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:
Feb. 29, 2000
Filed:
Jun. 04, 1997
Lucjan Sniadower, Paris, FR;
Pirelli Cavi e Sistemi S.p.A., Milan, IT;
Abstract
The present invention relates to an optical fiber telecommunications system and more in particular to an optical telecommunications system having a high loss transmission line. The optical fiber telecommunications system includes a transmission station producing at least one transmission signal in a predetermined wavelength band carrying the information, a receiving station for receiving said transmission optical signal, an optical fiber line connecting the transmission station and the receiving station, and at least one optical fiber amplifier connected along the line for amplifying the transmission optical signal, the amplifier having a total optical output power greater than 20 dBm. The fiber optic amplifier for amplifying a transmission signal including a first stage and a second stage, an isolator placed between the first stage and the second stage where the second stage includes an erbium doped fiber, pump means including two pump sources at different wavelengths in a second stage pump wavelength band, A WDM coupling means coupling the different wavelengths as a composite second stage pump signal, and a coupler coupling the composite second stage pump signal and the transmission optical signal to the erbium doped fiber.