Images of strips on and trenches in substrates

The computation of images of lines or strips on a substrate and trenches in a substrate or a layer above a substrate, all made of dielectric or conducting materials, is presented. The method is based on integral equations, of the single-integral-equation kind, equivalent to Maxwell's equations and on Fourier optics. Examples of computed images illustrating some of the features found in the images are provided. Approximations involved in the model of the actual scatterer and microscope as well as in the theoretical and numerical representations are discussed.