Determination of the individual strain-optic coefficients in single-mode optical fibres

A method to determine the individual strain-optic coefficients in single-mode fibers is described. It is based on two photoelastic experiments, namely, the polarimetric measurement of optical activity induced by mechanical twist and the interferometric measurement of optical-path-length change induced by static longitudinal strain. For fibers with pure silica core and B/sub 2/O/sub 3/ doped cladding, the optical activity per unit twist rate and the phase change per unit fiber elongation have been measured to be 0.1472 and 1.150*10/sup 7/ rad/m, respectively. The strain-optic coefficients have been measured to be p/sub 11/=0.113 and p/sub 12/=0.252, 7% lower than those of bulk silica.<
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