| 摘要 |
PURPOSE:To obtain this optical amplifier which has a high signal amplification gain by constituting an optical coupler so that large loss such as branching loss to signal light is not generated. CONSTITUTION:Exciting light is emitted as shown by an arrow 11 from an SLD module 6b for excitation which is driven by a super-luminescent diode(SLD) for excitation. Then the exciting light is guided by the optical coupler 8b to the core 13c of a rare earth doped double-core optical fiber 13a from the core 12c of an exciting light propagating multi-mode optical fiber 12a. The core 13b of the fiber 13a has a higher refractive index than the core 13c, so the exciting light is guided to the core 13b and absorbed to generate an inverted population inside. When signal light 3 corresponding to resonance wavelength is made incident on the core 13b, light which is equal in wavelength to and in phase with the signal light 3 is emitted. The intensity of the signal light 3 at the projection end of the fiber 13a is larger than that at the incidence end and the signal light 3 is amplified. |
