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:
Apr. 30, 2002
Filed:
Dec. 15, 1997
David J. Xu, Sunnyvale, CA (US);
Sami T. Hendow, Sunnyvale, CA (US);
Ditech Corporation, Mountain View, CA (US);
Abstract
A four-port Wavelength-Division-Multiplexing (WDM) element is disclosed that can be employed for various purposes in optical communication networks, particularly in bi-directional fiber optic lines. In one embodiment, one four-port WDM element is used with one optical amplifier to provide bi-directional propagation on the same fiber. In another embodiment, the four-port element is used in conjunction with optical attenuators to provide for gain equalization of channels and the flexibility to add or remove channels. In yet another embodiment, input and output ports are added to current-art elements thereby enabling bi-directional operation to be achieved with equipment that does not provide such capabilities.