Method and apparatus for controlling raman amplification with a plurality of excitation light pulses which have a plurality of different wavelengths and are spaced with predetermined intervals

A Raman amplification control apparatus comprising:

• a pulsed excitation light generation unit which generates a plurality of excitation light pulses respectively having a plurality of different wavelengths;
• and
• an excitation control unit which controls output of said plurality of excitation light pulses from said Raman amplification control apparatus so that the plurality of excitation light pulses are output from said Raman amplification control apparatus in turn at such timings that the plurality of excitation light pulses do not overlap even after propagation of a predetermined effective length of predetermined optical transmission line.

A Raman amplified optical transmission system comprising:

• an optical transmission line;
• and
• an excitation control unit which is coupled to said optical transmission line, and injects into the optical transmission line a plurality of excitation light pulses having a plurality of different wavelengths.

A method for controlling Raman amplification, comprising the steps of:

• (a) generating a plurality of excitation light pulses respectively having a plurality of different wavelengths;
• and
• (b) injecting said plurality of excitation light pulses into a predetermined optical transmission line in turn.

A method for controlling Raman amplification, comprising the steps of:

• (a) generating a plurality of excitation light pulses respectively having a plurality of different wavelengths;
• and
• (b) injecting said plurality of excitation light pulses into a predetermined optical transmission line in turn at such timings that the plurality of excitation light pulses do not overlap even after propagation of a predetermined effective length of the predetermined optical transmission line.