A Determination of the Initial Level of the Brillouin Frequency Shift in Optical Fibers of Different Kinds

A dependence of the hyper-acoustic wave velocity on characteristics of the optical fiber core is analyzed in this paper. The values of Brillouin frequency shifts for various types of optical fibers at room temperature and without longitudinal tensile force are presented. Having database of profiles of the Mandelstam – Brillouin backscattering spectrums for fibers of different kinds and manufacturers allow to classify the optical fibers in the optical cables and detect damaged sections of fiber optical communication line. Keywords: optical fiber, strain, Brillouin frequency shift, Brillouin reflectometry, hyper-acoustic wave