Optical fiber, optical component, dispersion compensating fiber module, and optical communication system

A dispersion compensating fiber module which compensates for a chromatic dispersion of an optical transmission line through which signal light propagates, comprising:

• an input terminal for receiving the signal light;
• an output terminal for outputting the signal light;
• a dispersion compensating optical fiber disposed on an optical path between said input terminal and said output terminal, said dispersion compensating optical fiber having a chromatic dispersion whose sign is opposite to that of the chromatic dispersion of said optical transmission line in a signal wavelength band;
• and
• a Raman amplification optical fiber disposed on the optical path between said input terminal and said output terminal, said Raman amplification optical fiber having the following characteristics of:
• an FOM Raman of 8 (1/dB/W) or more with respect to signal light having a wavelength of 1,650 nm when pumping light having a wavelength of 1,550 nm is supplied, and
• a chromatic dispersion having an absolute value of ½ or less that of said dispersion compensating optical fiber at the wavelength of 1,650 nm and 10 ps/nm/km to 50 ps/nm/km.

An optical communication system comprising:

• an optical transmission line for transmitting signal light;
• and
• a dispersion compensating fiber module for compensating for a chromatic dispersion in said optical transmission line, said dispersion compensating fiber module including:
• a case having a first connector for receiving the signal light from the optical transmission line, and a second connector for sending out the signal light to the optical transmission line, and
• a dispersion compensating optical fiber which is housed in said case and has a chromatic dispersion whose sign is opposite to that of the chromatic dispersion of said optical transmission line, said dispersion compensating optical fiber having one end optically coupled to said first connector, and the other end to which a third connector is attached,
• said second and third connectors having structures that allow said connectors to be directly coupled to each other and optically connected to each other via a Raman amplification optical fiber.