METHOD FOR ESTIMATING CONNECTION LOSS AT CONNECTIONS OF DIFFERENT-DIAMETER CORE FIBER AND METHOD FOR CONNECTING DIFFERENT-DIAMETER CORE FIBER

摘要

PROBLEM TO BE SOLVED: To provide a method for accurately and simply estimating a connection loss at the connections of a different-diameter core optical fiber regardless of environmental changes, etc. ;SOLUTION: A light source 1 is arranged at a distance from an optical fiber 3. On the side opposite to the fight source, the optical fiber 3 is irradiated with transmission light, for example, from the direction of the x-axis orthogonal to the optical axis Z of the optical fiber 3, and a microscope lens 9 forms an image in an image pickup camera 6 by the light transmitted through the optical fiber 3 to obtain the transmitted-light image of the optical fiber 3. With the contrast between the core-parts of the transmitted-light images before and after the fusion connection of the optical fiber 3 as parameters, the computation data of a connection loss due to core dopant diffusion and the computation data of a connection loss due to mode field diameter difference are obtained in advance. Then the contrast between the core parts of the transmitted-light images before and after the fusion connection of the optical fiber 3 is measured. On the basis of the measurement data and the above-mentioned computation data, the above-mentioned connection losses are each obtained, and the total of both connection losses are taken as the total connection loss of the optical fiber.;COPYRIGHT: (C)2000,JPO