Apparatus and method for measuring residual stress and photoelastic effect of optical fiber

摘要

Disclosed is an apparatus for measuring a residual stress and a photoelastic effect of an optical fiber (P), the apparatus comprising: a light source (102); a rotary type optical diffuser (104) distanced from said light source in a predetermined distance for suppressing a spatial coherence of a light radiated in the light source; an optical condenser (106) for condensing the radiated light passed through said optical diffuser (104) into a spot where the optical fiber (P) is located; a polariscope (108) for polarizing the light passed through said optical condenser (106) into a 45 DEG linear polarized light from an axis of the optical fiber (P); a polarization analyzer (110), installed at 90 DEG angle with said polariscope (108) and attached closely with the optical fiber (P), so as a background image of the optical fiber not to penetrate; an optical fiber strain unit including a strain sensor (122) for straining the optical fiber on said polarization analyzer (110) toward a longitudinal direction and measuring the strain; an object lens (112) for magnifying an image of the light penetrated through the optical fiber; and a charge coupled device (CCD) array (114) for measuring a penetration variation of the optical fiber caused from a strain by said optical fiber strain unit over the optical fiber (P) depending on each spots of the optical fiber diameter.