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. 15, 2011
Filed:
Jul. 20, 2007
Harry Vig, North Billerica, MA (US);
Harry Vig, North Billerica, MA (US);
MagiQ Technologies, Inc., Somerville, MA (US);
Abstract
A QKD system () having two QKD stations (Alice and Bob) optically coupled by an optical fiber link (FL), wherein Bob includes a variable timing delay arranged between Bob's controller (CB) and modulator (MB) or detector unit (). A set-up and calibration procedure is performed wherein delay DLis adjusted until the timings for the modulator and detector unit (Tand T, respectively) are established. Delay DLis then fixed so that the detector unit and modulator operate in a common timing mode that is not changed if the synchronization signal is changed. The timing Tof the synchronization (sync) signals (SS) sent from Alice to Bob is adjusted to arrive at optimum system performance. Once the QKD system is in operation, because the sync signal can drift, the sync signal timing Tis dithered maintain optimum QKD system performance. Since the modulator and detector unit timing is tied together, dithering the sync signal also dithers the modulator and detector unit together in a 'common mode,' rather than varying the timing of each of these elements separately.