Minimum transmitted photon quantum optical communications system
US7302187B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 2004 |
| Grant date | Nov 27, 2007 |
| Priority date | — |
| Expiry date | Aug 3, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/85
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.