色散金属的时域有限差分方法

表面等离子体激元具有使光场局域化和局域电磁场增强等特性,在纳米光子学和微观检测等诸多领域显示出广泛的应用潜力.时域有限差分（FDTD）数值计算方法能仿真激光与亚波长金属微结构相互作用的表面等离子体效应.金属具有色散性质,其相对介电常数模型有Drude模型和Lorentzs模型及它们相结合的Drude-Lorentzs模型,能拟合金属在可见光和近红外部分或全部波段的色散特性.FDTD数值计算要采用增加辅助变量和相应的辅助差分方程的方法使FDTD迭代计算稳定.

Finite-Difference Time-Domain Method of Dispersion Metal

Surface plasmon polaritons（SPPs） have some characteristics such as optical field localization and local electromagnetic field enhancement and so on,so it exhibits extensive potential application in nano-photonics and microscopic detection and many other domains.The finite-difference time-domain（FDTD） numerical method can simulate the surface plasmon（SP） effect of laser interaction with the subwavelength metal microstructure.The relative dielectric constant of metal is frequency dependent（dispersion）.There are three dispersion models about metal＇s relative dielectric constant in visible light and near-infrared wave band,such as Drude model,Lorentzs model and Drude-Lorentzs mode.In order to get FDTD iterative computation stable,FDTD numerical method should increase the subsidiary variable and the corresponding auxiliary difference equation.