Wavelength division multiplexing optical transmission system

A wavelength division multiplexing optical transmission system, comprising:

• an optical transmission line which has a first transmission segment formed by linking together a first optical fiber having positive wavelength dispersion relative to a signal light wavelength and a relatively large nonlinear effective area, and a second optical fiber having negative wavelength dispersion relative to a signal light wavelength and a relatively small nonlinear effective area;
• and
• an optical amplification unit for amplifying wavelength division multiplexed signal light being propagated over said optical transmission line,
• wherein said wavelength division multiplexed signal light input to said optical transmission line is propagated successively over said first optical fiber and second optical fiber of said first transmission segment, and then sent to said optical amplification unit,
• said wavelength division multiplexing optical transmission system further comprising:
• a wavelength dispersion applying means for applying a preset negative wavelength dispersion to said wavelength division multiplexed signal light input to said optical transmission line.

A wavelength division multiplexing optical transmission system, comprising:

• an optical transmission line having a plurality of first transmission segments, each of which is formed by linking together a first optical fiber having positive wavelength dispersion relative to a signal light wavelength and a relatively larger nonlinear effective area, and a second optical fiber having negative wavelength dispersion relative to a signal light wavelength and a relatively small nonlinear effective area, and a second transmission segment formed with a third optical fiber having wavelength dispersion capable of compensating negative cumulative wavelength dispersion generated in said preset number of first transmission segments;
• and
• an optical amplification unit for amplifying wavelength division multiplexed signal light being propagated over said optical transmission line,
• wherein said wavelength division multiplexed signal light input to said optical transmission line is propagated successively over said first optical fiber and second optical fiber of each of said first transmission segments, and then sent to said optical amplification unit;
• and said wavelength division multiplexed signal light is propagated over said preset number of first transmission segments, and then sent to said second transmission segment;
• and
• wherein said optical transmission line is set so that the magnitude of compensation in said second transmission segment will be insufficient for negative cumulative wavelength dispersion generated in said preset number of first transmission segments.

An optical transmission line for optical communication, comprising:

• a first optical fiber having a positive wavelength dispersion value and positive wavelength dispersion-slope relative to a transmitted signal light;
• and
• a second optical fiber having a negative wavelength dispersion value and negative wavelength dispersion-slope relative to a transmitted signal light, said first and second optical fiber, linked together, forms a transmission segment of said optical transmission line,
• wherein a ratio of the length of said second optical fiber to the entirety of the length of said transmission segment is from 20 to 40%, and wherein said transmitted signal light is propagated over in order of said first optical fiber and second optical fiber.