Microscopic treatment of the angular dependence of surface induced optical anisotropy

The angular dependency of surface induced optical anisotropy (SIOA) has been calculated by means of the discrete dipole approach. Within the basic assumptions of this approach, exact results (full incorporation of local-field effects and retardation) have been obtained for the semi-infinite problem using the double-cell method. This method allows for an independent treatment of bulk and surface. For off-normal incidence, the microscopic behavior of the system has been investigated. Near the Brewster angle, the absolute value of the microscopic p-type response is larger than the s-type response. In general, the SIOA decreases for increasing angles of incidence. Only near Brewster’s angle the relative p-type anisotropic reflectance difference increases dramatically, but under experimentally very unstable conditions. Further, the macroscopic anisotropic response, ${\mathit{dR}}_{\mathit{s}}$/${\mathit{R}}_0$, ${\mathit{dR}}_{\mathit{p}}$/${\mathit{R}}_0$, δΨ, and δΔ, has been calculated as a function of photon energy for three angles of incidence, 60°, 70°, and 80°, and for the (110) surfaces of three popular semiconductors, Si, GaP, and GaAs, respectively.