Raman amplified optical system with reduction of four-wave mixing effects

An optical fiber for use in a Raman amplified optical transmission system, the transmission system comprising an information signal source for providing an input signal in a predetermined wavelength range of λs1-λs2 and utilizing a Raman amplification pump in a predetermined wavelength range of λp1-λp2, said fiber exhibiting a predetermined group-velocity dispersion controlled to reduce noise components in the region of Raman amplification by maintaining said predetermined group-velocity dispersion to exhibit a value that is either non-positive or greater than 1.5 ps/nm-km in the pump wavelength range λp1-λp2.

An optical fiber for use in a Raman amplified optical transmission system, the transmission system comprising an information signal source for providing an input signal in a predetermined wavelength range of λs1-λs2 and utilizing a Raman amplification pump in a predetermined wavelength range of λp1-λp2, said fiber exhibiting a predetermined zero-dispersion wavelength controlled to reduce four-wave mixing noise components in the region of Raman amplification by maintaining said zero dispersion frequency away from the average value of the pump frequency and the signal frequency.

A Raman amplified optical transmission system comprising an information signal source for providing an input signal in a predetermined wavelength range of λs1-λs2;

• an optical transmission fiber coupled to the output of the information signal source to provide for transmission of the optical signal to a predetermined location;
• and
• a Raman amplification pump coupled to said optical transmission fiber in a manner so as to generate Raman amplification of said input signal in said optical transmission fiber, said Raman pump source supplying a pump wave in a predetermined wavelength range of λp1-λp2, wherein said fiber exhibits a predetermined group-velocity dispersion and zero-dispersion wavelength controlled to reduce noise components in the region of Raman amplification by maintaining said predetermined group-velocity dispersion to exhibit a value that is either non-positive or greater than 1.5 ps/nm-km in the pump wavelength range λp1-λp2 and maintaining said zero-dispersion frequency away from the average value of the pump frequency and the signal frequency.

A Raman amplified optical transmission system comprising an information signal source for providing an input signal in a predetermined wavelength range of λs1-λs2;

• an optical transmission fiber coupled to the output of the information signal source to provide for transmission of the optical signal to a predetermined location;
• and
• a Raman amplification pump coupled to said optical transmission fiber in a manner so as to generate Raman amplification of said input signal in said optical transmission fiber, said Raman pump source supplying a pump wave in a predetermined wavelength range of λp1-λp2, wherein said fiber exhibits a predetermined group-velocity dispersion controlled to reduce noise components in the region of Raman amplification by maintaining said predetermined group-velocity dispersion to exhibit a value that is either non-positive or greater than 1.5 ps/nm-km in the pump wavelength range λp1-λp2.

A Raman amplified optical transmission system comprising an information signal source for providing an input signal in a predetermined wavelength range of λs1-λs2;

• an optical transmission fiber coupled to the output of the information signal source to provide for transmission of the optical signal to a predetermined location;
• and
• a Raman amplification pump source coupled to said optical transmission fiber in a manner so as to generate Raman amplification of said input signal in said optical transmission fiber, said Raman pump source supplying a pump wave in a predetermined wavelength range of λp1-λp2, wherein said fiber exhibits a predetermined zero-dispersion wavelength controlled to reduce four-wave mixing noise components in the region of Raman amplification by maintaining said zero-dispersion frequency away from the average value of the pump frequency and the signal frequency.