title: Optical antenna effect in semiconducting nanowires.
abstract: We report on investigations of the interaction of light with nanoscale antennae made from crystalline GaP nanowires (NWs). Using Raman scattering, we have observed strong optical antenna effects which we identify with internal standing wave photon modes of the wire. The antenna effects were probed in individual NWs whose diameters are in the range 40 < d < 300 nm. The data and our calculations show that the nature of the backscattered light is critically dependent on the interplay between a photon confinement effect and bulk Raman scattering. At small diameter, d < 65 nm, the NWs are found to act like a nearly perfect dipole antenna and the bulk Raman selection rules are masked leading to a polarized scattering intensity function I R approximately cos4 theta. Underscoring the importance of this work is the realization that a fundamental understanding of the "optical antenna effect" in semiconducting NWs is essential to the analysis of all electro-optic effects in small diameter filaments.
authors.affiliation: Department of Physics, Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: G
authors.initials: G
authors.lastname: Chen
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Qiujie
authors.initials: Q
authors.lastname: Lu
authors.forename: H R
authors.initials: HR
authors.lastname: Gutierrez
authors.forename: Qihua
authors.initials: Q
authors.lastname: Xiong
authors.forename: M E
authors.initials: ME
authors.lastname: Pellen
authors.forename: J S
authors.initials: JS
authors.lastname: Petko
authors.forename: D H
authors.initials: DH
authors.lastname: Werner
authors.forename: P C
authors.initials: PC
authors.lastname: Eklund
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D005708:Gallium / Q000737:chemistry*; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D010720:Phosphines / Q000737:chemistry*; D012542:Scattering, Radiation; D012666:Semiconductors
chemical_list: D046911:Macromolecular Substances; D010720:Phosphines; C485338:gallium phosphide; D005708:Gallium