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. 08, 2011
Filed:
Jan. 23, 2007
Steve S. Cho, Potomac, MD (US);
Cecil D. Smith, Woodbine, MD (US);
Steve S. Cho, Potomac, MD (US);
Cecil D. Smith, Woodbine, MD (US);
Ciena Corporation, Linthicum, MD (US);
Abstract
The present invention provides a software-based electro-optic modulator bias control system resident in an optical transceiver including an electro-optic modulator that includes an optical-to-electrical converter including a transimpedance amplifier, an analog-to-digital converter, and a software algorithm, wherein the software algorithm is operable for determining an optimum bias voltage applied to the electro-optic modulator by discovering a maximum average optical power transmitted by the electro-optic modulator, or quadrature point, wherein the quadrature point is discovered by determining at what bias voltage the slope of an average optical power transmitted by the electro-optic modulator, defined as an optical power change given an incremental bias voltage change, is equal to zero. The software-based electro-optic modulator bias control system also includes a control loop operable for determining if a radio frequency port of the electro-optic modulator is driven to a peak-to-peak voltage that is greater than (over-driven) or less than (under-driven) the peak-to-trough voltage of a response curve of the electro-optic modulator.