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:
Oct. 19, 2004
Filed:
Sep. 24, 2001
Fujitsu Limited, Kawasaki, JP;
Abstract
A gain equalizer which equalizes gain versus wavelength characteristics of an optical amplifier. The gain versus wavelength characteristics of the optical amplifier include first, second and third gain peaks in a wavelength band with the second gain peak being between the first and third gain peaks. The optical amplifier amplifies an input signal in accordance with the gain versus wavelength characteristics to produce an output signal. The gain equalizer includes first, second and third optical filters having first, second and third transparency characteristics, respectively. The first, second and third transparency characteristics are periodic waveforms having different periods related to the wavelength difference between the first and third gain peaks. The second transparency characteristic is a periodic waveform having a period equal to 1/(2 ) of the period of the waveform of the first transparency characteristic. The third transparency characteristic is a periodic waveform having a period equal to ¼ of the period of the waveform of the first transparency characteristic. For example, the first transparency characteristic is a periodic waveform with ¼ period extending between the first and third gain peaks, the second transparency characteristic is a periodic waveform with one period extending between the first and third gain peaks, and the third transparency characteristic is a periodic waveform with two periods extending between the first and third gain peaks.