On-demand single-photon sources emitting pure and indistinguishable photons at the telecommunication wavelength are a critical asset towards the deployment of fiber-based quantum networks. Indeed, single photons may serve as flying qubits, allowing communication of quantum information over long distances. Self-assembled InAs quantum dots embedded in GaAs constitute an excellent nearly deterministic source of high quality single photons, but the vast majority of sources operate in the 900-950 nm wavelength range, precluding their adoption in a quantum network. Here, we present a quantum frequency conversion scheme for converting single photons from quantum dots to the telecommunication C band, around 1550 nm, achieving 40.8% end-to-end efficiency, while maintaining both high purity and a high degree of indistinguishability during conversion with measured values of g(2)(0)=2.4% and Vcorr=94.8%, respectively.
@article{arxiv.2201.02465,
title = {A Pure and indistinguishable single-photon source at telecommunication wavelength},
author = {Beatrice Da Lio and Carlos Faurby and Xiaoyan Zhou and Ming Lai Chan and Ravitej Uppu and Henri Thyrrestrup and Sven Scholz and Andreas D. Wieck and Arne Ludwig and Peter Lodahl and Leonardo Midolo},
journal= {arXiv preprint arXiv:2201.02465},
year = {2022}
}