OPTICAL REFLECTANCE ANISOTROPY OF AG AND AU (110) SINGLE-CRYSTALS

We have developed a theoretical model for describing the electromagnet ic response of noble metal surfaces. The model takes into account the d to s-p interband transitions as well the actual crystalline geometry . The surface response is incorporated in a calculation of the optical reflectance, and it yields corrections to Fresnel's formulae which de pend on the angle between the polarization vector and the surface prin cipal directions. The anisotropy effect has been confirmed by surface reflectance anisotropy spectroscopy experiments performed on (110) Ag and Au surfaces. We show that the main contribution to the anisotropy is the screened surface local-field effect on resonant dipolar oscilla tions localized near the surface.