Quantum illumination receiver using double homodyne detection

Abstract

A quantum receiver is an essential element of quantum illumination (QI), which outperforms its classical counterpart, called classical illumination. However, there are only few proposals for realizable quantum receiver, which exploits nonlinear effects leading to increasing the complexity of receiver setups. To compensate this, in this paper, we design a quantum receiver with linear optical elements for Gaussian QI. Rather than exploiting nonlinear effect, our receiver consists of a 50:50 beam splitter and homodyne detection. Using double homodyne detection after the 50:50 beam splitter, we analyze the performance of the QI in different regimes of target reflectivity, source power, and noise level. We show that our receiver has better signal-to-noise ratio and is more robust against noise than the existing simple-structured receivers.