Contribution of the Internal Field to the Anisotropic Optical Reflectance of GaP(110)

This article presents the theory of optical reflection from thin slabs of Gap( 1 10) by means of the discrete dipole model and focusses especially upon the possible implications of this model for the surface induced optical anisotropy. The reflectance of a semi-infinite sample is extracted from slab calculations and compared with experiments. We find that the internal field has a very important role in determining the surface induced optical anisotropy. We also show that the surface sensitivity of such experiments can be estimated to be about five monolayers.