Full field tomographic reconstruction of sound fields using TV holography

Abstract

A vibrating sound source causes periodic variations of the refractive index in the surrounding medium. A light wave passing through the sound field will experience a corresponding variation of its path length which can be measured by interferometric techniques like TV holography. One TV-holography recording represents the integrated optical pathlength in one direction. The sound source is rotated to record cross sections of the field as seen from different directions. By tomographic backprojection of these recordings, afterward the amplitude and phase of the sound field in any plane of the volume are reconstructed.