The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 27, 2007
Filed:
Dec. 08, 2004
Mark W. Roberts, San Diego, CA (US);
Markham E. Lasher, La Jolla, CA (US);
Mark W. Roberts, San Diego, CA (US);
Markham E. Lasher, La Jolla, CA (US);
United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A system parametrically down-converts a photon into a pair of first and second quantum-entangled photons. A transmitter is coupled to receive the first photon and includes an irreversible collapse event device for collapsing the quantum-entangled state of each photon in the pair. The collapse is caused by attempting to detect the first photon at the transmitter. Because of quantum-entanglement, collapse of the first photon collapses the second photon of the pair. The transmitter can also be used to not cause the collapse. A receiver includes polarization detectors to detect whether the transmitter has collapsed or left uncollapsed the quantum-entangled state of the photon pair. Causing or not causing the collapse can be used for communication. Every down-converted photon can be used for communication, even though few of the photons actually leave the source and reach the transmitter. This allows communication with a minimal number of transmitted photons.