Optimized polarization state for self-heterodyne-based Brillouin measurement in plastic optical fibers

The state of polarization (SOP) is generally adjusted to optimize the signal-to-noise ratio of Brillouin measurement based on self-heterodyne detection. Although Brillouin Stokes power in silica fibers is known to be enhanced by optimizing the SOP, the role of SOP optimization in plastic optical fibers (POFs) is quite different from that in silica fibers. In this study, we experimentally clarify that the role of SOP optimization in POFs lies not in enhancing the Brillouin Stokes power but in suppressing the tail of the Rayleigh-scattered light spectrum.