Wavelength division multiplex communication link for optical transmission

A wavelength division multiplex communication link of an optical transmission system for compensating dispersion at a 1550 nm optical transmission wavelength band comprising:

• a dispersion compensating fiber coupled to a single mode fiber of an 1300 nm band zero dispersion of a single mode fiber network having zero dispersion at a 1300 nm optical transmission wavelength band, wherein a dispersion compensating fiber has a line length L.sub.DCF substantially satisfying a condition D.sub.SMF .times.L.sub.SMF /.vertline.D.sub.DCF .vertline.=L.sub.DCF and wherein the dispersion slope at a 1550 nm wavelength band of said single mode fiber is S.sub.SMF, the dispersion value thereof is D.sub.SMF, and line length is L.sub.SMF, and the dispersion slope at a 1550 nm wavelength band of said dispersion compensating fiber is S.sub.DCF, dispersion value thereof is D.sub.DCF, and line length is L.sub.DCF, and a dispersion shift fiber in which the dispersion slope at a 1550 nm wavelength band is S.sub.DSF and the dispersion thereof is made substantially zero is further connected thereto with a line length L.sub.DCF substantially satisfying a condition of S.sub.SMF .times.L.sub.SMF +S.sub.DCF .times.L.sub.DCF +S.sub.DSF .times.L.sub.DSF =0.

A wavelength division multiplex communication link of an optical transmission system for compensating dispersion of an optical transmission at a wavelength band of about 1550 nm comprising:

• a dispersion compensating fiber having a negative dispersion value at a wavelength band of 1550 nm;
• a single mode optical fiber of a single mode fiber network having zero dispersion at a wavelength of 1300 nm with a line length which compensates the dispersion slope of the single mode fiber to substantially zero, coupled with the disperson compensating fiber;
• and, a dispersion flat fiber for providing substantially zero dispersion slope when connected thereto, with a line length which makes the remaining dispersion value substantially zero, to the terminal end of a connection link of the single mode fiber and dispersion compensating fiber, whereby both the dispersion slope of a single mode fiber and dispersion value thereof are adjusted to be substantially zero at the terminal end of the dispersion flat fiber.