Optical properties of gold nanorings.

The optical response of ring-shaped gold nanoparticles prepared by colloidal lithography is investigated. Compared to solid gold particles of similar size, nanorings exhibit a redshifted localized surface plasmon that can be tuned over an extended wavelength range by varying the ratio of the ring thickness to its radius. The measured wavelength variation is well reproduced by numerical calculations and interpreted as originating from coupling of dipolar modes at the inner and outer surfaces of the nanorings. The electric field associated with these plasmons exhibits uniform enhancement and polarization in the ring cavity, suggesting applications in near-infrared surface-enhanced spectroscopy and sensing.

[1]  F. G. D. Abajo,et al.  Retarded field calculation of electron energy loss in inhomogeneous dielectrics , 2002 .

[2]  A. Wei,et al.  Tunable surface-enhanced Raman scattering from large gold nanoparticle arrays. , 2001, Chemphyschem : a European journal of chemical physics and physical chemistry.

[3]  Daniel Courjon,et al.  Near field optics , 1993 .

[4]  J. Aizpurua,et al.  Electromagnetic coupling on an atomic scale. , 2002 .

[5]  Hongxing Xu,et al.  Spectroscopy of Single Hemoglobin Molecules by Surface Enhanced Raman Scattering , 1999 .

[6]  W. Steen.  Absorption and Scattering of Light by Small Particles , 1999 .

[7]  Michael Vollmer,et al.  Optical properties of metal clusters , 1995 .

[8]  Andrew G. Glen,et al.  APPL , 2001 .

[9]  Steven R. Emory,et al.  Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering , 1997, Science.

[10]  Kazuaki Sakoda,et al.  Optical Properties of Photonic Crystals , 2001 .

[11]  E. Palik.  Handbook of Optical Constants of Solids , 1997 .

[12]  R. Dasari,et al.  Single Molecule Detection Using Surface-Enhanced Raman Scattering (SERS) , 1997 .

[13]  S. L. Westcott,et al.  Infrared extinction properties of gold nanoshells , 1999 .

[14]  George C. Schatz,et al.  Nanosphere Lithography: Surface Plasmon Resonance Spectrum of a Periodic Array of Silver Nanoparticles by Ultraviolet−Visible Extinction Spectroscopy and Electrodynamic Modeling , 1999 .

[15]  F. G. D. Abajo,et al.  RELATIVISTIC ELECTRON ENERGY LOSS AND ELECTRON-INDUCED PHOTON EMISSION IN INHOMOGENEOUS DIELECTRICS , 1998 .

[16]  Naomi J. Halas,et al.  Silver Nanoshells: Variations in Morphologies and Optical Properties , 2001 .

[17]  Lechner,et al.  Metal nanoparticle gratings: influence of dipolar particle interaction on the plasmon resonance , 2000, Physical review letters.