A planar ultrasonic tomography using shear waves

The authors study the effect of using shear waves in scanning acoustic microscopy in which the specimens are solid. For any specimen with a shear modulus immersed in the microscope's water bath, mode conversion will take place at the water-solid interface. In order to compare the operation of shear-wave tomography with that of longitudinal-wave tomography the authors have simulated tomographic reconstruction for each. Shear-wave velocities are lower than those of longitudinal-wave and hence the wavelengths at the same frequency are smaller. For this and other reasons the authors can expect that the resolution of shear-wave tomography to be substantially better than that for longitudinal-wave tomography.