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:
Aug. 03, 2004
Filed:
Apr. 28, 2003
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 6/28 ; H04B 1/000 ; H04B 1/012 ;
U.S. Cl.
CPC ...
G02B 6/28 ; H04B 1/000 ; H04B 1/012 ;
Abstract
The objective is an optical transmission unit capable of coupling and branching signal lights of individual wavelengths at a data rate of 10 Gbits/s. In order to achieve the objective, DCFs are provided and proper values of dispersion compensation are given, so that different characteristics depending on the respective wavelengths to be coupled, split and pass through without being split are obtained. The signal lights are amplified by a plurality of low-excitation optical amplifiers to regain their light levels which are weakened due to using an optical coupler, branching filter and DCF together, thereby enabling a long-distance transmission.