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 TR/sub 25/ 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.