We demonstrate multiphoton interference using a resource-efficient frequency multiplexing scheme, suitable for quantum information applications that demand multiple indistinguishable and pure single photons. In our source, frequency-correlated photon pairs are generated over a wide range of frequencies by pulsed parametric down conversion. Indistinguishable single photons of a predetermined frequency are prepared using frequency-resolved detection of one photon to control an electro-optic frequency shift applied to its partner. Measured photon statistics show multiplexing increases the probability of delivering a single photon, without a corresponding increase to multiphoton events. Interference of consecutive outputs is used to bound the single-photon purity and demonstrate the non-classical nature of the emitted light.
@article{arxiv.1907.10355,
title = {Pure Single Photons from Scalable Frequency Multiplexing},
author = {T. Hiemstra and T. F. Parker and P. C. Humphreys and J. Tiedau and M. Beck and M. Karpiński and B. J. Smith and A. Eckstein and W. S. Kolthammer and I. A. Walmsley},
journal= {arXiv preprint arXiv:1907.10355},
year = {2020}
}