Compared with continuous ultrasound wave, pulsed ultrasound has been widely used in ultrasound imaging. The aim of this work is to show the applicability of acousto-optic diffraction on pulsed ultrasound transducer. In this paper, acoustic pressure of two ultrasound transducers is measured based on Raman-Nath diffraction. The frequencies of transducers are 5MHz and 10MHz. The pulse–echo method and simulation data are used to evaluate the results. The results show that the proposed method is capable to measure the absolute sound pressure. We get a sectional view of acoustic pressure using a displacement platform as an auxiliary. Compared with the traditional sound pressure measurement methods, the proposed method is non-invasive with high sensitivity and spatial resolution.
Wavelet transform (WT) was exploited to measure distances based on spectrum interferometry. Complex Morlet wavelet was used as the mother wavelet to obtain the amplitude graph and phase graph simultaneously, and the latter showed the wrapped phase in fact. The distances were measured numerically and experimentally, and each distance for ten times. Experimental results indicated that the distance could be obtained uniquely using wavelet transform, and the reproducibility deviation was 77.7 nm when the measured distance is about 1 mm.