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. 23, 1999
Filed:
Apr. 09, 1998
Jun Yu, Stittsville, CA;
Nortel Networks Corporation, Montreal, CA;
Abstract
A Mach-Zehnder optical modulator is provided having first and second modulation electrodes on respective first and second interferometric arms for receiving modulating electric fields, and the two modulation electrodes are of different lengths, the ratio of the lengths being designed to control the relative bias of the two arms, thereby provide for adjustment and optimization of frequency chirp, in a positive or negative chirp MZ modulator or in a configurable chirp MZ modulator. The modulator may have an asymmetric input y-junction coupler and an asymmetric output y-junction coupler to provide unequal power splitting, and interferometric arms defining two optical paths, which may be of equal or unequal length so as to generate a fixed phase difference of 0, .pi. or .pi./2. Preferably, the device is operated with equal push-pull drive, although non-equal push pull drive may alternatively be used. The asymmetric modulation electrodes may be used in combination with an additional control electrode or pair of control electrodes, and with equal or non-equal power splitting. This structure is applicable to either semiconductor MZ modulators or lithium niobate MZ modulators, and provides additional flexibility to optmize frequency chirp.