Abstract

The electromagnetic field scattered from an inhomogeneous dielectric slab is calculated by both approximate and exact methods. A novel inverse solution is found using WKB wave functions as approximations of the exact solution. The solution employs the correct EM boundary conditions and is, therefore, able to account for both surface and volume scattering effects. This enables the size and strength of the inhomogeneity to be determined. Examples of scattering from objects of variable size and strength are presented with corresponding quantitative inverse solutions. When applied to exact forward data, the inversion algorithm quantitatively reconstructs the permittivity and size of the object to an accuracy within 5 and 20 %, respectively. A comparison is made with a reconstruction based on the first Born approximation, which is found to be neither qualitatively nor quantitatively accurate.

© 1987 Optical Society of America