High accuracy measurement of Poisson's ratio of optical fibers and its temperature dependence using forward-stimulated Brillouin scattering

Transverse acoustic mode resonances enable a high accuracy determination of Poisson's ratio and elastic properties of optical fibers. An all-optical pump and probe technique is used for efficient excitation and accurate characterization of both, radial and torsional-radial acoustic resonances of optical fibers. Simple and precise algebraic expressions for the frequencies of high order acoustic resonances are derived, enabling a rigorous analysis of the experimental data using standard least squares fitting. Following this approach, the determination of Poisson's ratio does not require the measurement of any physical length, but only frequency measurements are required. An accuracy better than 1 parts per thousand is achieved. The dependence of the fiber Poisson's ratio with temperature is also determined experimentally. (c) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

Transverse acoustic mode resonances allow for the accurate determination of Poisson's ratio and elastic properties of optical fibers. An all-optical pump and probe technique is used to efficiently excite and accurately characterize radial and torsional-radial acoustic resonances of optical fibers. Simple algebraic expressions for the frequencies of high order acoustic resonances are derived, enabling rigorous analysis of experimental data using standard least squares fitting. This approach eliminates the need to measure physical lengths for determining Poisson's ratio, as frequency measurements alone are sufficient. An accuracy better than 1 parts per thousand is achieved. The experimental dependence of fiber Poisson's ratio on temperature is also determined.