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:
Mar. 25, 2003
Filed:
Nov. 13, 2000
James Allan Wilkerson, Jr., Satellite Beach, FL (US);
James Vincent Wernlund, Indialantic, FL (US);
Alen Fejzuli, Palm Bay, FL (US);
Stephen Philip Reddy, Melbourne, FL (US);
JDS Uniphase Corporation, San Jose, CA (US);
Abstract
A single reference tone/frequency-based control scheme adjusts the DC bias voltage and modulation signal drive level to an external X-cut lithium niobate Mach Zehnder modulator, in accordance with phase quadrature components of the output of the single tone frequency generator. A pair of phase quadrature feedback loops are coupled through a loop filter of a common feedback path electo-optically coupled to monitor the optical output of the laser modulator. Quadrature-phase (Q) and in-phase (I) frequency components are respectively coupled to respective Q and I channel phase detectors, coupled to synchronous demodulators for the Q and I channel feedback loops. The phase detectors produce respective error voltages that close Q and I channel feedback loops and control the optical extinction ratio and DC bias voltage of the modulator.