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. 29, 2005
Filed:
Aug. 28, 2000
Kazuyoshi Yamaki, Yokohama, JP;
Hideyuki Serizawa, Nagano, JP;
Kazuyoshi Yamaki, Yokohama, JP;
Hideyuki Serizawa, Nagano, JP;
Opnext Japan, Inc., Yokohama, JP;
Abstract
In the application of the optical transmitter to any system for the compensation of passing degradation, the invention provides the optical transmitter which maintains constant modulator output and the highly reliable optical transmission by tuning, the alpha parameter for given systems. As the optical element back-face output power detected by PDdepends on the optical element driving current amount, the electronic absorption amount of the EA optical modulator monitored by the electronic absorption monitor depends on the optical output of the optical elementand the EA optical modulator driving point of the driving part. It is possible to detect a change in the driving point in the EA optical modulator by taking a difference between the amount monitored by the PDand the amount monitored by the electronic absorption monitor. Consequently by applying to the driving current sourcethe current corresponding to the change of the EA optical modulator driving point, it is possible to automatically compensate the modulator outputwhen the driving point of the EA optical modulator changes due to the change of the alpha parameter and the passing degradation.