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:
Jan. 05, 2010
Filed:
Nov. 13, 2006
Tomoaki Takeyama, Kawasaki, JP;
Keiko Sasaki, Kawasaki, JP;
Shinichirou Muro, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical amplifier of the present invention comprises: first and second optical amplifying sections connected in series to each other between an input port and an output port; a first variable optical attenuator arranged on a former stage of the first optical amplifying section; a second variable optical attenuator arranged between the first and second optical amplifying sections; an optical amplification control section that controls the first and second optical amplifying sections; and an optical attenuation control section that controls the first and second variable optical attenuators. The optical amplification control section controls each of the optical amplifying sections so that a gain of the entirety of the optical amplifier is held constant, and the optical attenuation control section controls attenuation amounts of the variable optical attenuators so that monitor values of the output powers from the variable optical attenuators approximate the same value, provided that a value of the sum of the attenuation amounts of the variable optical attenuators decided according to the signal light input power per one wavelength of a WDM light is held constant. As a result, it becomes possible to provide at a low cost the optical amplifier capable of achieving flat output wavelength characteristics and the favorable NF, irrespective of the signal light input power per one wavelength of the WDM light and the number of wavelengths thereof.