Tensile-strain coefficient of resonance frequency of depolarized guided acoustic-wave Brillouin scattering

With the aim of making a tensile-strain sensor or a temperature sensor based on depolarized guided acoustic-wave Brillouin scattering (GAWBS), we experimentally investigate the effect of tensile strain applied to a fiber. We pay our attention to the resonance frequency of depolarized GAWBS by the TR25 mode of the acoustic wave. By unjacketing the fiber, the peak level of the resonance spectrum increases and the full-width at half-maximum narrows to 500 kHz, which increases the accuracy of measurement. The experimentally obtained tensile-strain coefficient is 1,8, On the basis of our experimental results, we discuss the way to apply depolarized GAWBS to a tensile-strain sensor or a temperature sensor.