Abstract: A method for pumping remote optically-pumped fiber amplifiers (ROPAs) in fiber-optic telecommunication systems is disclosed which uses cascaded Raman amplification to increase the maximum amount of pump power that can be delivered to the ROPA. According to the prior art, high power at the ROPA pump wavelength, ?p, is launched directly into the fiber and the maximum launch power is limited by the onset of pump depletion by Raman noise and oscillations due to the high Raman gain at ˜(?p+100) nm. In preferred embodiments of the present invention, a ‘primary’ pump source of wavelength shorter than ?p is launched into the delivery fiber along with two or more significantly lower-power ‘seed’ sources, among which is included one at ?p. The wavelength and power of the seed source(s) are chosen such that, when combined with the high-power primary source, a series, n, where n?2, of Raman conversions within the fiber ultimately leads to the development of high power at ?p.

Abstract: A method for pumping remote optically-pumped fiber amplifiers (ROPAs) in fiber-optic telecommunication systems is disclosed which uses cascaded Raman amplification to increase the maximum amount of pump power that can be delivered to the ROPA. According to the prior art, high power at the ROPA pump wavelength, ?p, is launched directly into the fiber and the maximum launch power is limited by the onset of pump depletion by Raman noise and oscillations due to the high Raman gain at ˜(?p+100) nm. In preferred embodiments of the present invention, a ‘primary’ pump source of wavelength shorter than ?p is launched into the delivery fiber along with two or more significantly lower-power ‘seed’ sources, among which is included one at ?p. The wavelength and power of the seed source(s) are chosen such that, when combined with the high-power primary source, a series, n, where n?2, of Raman conversions within the fiber ultimately leads to the development of high power at ?p.

Abstract: A pumping scheme for distributed Raman amplification (DRA) in optical fiber telecommunication systems is disclosed in which pump energy at the wavelength(s) required for DRA of the transmitted optical signal(s) is developed within the transmission fiber through a series, n, where n≧1, of Raman conversions. In preferred embodiments, a ‘primary’ pump source of wavelength shorter than the ultimately desired pump wavelength(s) is launched into the fiber along with one or more significantly lower-power secondary ‘seed’ sources. The wavelength and power of the secondary source(s) are chosen such that, when combined with the high-power primary source, Raman conversions within the fiber ultimately lead to the development of high power at the desired pump wavelength(s).

Abstract: A pumping scheme for distributed Raman amplification (DRA) in optical fiber telecommunication systems is disclosed in which pump energy at the wavelength(s) required for DRA of the transmitted optical signal(s) is developed within the transmission fiber through a series, n, where n≧1, of Raman conversions. In preferred embodiments, a ‘primary’ pump source of wavelength shorter than the ultimately desired pump wavelength(s) is launched into the fiber along with one or more significantly lower-power secondary ‘seed’ sources. The wavelength and power of the secondary source(s) are chosen such that, when combined with the high-power primary source, Raman conversions within the fiber ultimately lead to the development of high power at the desired pump wavelength(s).