Abstract: A receiver is provided for receiving a multiplexed signal and an optical signal that are transmitted independently through a transmission channel, the multiplexed signal including a first quantum signal (Qn) and at least one polarization state control signal, the optical signal including a second quantum signal (Qh), the receiver having a processing chain and a correlation module associated with a polarization base of at least one polarization state, the chain being designed to determine the polarization state of the control signal and to modify the polarization of the multiplexed signal so as to align the determined state with the state of the base, the module being configured to carry out a correlation measurement between the first and second quantum signals and to generate, based on the measurement, at least one information signal regarding the entanglement state of the first and second quantum signals.

Abstract: A transmitter of a multiplexed signal through a transmission channel includes a generator of an initial quantum signal, of a first reference signal and of a second reference signal, an encoder having N optical channels including a selector for passing the initial signal to one of the channels, and a recombiner for generating the multiplexed signal, the multiplexed signal including first and second signals (R11, R12) for controlling first and second polarization-encoding values (P1, P2), respectively, and a quantum signal, determined based on the initial signal, encoded with an encoding value. The optical channels include two channels each including a unit for integrating a reference signal into the channel, each control signal being determined based on one of the reference signals delivered by the channel in question to the recombiner.

Abstract: An optical communication method comprises modulating an optical carrier (OC) by both first and second electrical signals to provide an optical dual signal (S) comprising quantum (Sq) and classical (Sc) signals, first (Dq) and second (Dc) data being encoded in the first and second signals respectively; transmitting and receiving said dual optical signal (S) to and from an optical propagation medium; extracting the first and second signals from the received dual signal; compensating in the extracted first signal and from the extracted second signal: a frequency mismatch (?f) between a central frequency of the optical quantum signal and a local oscillator optical wave (LO); a phase mismatch (??) between the optical carrier and the local oscillator wave; and decoding the first and second data from the compensated first signal and the extracted second signal respectively.