Information extraction from acoustic signals by optical fibre interferometry techniques based on chromatic modulation

A technique for interpreting acoustic signals is presented based on an extension of the chromatic analysis used successfully in the optical domain. To illustrate the potential of this interpretation technique it was applied to monitoring power switchgear because of the inherent complexity of the various phenomena involved and their interaction with each other. In particular, we present a technique for analysing acoustic vibration data that provides extended information about the frequency content of a signal, requires little processing and data storage overhead and which can easily be adapted to a wide range of applications. The proposed technique is based on chromatic sensing which has been widely applied in the optics field and its advantages over Fourier Transformation are well demonstrated through experimental tests.