Light absorption by surface nanoholes and nanobumps.

Highlights • Non-radiative patterns near surface holes and bumps are inversed. • Far-field maxima and minima positions are inversed for holes and bumps. • Interference maxima have opposite orientation on glass and metal surfaces. • Interference maxima qualitatively differ for holes and voids close to surface. • Less pronounced patterns for short pulses with finite spectral bandwidth. • Asymmetric shape may switch the absorbed energy maxima positions. • Multiple holes and bumps generate joint interference patterns on the surface. Abstract This paper deals with a numerical investigation of the energy deposition induced by ultrafast laser interaction with nanostructures. We calculate and analyze the intensity near-field reactive and radiative patterns resulted from the interference of the incident light with light scattered by individual subwavelength holes and bumps on the surface of metallic and dielectric materials. The role of light polarization, optical material properties, collective effects and nature of the imperfections in localized energy absorption is elucidated. The results open new perspectives in precise light manipulation by surface inhomogeneities and well-controlled surface nanostructuring by ultrashort laser. [ABSTRACT FROM AUTHOR]