One-shot detection limits of time-alignment two-photon illumination radar

Abstract

Quantum radar has recently gained increasing importance in a number of military applications. The estimation accuracy of one-shot quantum illumination events is significant in target detection. However, the accuracy is inevitably deteriorated by measurement noises. The traditional one-shot illumination emits a single photon towards a certain area where thermal noise exists in the path and the states of the received photons are hard to distinguish in the following processing. Therefore, a new optical probe source is proposed in this work. The independent detecting unit in the enhanced illumination is comprised of a two-photon aligned in time by means of Hong-Ou-Mandel (HOM) interferometer. One step further, one-shot detection ability in a general discrete model is realized and it proves a significant promotion in accuracy. The expansion of useful parts in parameter space and the lower minimal error probability for hypothesis testing have been mathematically demonstrated. The accuracy of one-shot detection can be effectively improved by the proposed scheme which infers a great application potential in quantum illumination and imaging.