Seal K, Genov D A, Sarychev A K, Noh H, Shalaev V M, Ying Z C, Zhang X, Cao H
Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
Phys Rev Lett. 2006 Nov 17;97(20):206103. doi: 10.1103/PhysRevLett.97.206103.
Near-field intensity statistics in semicontinuous silver films over a wide range of surface coverage are investigated using near-field scanning optical microscopy. The variance of intensity fluctuations and the high-order moments of intensity enhancement exhibit local minima at the percolation threshold. This reduction in local field fluctuations results from resonant excitation of delocalized surface plasmon modes. By probing the modification of the critical indices for high-order moments of intensity enhancement caused by the delocalized states, we provide the first experimental evidence for the coexistence of localized and delocalized surface plasmon modes in percolating metal films.
利用近场扫描光学显微镜研究了在大范围表面覆盖率下的半连续银膜中的近场强度统计。强度涨落的方差和强度增强的高阶矩在渗流阈值处呈现局部最小值。局部场涨落的这种降低是由离域表面等离子体激元模式的共振激发引起的。通过探测由离域态引起的强度增强高阶矩的临界指数的变化，我们为渗流金属膜中局域和离域表面等离子体激元模式的共存提供了首个实验证据。
