Gaussian-state quantum-illumination receivers for target detection

TLDR

Entangled twin‑beam illumination interrogates high‑loss, high‑noise regions suspected of containing a target. The study proposes two structured optical receivers that improve target‑detection error exponent by up to 3 dB over classical sensors. The receivers perform a joint measurement on the returned light and the retained idler beam. The proposed receivers achieve up to 3 dB error‑exponent gain and outperform the best classical sensor in the low‑brightness, high‑loss, high‑noise regime, while an optimal but unknown receiver could reach 6 dB.

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 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.