Second-harmonic generation from simple metal surfaces and from adsorbed alkali monolayers

Abstract

The nonlinear surface polarization which is primarily responsible for the surface sensitivity of optical second-harmonic generation, has recently been calculated for various simple metal surfaces and for thin adsorbed alkali overlayers. These calculations are based on the time-dependent density functional approach, i.e. the details of the ground state electron distribution at the surface as well as the self-consistent response to the applied electromagnetic field are fully taken into consideration. The nonlinear dipole moment of the induced surface charge exhibits characteristic spectral features which are closely related to corresponding features shown by the linear dipole moment.