MEASURING APPARATUS FOR MEASURING RESIDUAL STRESS AND PHOTOELASTIC EFFECT OF OPTICAL FIBER, AND METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for measuring residual stresses and photoelastic effects of optical fibers. SOLUTION: There are included a light source, a rotating optical diffusing device, an optical condenser, a polariscope for making the light passing the optical collector to be polarized to beams linearly polarized by 45 deg. with respect to an axis of the optical fiber, a polarization analyzer set at 90 deg. with respect to the polariscope for preventing a background image of the optical fiber, to which the optical fiber is adhered from passing, an optical fiber-pulling device having a tension sensor for measuring a tension applied to the optical fiber, by making the optical fiber positioned at the polarization analysis device pulled in the length direction, an objective lens for enlarging an image of the light passing the optical fiber, and a CCD array for measuring the transmission change of the optical fiber, in accordance with the tension applied to the optical fiber by the optical fiber-pulling device by tracking diametrical spots of the optical fiber.