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:
Jul. 24, 2007
Filed:
Jul. 16, 2004
Applicants:
Taizo Maeda, Kawasaki, JP;
Takehiro Fujita, Kawasaki, JP;
Motoyoshi Sekiya, Kawasaki, JP;
Inventors:
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04B 10/16 (2006.01);
U.S. Cl.
CPC ...
Abstract
Conventionally, an adjustment of an optical power level of an input Pin of an optical amplifier module is made with an optical variable attenuator. An optical coupler for measuring the optical power level of Pin and an optical variable attenuator are replaced by a variable optical coupler. The branch ratio of the variable optical coupler is varied, whereby the input optical power level Pin to an optical amplifier module is adjusted. As a result, an optical loss is reduced by an amount corresponding to the elimination of the optical attenuator, and also the OSNR of the optical amplifier module is improved.