| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress PDG that becomes one of the causes of the degradation in transmission characteristics of a Raman amplifier. SOLUTION: In the amplifier, the transmission loss of signal light beams propagated through a transmission path is compensated for by a Raman amplification effect of stimulated light beams inputted to the path from a stimulating light source. The source is provided with a semiconductor laser which outputs light, a polarization holding fiber which propagates the outputted light of the laser for longer than a prescribed length in two polarization modes that have a propagation constant difference and are mutually orthogonal and a stimulated light source outputting port which outputs the output light propagated through the fiber as stimulated light to be inputted to the transmission path.</p> |
