| 摘要 |
PURPOSE:To obtain the optical amplifier which does not oscillate itself and has a high amplification degree. CONSTITUTION:An amplifier 12 generates natural emission light containing components with the same wavelength with input signal light and this natural emission light is inputted to a trailing-stage amplifier 13 having a high amplification degree at all times. Therefore, the amplifier 2 does not oscillate itself even when the signal light is not inputted to an input fiber 1. |
