METHOD FOR MEASURING STRUCTURE OF OPTICAL FIBER

摘要

PURPOSE:To perform highly accurate measurement, by allowing the optical axis connecting a light source and an image pickup system to cross the longitudinal direction of an optical fiber. CONSTITUTION:The optical axis 2 connecting the light source 1 and an image pickup system consisting of an image pickup lens 4 and a TV camera 5 is allowed to cross the longitudinal direction of an optical fiber 3 to be inspected at a right angle and arranged at the position passing the center of the fiber 3 to be inspected. Then, the fiber 3 to be inspected is rotated around the axis thereof by a fiber setting stage 6 equipped with a rotary mechanism or rotated thereby so that the optical axis passes the measuring point on the fiber 3 to be inspected and crosses the axis of the fiber 3 to be inspected at a right angle. The relative positions of the clad outer edge part of the fiber 3 to be inspected and core-clad boundary part thereof at least at two or more angles of rotation at the time of rotation are confirmed and the correction of the lens effect on the surface of the fiber 3 to be inspected is performed on the basis of the positional data of an observation surface and the real position of the core-clad boundary part at an observation angle is calculated to make it possible to simply measure the structural parameter of the fiber to be inspected with high accuracy without cutting the fiber to be inspected.