Backscattering measurement of bending-induced birefringence in single mode fibres

The local distribution of birefringence in a very low birefringence single mode fibre less than 1 km long is measured by analysing the backscattered light. The experimental results of bending-induced birefringence measurements for various bending radii are in good agreement with those calculated. For 130 ¿m diameter fibre wound around cylinders of radii 15 cm and 8 cm, the bending-induced birefringence ßb(15 cm)=9°/m and ßb(8 cm)=34°/m, respectively, at ¿=904 nm.