Channel-selective frequency up-conversion for frequency-multiplexed quantum network

TL;DR

This paper demonstrates a method for channel-selective frequency up-conversion from telecom to visible wavelengths, enabling reconfigurable switching and Bell-state measurements in frequency-multiplexed quantum networks.

Contribution

It introduces a cavity-based frequency up-conversion technique that selectively converts telecom signals to visible wavelengths, advancing quantum network capabilities.

Findings

Achieved selective frequency up-conversion within telecom bands

Derived signal-to-noise ratio at the single-photon level

Showed potential for reconfigurable quantum network switching

Abstract

We demonstrate channel-selective frequency up-conversion from telecom wavelengths around 1540 nm for optical fiber communication to visible wavelengths around 780 nm, based on second-order optical nonlinearity in a cavity of the converted modes. In our experiment, we selectively convert a light from any frequency mode within frequency-multiplexed telecom signals to a desired output mode, determined by the cavity resonances. Based on the experimental results of the frequency up-conversion, we derive the signal-to-noise ratio of the process at the single-photon level, and discuss its applicability to channel-selective quantum frequency conversion (CS-QFC) in the context of frequency-multiplexed quantum networks. Finally, we describe specific use cases of the CS-QFC, which show its utility as a reconfigurable switching element in frequency-multiplexed networks, particularly for selectively performing Bell-state measurements between two photons originating from different frequencies.