An integrated fiber trap for single-ion photonics

We report on a novel single-photon source using a single calcium ion trapped between the end facets of two optical fibers. The optical fibers act as photonic channels, and in addition their metallic jackets provide a trapping electric field for the ion. Our system successfully combines a stable single-atom emitter with fiber optics, demonstrating remarkable compactness and scalability. In consequence, it is very well suited for use in quantum networks, where single ions interface with single photons traveling through optical fibers. We have demonstrated the non-classical character of the photons generated by this efficient source in continuous as well as pulsed mode.