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:
Aug. 20, 2002
Filed:
Mar. 05, 1999
Nicolas Gisin, Geneva, CH;
Bruno Huttner, Collonges-sous-Saléve, FR;
Antoine Muller, Geneva, CH;
Hugo Zbinden, Geneva, CH;
Beat Perny, Kleinbösingen, CH;
Swisscom AG, Bern, CH;
Abstract
A system and method for communicating a key between two stations using an interferometric system for quantum cryptography. The method includes sending at least two light pulses over a quantum channel and detecting the interference created by the light pulses. The interfering pulses traverse the same arms of an interferometer but in a different sequence such that the pulses are delayed when traversing a quantum channel. The pulses are reflected by Faraday mirrors at the ends of the quantum channel so as to cancel any polarization effects. Because the interfering pulses traverse the same arms of an interferometer, there is no need to align or balance between multiple arms of an interferometer.