Mathematical simulation of random coupling of polarization modes in single-mode optical fibers: III. Optimization of parameters of a depolarizer of polychromatic radiation for a fiber ring interferometer

Based on the model of random inhomogeneities in a single-mode optical fiber (SOF) suggested earlier, the effect of the ratio of lengths of sections of a Lyot depolarizer of polychromatic radiation located at the entrance to a fiber ring interferometer (FRI) on the fading and zero drift of the interference signal at the FRI output is considered by the method of mathematical simulation. It is shown that, when the ratio of lengths of sections of the Lyot depolarizer is 1 : 2, small temperature variations of this ratio can result in significant periodic variations in the intensity of the interference signal. When the depolarizer of polychromatic radiation with the ratio of lengths of sections equal to 1 : 3 is used (the difference between the length of the second section and the doubled length of the first section should be much greater than the radiation depolarization length in the SOF of the depolarizer), variations in this ratio do not affect parameters of the FRI.