| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an optical amplifier for controlling gain saturation caused by generation of Stokes rays of 2nd order or higher. SOLUTION: By arranging a filter 7 for cutting off Stokes rays of 2nd order or higher between optical fibers 3a and 3b for a Raman amplifier, the Stokes rays of 2nd order or higher generated from the optical fiber 3a for the Raman amplifier are prevented from being propagated into the optical fiber 3b for the Raman amplifier.</p> |
