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. 25, 1995
Filed:
Jul. 14, 1994
Yukinobu Nakabayashi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An optical fiber amplifier includes an optical amplifying section having an Er-doped fiber. A gain equalizing section is provided at secondary stage of the optical amplifying section and has an optical filter unit for compensating for wavelength dependency characteristics of a signal gain at the optical amplifying section. The gain equalizing section has a filter rotating device and the optical filter unit has et least two optical filters of transparent multi-layer film in which a layer of high refractive index and a layer of low refractive index are alternately and repeatedly stacked. The optical filter is rotated by the filter rotating device such that the wavelength transmission characteristics of the optical filter are set by changing an angle of incidence of the signal light with respect to the optical filter and the wavelength dependency characteristics of the signal gain are compensated for. The optical filter which is of the multi-layer film and which is rotatably arranged improves wavelength tunability.