Surface local field effect in the optical properties of GaAs(110) and GaP(110),

A method for the calculation of the surface local-field effect on reflectance has been developed. It also takes into account the different polarizabilities of surface and bulk. Application has been made to GaAs(110) and GaP(110), starting from first-principles one-electron calculations of surface optical properties. The inclusion of local fields has important—yet not drastic—effects on line shapes of reflectance-anisotropy and differential-reflectivity measurements.