Patent ID: 6490078
Filing Date: 2002-12-03
Classification: H01S

Abstract:
An optical fiber for an optical amplifier for amplifying signals propagating therethrough by using pumping light supplied thereto, said optical fiber for optical amplifier comprising:a core region extending along a predetermined axis and having a first refractive index, said core region having a structure ensuring a single mode with respect to said signals and at least a part doped with an element for signal amplification; an inner cladding region provided on the periphery of said core region, and having a second refractive index lower than said first refractive index, said inner cladding region having a structure ensuring a multi-mode with respect to said pumping light; an outer cladding region provided on the periphery of said inner cladding region and having a third refractive index lower than said second refractive index; and one or more mode coupling gratings passing core mode signals therethrough, and inducing a mode coupling between an inner cladding mode and a core mode with respect to said pumping light.