Device for measuring bent shape of optical fiber and method for measuring bent shape thereof

摘要

PROBLEM TO BE SOLVED: To provide an optical fiber bent shape measurement device and method with which it is possible to reduce the effect of crosstalk between cores and suppress degradation in stain measurement sensitivity, and to perform long distance measurement and seamless distribution measurement.SOLUTION: The optical fiber bent shape measurement device comprises: an analyzer 20 for directing the same pump light and different probe lights into cores C1-C4 of an optical fiber sensor head MCF having different Brillouin frequency shift amounts BFS1-BFS4; and optical receivers 21-24 for measuring the longitudinal distribution of the shift amounts BFS1-BFS4 in the optical fiber sensor head MCF, finding the strain amounts ε1-ε4 of the cores C1-C4 at each point from the shift amounts BFS1-BFS4 at each point, and finding curvature distribution and the direction of curvature at each point from a strain angle θ formed by a line linking the center of bend C and the center of cross section of the optical fiber sensor head MCF and a line linking the discretionary core center and center of the cross section of the optical fiber sensor head MCF, the strain amounts ε1-ε4, and the bend radius r of the optical fiber sensor head MCF.SELECTED DRAWING: Figure 1