Patent ID: 7336869
Filing Date: 2008-02-26
Classification: H01S,H04B,H04J

Abstract:
1. An unrepeatered optical communication system comprising: a first end terminal of an unrepeatered optical communication system coupled to a first end of a first transmission fiber, the first end terminal adapted to generate an optical signal and a first pump signal for receipt by the first transmission fiber, wherein the first pump signal co-propagates with at least a portion of the optical signal within at least a portion of the first transmission fiber, wherein the first pump signal operates to amplify the optical signal in the first transmission fiber through Raman amplification; a remote optically pumped amplifier (ROPA) coupled to a second end of the first transmission fiber and to a first end of a second transmission fiber, the ROPA operable to receive the optical signal from the first end terminal of the unrepeatered communication system, the ROPA comprising a rare-earth doped optical fiber, the optical signal comprising a plurality of optical signal wavelengths within a 1567-1620 nanometer wavelength range; and a second end terminal coupled to a second end of the second transmission fiber, the second end terminal adapted to receive the optical signal and generate a second pump signal, wherein the second pump signal counter-propagates with the optical signal within at least a portion of the second transmission fiber, the at least a portion of the second transmission fiber comprising a distributed Raman amplifier operable to amplify the optical signal through Raman amplification, the second pump signal comprising at least one pump signal wavelength operable to excite the rare-earth doped fiber and a power level, wherein the ROPA introduces a loss of no more than four (4) decibels to the optical signal.