Wide-band quantum interface for visible-to-telecommunication wavelength conversion

TL;DR

This paper demonstrates a wide-band quantum interface that efficiently converts visible photons at 780 nm to telecommunication wavelengths at 1522 nm, preserving entanglement, enabling high-speed quantum communication.

Contribution

First experimental demonstration of visible-to-telecommunication frequency conversion using a nonlinear crystal that retains quantum entanglement.

Findings

Successful conversion of 780 nm photons to 1522 nm photons

Retention of entanglement after frequency conversion

Potential for high-speed quantum communication

Abstract

We perform the first demonstration of a quantum interface for frequency down-conversion from visible to telecommunication bands by using a nonlinear crystal. This interface has a potential to work over wide bandwidths, leading to a high-speed interface of frequency conversion. We achieve the conversion of a pico-second visible photon at 780 nm to a 1522-nm photon, and observe that the conversion process retain entanglement between the down-converted photon and another photon.