Fig. 3.

(a) Plot showing acoustic waveforms propagating through optical fibers of different lengths ranging from 10 to 35 cm. (b) Plot of the time delay versus the corresponding fiber length. The average acoustic velocity in the silica fiber is $\sim 5108\mathrm{m}/\mathrm{s}$. (c) Attenuation of acoustic signals through optical fibers of various lengths. The average attenuation is $\sim 0.2\mathrm{dB}/\mathrm{cm}$ ($0.1\mathrm{dB}/\mu \mathrm{s}$).