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. 07, 2007
Filed:
Nov. 21, 2005
Alexei Trifonov, Boston, MA (US);
A. Craig Beal, Watertown, MA (US);
Alexei Trifonov, Boston, MA (US);
A. Craig Beal, Watertown, MA (US);
MagiQ Technologies, Inc., New York, NY (US);
Abstract
An optical fiber interferometer () with relaxed loop tolerance, and a quantum key distribution (QKD) system () using same is disclosed. The interferometer includes two optical fiber loops (LPand LP). The loops have an optical path length (OPL) difference between them. A polarization-maintaining (PM) optical fiber section () of length (L) and having fast and slow optical axes (Aand A) optically couples the two loops. The length and fast-slow axis orientation is selected to introduce a time delay (ΔT) between orthogonally polarized optical pulses traveling therethrough that compensates for the OPL difference. This allows for drastically relaxed tolerances when making the loops, leading to easier and more cost-effective manufacturing of the interferometer as well as related devices such as a optical-fiber-based QKD system.