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. 04, 2008
Filed:
Feb. 23, 2006
J. Howell Mitchell, Jr., Amherst, NH (US);
Harry Vig, North Billerica, MA (US);
Michael J. Lagasse, Nahant, MA (US);
J. Howell Mitchell, Jr., Amherst, NH (US);
Harry Vig, North Billerica, MA (US);
Michael J. LaGasse, Nahant, MA (US);
Magiq Technologies, Inc, New York, NY (US);
Abstract
A cascaded modulator system () and method for a QKD system () is disclosed. The modulator system includes to modulators (Mand M) optically coupled in series. A parallel shift register () generates two-bit (i.e., binary) voltages (L, L). These voltage levels are adjusted by respective voltage adjusters (-and-) to generate weighted voltages (V, V) that drive the respective modulators. An electronic delay element () that matches the optical delay between modulators provides for modulator timing (gating). The net modulation (M) imparted to an optical signal () is the sum of the modulations imparted by the modulators. The modulator system provides four possible net modulations based only on binary voltage signals. This makes for faster and more efficient modulation in QKD systems and related optical systems when compared to using quad-level voltage signals to drive a single modulator.