| 摘要 |
PURPOSE:To make the inversion distribution in an optical fiber uniform in all areas and to eliminate unnecessary gain saturation and deterioration in a noise index by inserting a rare eatch dope optical fiber into the optical path of a Fabry-Perot type laser or a ring laser. CONSTITUTION:When an optical multiplexer installed between one end face of an optical amplifier 7 and one end face of an optical fiber 1 inputs a signal light which is emitted from a signal light generation light source 3 and propagated and an exciting light emitted from the amplifier 7 to one input terminal and the other terminal, respectively in order to multiplex optically the exciting light for exciting the optical fiber 1 being the emission of a traveling-wave type optical amplifier 7 having the gain in the vicinity of absorption wavelength of the rare earth dope optical fiber 1, and the signal light, an optically multiplexed light is outputted so as to be coupled to the optical fiber 1 from one output terminal. In this case, since the optical multiplexer 4 and an optical fiber 5 are provided in the optical path, the oscillation by other wavelength than exciting wavelength is suppressed. |
