Patent ID: 8761606

Claim:
A detection system comprising: a transmitter including: a quantum frequency entanglement source for outputting an output beam including a signal beam and an idler beam, wherein the photons in the idler beam are quantum-mechanically entangled in frequency with corresponding photons in the signal beam; transmission optics for directing the signal beam towards a remote surface; and a first spectrometer for measuring a frequency band associated with photons in the idler beam; a receiver including: a beam collector for receiving a return beam including photons from the signal beam reflected by the remote surface; a second spectrometer for identifying the frequency band associated with the photons in the received return beam; and a frequency splitter for splitting the received return beam into a series of frequency bands associated with the received return beam, the frequency splitter being tunable to the frequency band associated with the photons in the received return beam; and a processor in communication with the receiver and the transmitter configured to process the outputs of the first and second spectrometers to determine one of the presence of a target in a target region or a message encoded within the received return beam.