Quantitative reconstruction of ultrasound fields in optically transparent isotropic solids

This contribution reports on a method of utilizing light refractive tomography (LRT) to reconstruct ultrasound dilatation fields in optically transparent isotropic solids. Furthermore, it proposes the description of ultrasound in solids using a normal stress component, which shares the same unit with sound pressure and can be approximately derived from dilatation. After giving the theoretical support for this novel application, we reconstruct the distribution of normal stress σ zz in a cross section within poly(methyl methacrylate) (PMMA). Because of the lack of techniques for verifying the measurement results directly, systematic errors of the LRT measurements in PMMA are checked by comparing the results from LRT and hydrophone measurements in water. The small differences relative to the maximum pressure (e.g.,