Mathematical modeling of random coupling between polarization modes in single-mode optical fibers: XI. Dependence of the zero drift of fiber ring interferometers on the interval of temperature variation of the fiber

The dependence of the value of the zero drift of a fiber ring interferometer (FRI), which is caused by a change in polarization nonreciprocity as a consequence of a change in the random coupling of polarization modes at inhomogeneities of the FRI loop, on the value of the interval of possible temperature variation of the single-mode optical fiber (SMF) of the FRI loop is considered. It is shown that the value of the zero drift of an FRI with a nonmonochromatic radiation source—a superluminescent diode—in a rather broad interval of temperature variations (about 100 K) is proportional to the value of the interval itself and inversely proportional to the linewidth of the radiation source. Numerical estimations are made, and they show that, for practical values of the interval of temperature variation in a room, the value of the zero drift may be much smaller than the values calculated according to the method of averaging over independent realizations of random inhomogeneities in the SMF of an FRI loop. When temperature stabilization is used, the value of the zero drift of an FRI can be additionally reduced by one to two orders of magnitude.