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:
May. 31, 2005
Filed:
Oct. 02, 2000
Balakrishnan Sridhar, Ellicott City, MD (US);
Clark Scrandis, Columbia, MD (US);
James E. Degrange, Jr., Glen Burnie, MD (US);
Michael G. Taylor, Laurel, MD (US);
Jun Bao, Ellicott City, MD (US);
Balakrishnan Sridhar, Ellicott City, MD (US);
Clark Scrandis, Columbia, MD (US);
James E. DeGrange, Jr., Glen Burnie, MD (US);
Michael G. Taylor, Laurel, MD (US);
Jun Bao, Ellicott City, MD (US);
CIENA Corporation, Linthicum, MD (US);
Abstract
A three stage optical amplifier is disclosed having a substantially flat gain profile. The amplifier includes a variable optical attenuator coupled between second and third stages of the amplifier and a dispersion compensating element. The attenuation of the optical attenuator is adjusted in accordance with the loss across dispersion compensating element and the optical power input to the amplifier to thereby obtain a substantially flattened gain profile. An offset value can also be used to refine the variable optical attenuator control and minimize nonflatness. The first and second stages are preferably pumped to provide high gain and a low noise figure and the third stage is preferably pumped to provide a high optical conversion efficiency. In an additional example, received optical powers associated with each of the channels in a WDM system are monitored and the attenuators within each amplifier in the system are controlled so that the received powers are substantially equal.