Modal-based tomographic imaging from far-zone observations: multifrequency case.

A recently developed optical diffraction tomography technique [J. Opt. Soc.

Modal-based tomographic imaging from far-zone observations.

A novel method of optical diffraction tomography (ODT) to image weakly scattering, electrically large, two-dimensional (2D) objects using the far-zone scattered field data is presented. The proposed technique is based on the expansion of the target object function in terms of Fourier-Bessel basis functions and an alternative approximation for the total electric field within the support of the investigated scatterer. Analytical (Mie) plane-wave scattering by a layered, circularly symmetric, lossy cylinder, and finite-difference time-domain simulations involving plane-wave scattering by a more general, lossless phantom are utilized to compare the performance of the proposed method with that of the standard ODT techniques, which are based on the Born approximation and the Fourier diffraction theorem.

Model for continuously scanning ultrasound vibrometer sensing displacements of randomly rough vibrating surfaces.

An analytic model is developed for the time-dependent ultrasound field reflected off a randomly rough vibrating surface for a continuously scanning ultrasound vibrometer system in bistatic configuration. Kirchhoff's approximation to Green's theorem is applied to model the three-dimensional scattering interaction of the ultrasound wave field with the vibrating rough surface. The model incorporates the beam patterns of both the transmitting and receiving ultrasound transducers and the statistical properties of the rough surface.