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:
Apr. 29, 2003
Filed:
Feb. 13, 2002
Dennis S. Olesen, Skiby, DK;
Tellabs Denmark A/S, Ballerup, DK;
Abstract
The invention relates to a method and a modulator circuit for modulating light in a modulator circuit. The modulator circuit comprises a Mach-Zehnder modulator having at least one optical input and at least one optical output, said Mach-Zehnder modulator modulating light, which is fed to the input of the Mach-Zehnder modulator in response to applied electrical modulation signals from a driver circuit. According to a method of the invention, the applied modulation signal on the electrodes of the Mach-Zehnder modulator is superimposed by a pilot tone which is thus superimposed by the modulated light emitted by the Mach-Zehnder modulator. In response to the emitted modulated light, an electrical feedback circuit generates bias control signals for the bias circuit and driver control signals for the driver circuit for regulating the bias signal and the driver signal fed to the Mach-Zehnder modulator.