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. 09, 2002
Filed:
Nov. 17, 1998
Tadashi Koga, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A wavelength division multiplex transmission apparatus capable of transmitting a plurality of 1.55 micron band signal light of different wavelengths by multiplexing the wavelengths is disclosed. A plurality of dispersion compensation units are serially connected, and each executes dispersion compensation with a particular signal light and outputs a respective compensated light. Such signal light output from the dispersion compensation units are combined and then output to a transmission path. Monitor light lying in a 1.3 micron band not susceptible to the operation of an optical direct amplifier is input to the serially connected dispersion compensation units. In each dispersion compensation unit, a photo-detector detects the level of the monitor light. With this configuration, the apparatus is capable of surely detecting faults including the defective connector connection or the shutoff of an optical patch code between the dispersion compensation units.