Improved receiving device for an edge-to-ground interface of a quantum information network

Abstract

Improved receiving device for a ground-to-surface interface of a quantum information network. This device (10) comprises: an optical unit (11) for capturing an entangled photon emitted at an emission frequency ( ) from a satellite (3), a frequency converter (16), and a quantum memory (14) for storing entangled photons, the frequency converter comprising: a nonlinear crystal (50); a tunable source (52); and control means (54) for the tunable source, the nonlinear crystal generating a secondary entangled photon from the captured entangled photon and a conversion photon generated by the tunable source, the control means controlling the tunable source to modify a generation frequency of the conversion photon so that the secondary entangled photon is compatible with the quantum memory, while the captured entangled photon has its emission frequency affected by a Doppler shift due to the satellite's movement.Figure for the abbreviation: Figure 1.

Claims

entangled, towards a receiving device (10) incorporating a quantum memory (34) for storing entangled photons, the emission device (30) being characterized in that it further comprises a frequency converter interposed between the source of entangled photons and the optical unit, the frequency converter comprising: - a frequency conversion means comprising a non-linear crystal and optical components; - a tunable source for generating a conversion signal (Cl) comprising conversion photons; and, - control means for the tunable source, the non-linear crystal of the frequency conversion means being capable of generating a secondary entangled photon from, on the one hand, the entangled photon generated by the entangled photon source and, on the other hand, a conversion photon emitted by the tunable source, the control means driving the tunable source so as to modify a conversion frequency with which the tunable source generates the conversion signal so that the secondary entangled photon has, once affected by a Doppler shift during its transmission between the satellite and the ground station, a frequency adjusted to an input frequency band characteristic of the quantum memory of the receiving device.

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