Sung Ming-Je, Ma Yao-Feng, Chau Yuan-Fong, Huang Ding-Wei
Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan.
Appl Opt. 2010 Feb 10;49(5):920-6. doi: 10.1364/AO.49.000920.
A hexagonal nanostructure formed by seven core shell nanocylinders filled with different dielectric cores is investigated. The surface plasmon resonance in such a hexagonal nanostructure under conditions of different illumination wavelengths, dielectric cores, angles of incidence, and thicknesses of silver shells is studied by use of the finite element method. Simulation results show that the resonant wavelength is redshifted as the dielectric constant and the size of the core increase. The peak resonant wavelength and the local field enhancement are approximately proportional to the radius of the dielectric core. Additionally, the surface plasmon field excited by TM-polarized light at the incident angle of theta=15 degrees is exactly a linear combination of those excited at incident angles of theta=0 degrees and 30 degrees, confirming the linear nature of the surface plasmon resonance in a nanostructure formed by linear media.
研究了一种由七个填充不同介电芯的核壳纳米圆柱体形成的六边形纳米结构。利用有限元方法研究了这种六边形纳米结构在不同照明波长、介电芯、入射角和银壳厚度条件下的表面等离子体共振。模拟结果表明，随着介电常数和芯尺寸的增加，共振波长发生红移。峰值共振波长和局部场增强与介电芯的半径近似成正比。此外，在入射角θ = 15度时由TM偏振光激发的表面等离子体场恰好是在入射角θ = 0度和30度时激发的表面等离子体场的线性组合，证实了由线性介质形成的纳米结构中表面等离子体共振的线性性质。
