Secured optical communications using quantum entangled two-photon transparency modulation

摘要

A system and method is disclosed wherein optical signals are coded in a transmitter by tuning or modulating the interbeam delay time (which modulates the fourth-order coherence) between pairs of entangled photons. The photon pairs are either absorbed or not absorbed (transparent) by an atomic or molecular fluorescer in a receiver, depending on the inter-beam delay that is introduced in the entangled photon pairs. Upon the absorption, corresponding fluorescent optical emissions follow at a certain wavelength, which are then detected by a photon detector. The advantage of the disclosed system is that it eliminates a need of a coincidence counter to realize the entanglement-based secure optical communications because the absorber acts as a coincidence counter for entangled photon pairs.

主权项

1. An optical communications apparatus for coding optical signals by tuning interbeam delay time using the femtosecond timescale between a pair of entangled photons, comprising:
means for implementing a non-linear optical process to generate the pair of quantum entangled photons; an interferometer to receive the pair of quantum entangled photons to generate a entangled-photon beam; an electro-optical system to encode entangled photon pairs, wherein a relative path delay between the pair of quantum entangled photons are tuned or modulated using femtosecond resolution; and a transmitter to transmit the pair of quantum entangled photons, wherein the pair of quantum entangled photons are received at an absorber where absorption followed by fluorescence emission occur at a certain wavelength, based on an encoded relative path delay of femtoseconds in the pair of quantum entangled photons, and wherein a fluorescence signal is detected by a detector.