Linear optical properties of gold nanoshells

A metal nanoshell consists of a nanometer-scale dielectric core surrounded by a thin metallic shell. The plasmon resonance of metal nanoshells display s a geometric tunability controlled by the ratio of the core radius to the total radius. For gold-coated Au2S this ratio varies from 0.6 to 0.9, yield ing a plasmon resonance tunable from 600 to greater than 1000 nm. Mie scatt ering theory for the nanoshell geometry quantitatively accounts for the obs erved plasmon resonance shifts and linewidths. In addition, the plasmon lin ewidth is shown to be dominated by electron surface scattering. (C) 1999 Op tical Society of America [S0740-3224(99)02910-0].