achieved with a single coherent-state (classical) laser transmitter and the optimum receiver. We present two structured optical receivers that achieve up to 3 dB gain in the error exponent over that attained with the classical sensor. These are to our knowledge the first designs of quantum-optical sensors for target detection, which can be readily implemented in a proof-of-concept experiment, that appreciably outperform the best classical sensor in the low-signal-brightness, high-loss and high-noise operating regime.