Characterization of Brillouin Gain Spectra in Polymer Optical Fibers Fabricated by Different Manufacturers at 1.32 and 1.55 $\mu{\rm m}$

We characterize the Brillouin gain spectra (BGS) in perfluorinated graded-index polymer optical fibers (PFGI-POFs) at 1.32 μm and 1.55 μm. Three kinds of PFGI-POFs with the same core diameter, but which are fabricated by different manufacturers, are tested. For all the PFGI-POFs, the Stokes power measured at 1.32 μm is higher than that at 1.55 μm due to the lower propagation loss, but significant differences in Stokes power are observed among the three. Based on the measurement obtained by the optical time-domain reflectometry, we show that the actual propagation loss of the PFGI-POFs plays a crucial role in observing BGS.