Influence of high hydrostatic pressure on beat length in highly birefringent single-mode bow tie fibers

New experimental studies on the effects of high hydrostatic pressure on highly birefringent optical fibers are presented. Using Rayleigh scattering, the effect of beat length modification in highly birefringent singlemode bow tie fibers under high pressure up to 100 MPa was investigated. The results indicate that the beat length decreases with pressure, with the mean coefficient of 1/L(B0)|dL(B)/dp| = 0.15%/MPa. A similar decrease of beat length was observed when uniaxial longitudinal stress was applied to the bow tie fiber. A more developed semiphenomenological interpretation of these experimental results is also presented in the paper.