| 摘要 |
PROBLEM TO BE SOLVED: To obtain a semiconductor laser output control device which can control adequately a laser light injected in an optical amplifier, corresponding to the number of channels of an optical signal, and an optical signal transmission system. SOLUTION: An optical signal outputted from a first transmitter 201 to an optical fiber up-transmission line 203 is inputted in a first erbium doped fiber 212, amplified by a backward excitation system, with a laser light outputted from a first pumping light output part 216, and sent out to a first receiver 202. An optical fiber down-transmission line has the same constitution. When the number of channels of the optical signal transmitted through the up-transmission line 203 changes, the first pumping light output part 216 changes the output level of a semiconductor laser which is outputted from the output part 216, corresponding to the change. Thereby the output of each channel of the optical signal after amplification can be maintained to be constant when the number of channels is increased or decreased. |
