Patent ID: 6817784
Filing Date: 2004-11-16
Classification: G02B

Abstract:
An optical fiber device comprising a first optical fiber and a second optical fiber having one end fusion-spliced to one end of said first optical fiber;wherein said first optical fiber has a first mode field diameter D1(L) at a position separated by a distance L from a fused point between said first and second optical fibers; wherein said second optical fiber has a second mode field diameter D2(L) at a position separated by said distance L from said fused point between said first and second optical fibers; wherein the minimum value D20 of said second mode field diameter is different from the minimum value D10 of said first mode field diameter; and wherein each of the maximum value of the ratio of change in said first mode field diameter (D1(L1)âˆ’D1(L2))/(L2âˆ’L1) between two points respectively separated by distances L1 and L2 (>L1) toward said first optical fiber from said fused point between said first and second optical fibers and the maximum value of the ratio of change in said second mode field diameter (D2(L1)âˆ’D2(L2))/(L2âˆ’L1) between two points respectively separated by said distances L1 and L2 (>L1) toward said second optical fiber from said fused point between said first and second optical fibers is 4.0 &mgr;m/mm or less.