MULTI-WAVELENGTH COLLECTIVE OPTICAL AMPLIFIER CAPABLE OF COLLECTIVELY AMPLIFYING PLURAL WAVELENGTH SIGNALS

摘要

PROBLEM TO BE SOLVED: To collectively amplify multiple wavelength signals with an optical amplifier so that the gain of the amplifier can be controlled in a wider range of ≤1 dB by using an erbium-doped fiber having a cross section composed of a plurality of kinds of erbium-doped glass materials and a plurality of kinds of stimulating wavelength zones. ;SOLUTION: An erbium-doped fiber is constituted of a central GeO₂-SiO₂ glass material layer 41 and an Al₂O₃-SiO ring-like peripheral glass material layer 42. The mode field of 0.98μm band stimulating light in a refractive index distribution is narrower than that 44 of 12-48μm band stimulating light. Therefore, the 0.98μm band stimulating light can selectively stimulate the glass material layer 41 of the fiber and the 1.48μm band stimulating light can selectively stimulate the glass material layer 44. Consequently, the stimulating rates of the central part and ring-like part of the fiber can be controlled independently.;COPYRIGHT: (C)1997,JPO