Quantum illumination with a parametrically amplified idler

Quantum illumination uses a quantum state of the electromagnetic field to detect presence target against bright background more sensitively than any classical state. Most often, is two-mode squeezed vacuum consisting signal and idler modes with non-zero phase-sensitive cross correlation, which serves as signature for detection, zero phase-insensitive means produce no fringes in second order interference. Here it shown that applying amplification results correlation enabling reception by simple beam splitter photodetectors. It parametrically amplified has lower probability error an asymptotically optimal classical-state scheme discriminating between present absent equal prior probabilities.