A reliability study of light refractive tomography utilized for noninvasive measurement of ultrasound pressure fields

Light refractive tomography is an optical measurement technique that is able to provide absolute sound pressure values in specified volumes. Because of the simplicity of the measurement principle as well as the compactness of the measurement setup, light refractive tomography offers higher measurement performance and fewer error sources than light diffraction tomography. In this contribution, a numerically simulated ultrasound pressure field is exploited to determine the experimental parameters and to analyze the error sources as well as their influences on final results. After that, several ultrasound transducers excited with 1 MHz signals are investigated. The light refractive tomography results show good agreement with hydrophone measurements. Finally, we reconstruct 2000 transient states of the ultrasound pressure field within a volume of about 38 cm³ after sending the burst signal. Without applying any smoothing to the resulting images, the reconstructed pressure field varies continuously in both spatial and temporal dimensions.