Abstract

A novel fibre-optic transducer is presented that is capable to convert a vibration signal into a spatially changing strain profile. Static loading experiments were performed using swept-wavelength interferometry (SWI) to characterise the distributed strain profile of the sensor. Based on this, the strain response of each fibre section was calculated for coherent optical time domain reflectometry (C-OTDR) as a function of pulse width and spatial sampling interval. The resulting strain response of the sensor spans over two orders of magnitude. With the help of this transducer and using only the intensity information of the C-OTDR, we were able to determine vibration spectra without additional harmonic frequencies for accelerations between 0.01 ms^-2 and 0.2ms^-2.

© 2023 The Author(s)