SSHG of uniaxial molecules: Phenomena near brewster's angle

The nonlinear optical behaviour of a crystalline adlayer of unidirectionally oriented macromolecules at a substrate is studied by means of the discrete dipole model. Polar and azimuthal dependence of the second harmonic pp-reflectance is investigated at the fundamental and second harmonic frequencies. The influence of the anisotropic linear properties of the adlayer turns out to be essential

Optical anisotropy of Ge(001)

The surface induced optical anisotropy in the electronic structure of clean Ge(001) 2×1 was studied with an ellipsometer at normal incidence. The change in the reflection difference between light polarized parallel and perpendicular to the dimer bond at this surface upon either absorption of molecular oxygen or Ar+ ion bombardment was recorded. Both procedures were found to give the same results. It was possible to obtain a qualitative agreement of the optical spectrum recorded and the position and parity of the occupied and unoccupied surface states known on the clean surface

Effect of linear polarisability and local fields on surface SHG

A discrete dipole model has been developed to describe Surface Second Harmonic Generation by centrosymmetric semiconductors. The double cell method, which enables the linear reflection problem to be solved numerically for semi-infinite systems, has been extended for the nonlinear case. It is shown that a single layer of nonlinear electric dipoles at the surface and nonlocal effects allows to describe the angle of incidence dependent anisotropic SHG obtained from oxidised Si(001) wafers. The influence of the linear response, turns out to be essential to understand the anisotropic SHG-process

Full microscopic treatment of the optical response of the Si(100)2x1 surface

The optical reflection from the Si(100) 2 × 1 surface has been calculated, using the discrete dipole model and local polarizabilities obtained from quantum mechanical cluster calculations. Results have been compared with experimental differential reflectance (Si) and optical anisotropy measurements (Ge)