Abstract

In this presentation we generate images of the directional derivative and the Laplacian of the complex index of refraction of a weakly inhomogeneous scattering object. The object is embedded in a known background medium and is probed with coherent plane optical wavefields. The intensity distribution of the wavefields diffracted by the object is then recorded over lines perpendicular to the direction of propagation of the incident waves and is used as input data to a diffraction-tomographic procedure that generates estimates (reconstructions) of the directional derivative and the Laplacian of the index of refraction of the scatterer. The reconstruction algorithm is of the usual filtered-back-propagation type of diffraction tomography,¹ in which appropriate modification of the tomographic filter is required. The success of the procedure, even when only intensity data are available (as is the case in the usual optical scattering experiments),² is discussed briefly and is verified through a number of examples that use both synthetic and experimental data.

© 1990 Optical Society of America