Color view of atomic highs and lows in tunneling induced light emission

Based on a detailed experimental study of light emission stimulated with a scanning tunneling microscope, we put forward a consistent picture for the atomic-scale contrasts observed to date on noble metal surfaces. Divergent contrasts near various atomic steps and conflicting interpretations of light emission from a model atomic grating, (2x1) reconstructed Au(110), are accounted for. The light intensity modulation results from different spatial distributions of the local density of final states in the elastic and inelastic tunneling channels.