IMAGING OPTICALLY THICK OBJECTS IN SCANNING MICROSCOPY - PERFECTLY CONDUCTING SURFACES

A rigorous numerical simulation of imaging in an optical scanning micr oscope is described. The sample is assumed to be a perfectly conductin g one-dimensional surface-relief object. The approach is capable of ta king into account multiple interactions between the illuminating field and the surface and is also valid for optically thick objects. The re sults are compared with those obtained by use of the Kirchhoff approxi mation and the thin-phase-screen model. We find that for the structure s considered, the Kirchhoff approximation is adequate for describing t he process of image formation, except in those cases in which the surf ace leads to significant amounts of multiple scattering.