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. 31, 1990
Filed:
Jul. 21, 1989
Syuji Suzuki, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An optical wavelength-division multiplex transmission system having an optical filter (100) for filtering spontaneous emission noise from an optically multiplexed signal which has been amplified by an optical amplifier (622), which can be a laser amplifier or a fiber Raman amplifier. The output signal from the optical filter may be further amplified by a second optical amplifier (624), and the second amplified signal may be sent to a further optical filter. The optical filter includes an optical demultiplexer and an optical multiplexer, and can be a Fabry-Perot interferometer or a Mach-Zehnder interferometer. The optical filter is for transmitting pass-bands with center wavelengths corresponding to those of the wavelengths of the optical signals to be transmitted by the optical wavelength-division wavelength multiplex transmission system.