Analysis and measurement of birefringence in single-mode fibers using the backscattering method

The local parameters of linear, circular, and elliptical birefringence of backscattered light along a single-mode fiber are analyzed, and the twist-bending-induced elliptical birefringence in an extremely low birefringent single-mode fiber is measured using the backscattering method. The experimental results are in good agreement with the theoretical calculations. For a 130-microm-diameter fiber, twisted by 133 degrees /m and wound around a drum of 15-cm radius, the induced elliptical birefringence is |?| = 18 degrees /m at lambda = 904 nm.