TOMOGRAPHIC RECONSTRUCTION FROM OPTICAL SCATTERED INTENSITIES

A generalized tomographic reconstruction procedure is described for determining the complex-valued index-of-refraction distribution of a semitransparent, three-dimensional inhomogeneous object from observations of the far-field intensity patterns generated by the object in a sequence of scattering experiments. The inversion procedure is based on the wave equation governing the scattered optical field and fully accounts for the diffraction and propagation effects associated with the interaction of the incident wave with the object and the subsequent free-space propagation of the scattered wave to the wave zone (far field). The reconstruction of the object's index-of-refraction distribution is performed digitally directly from the far-field intensity of the scattered wave and does not require direct measurement or retrieval of the phase of the scattered field. An optical scattering experiment is reported in which the cross-sectional profile of the index-of-refraction distribution of an optical fiber is reconstructed from the measured intensity of the diffraction pattern of the fiber by using the described inversion procedure.