Characterization of longitudinal acoustic waves in a fiber using an extrinsic Fabry-Perot interferometer

Longitudinal acoustical modes propagating in a fiber are characterized using an extrinsic Fabry-Perot interferometer. The method allows the detection of the fiber axial deflection peaks which correspond to the acoustic resonances. The method can be further used for estimating properties of acoustic excited fibers, such as acoustic frequency and wavelength, which are essential in the design of acousto-optic devices employing Bragg gratings