Patent ID: 7019875

Claim:
A source for a single photon for uses related to quantum computing, comprising: an optical switch with an optical input spatial mode and two optical output spatial modes, wherein a photon is directed to one of the two output spatial modes based on a selectable state of the optical switch; a storage loop for directing a photon from a loop mode of the two output spatial modes of the optical switch to the input spatial mode of the optical switch; a source for a pair of photons; a single-photon detector that outputs a detector electric signal when a photon is incident on the single-photon detector; an optical coupler that directs a first photon of the pair of photons to the single-photon detector and a second photon of the pair of photons to the input spatial mode of the optical switch; and an electronic processor connected to the single photon detector and the optical switch, wherein the electronic processor is configured for setting a first state of the optical switch based at least in part on the detector electric signal that is output from the single-photon detector.