| 摘要 |
PROBLEM TO BE SOLVED: To provide a long distance optical wavelength division multiplexing transmission system, in which two-way communication can be carried out using distributed amplifiers in a single optical fiber while suppressing deterioration of transmission quality. SOLUTION: An uplink signal light and a downlink signal light are assigned with different bands (C-band and L-band), respectively. In a transmission line optical fiber 12, performing Raman amplification, the signal light of C-band is amplified by a pumping light from a pumping light source 14 for C-band, and the signal light of L-band is amplified by a pumping light from a pumping light source 10 for L-band. Since both the uplink signal light and the downlink signal light are amplified by backward pumping in Raman amplification, adverse effects of forward pumping to the signal light can be avoided. |
