The temperature dependence and fluctuation behaviour of the birefringences of two non-polarization-preserving fibers have been investigated experimentally at approximately 1 m long fiber pieces. The linear ret8rdance of one of the fibers drops to one half, when the fiber is warmed up from 20 to 50o C, whereas the other fiber shows a much lower temperature dependence. Without intentional temperature variations the linear birefringence of both fibers show fluctuations with nearly equal rms amplitude values of 2 to 3 mrad but different speed at room temperature. The influence of temperature, fiber twisting and fiber length on the fluctuations is considered.
"Temporal Birefringence Fluctuations Observed In Some Single-Mode Fibers", Proc. SPIE 0478, Fiber Optic and Laser Sensors II, (17 September 1984); doi: 10.1117/12.942665; https://doi.org/10.1117/12.942665