POLARIMETRIC ANALYSIS OF 2-MODE, ELLIPTIC-CORE OPTICAL FIBERS

We show that linearly polarized light launched at different angles with respect to the major axis of a two-mode, elliptical-core fiber results in an amplitude-modulated beat-length pattern in the far field. The variation of the output pattern is explained theoretically and confirmed experimentally. A polarizer placed at the output of the fiber is shown to eliminate the amplitude modulation in the output signal. A simple theoretical model, based on the weakly guiding assumption, is shown to be helpful in determining few-mode fiber sensor parameters in practical systems.