Mandel Isroel M, Bendoym Igor, Jung Young U, Golovin Andrii B, Crouse David T
Opt Express. 2013 Dec 30;21(26):31883-93. doi: 10.1364/OE.21.031883.
In this work, it is shown how the shapes of surface plasmon dispersion curves can be engineered by manipulating the distribution of the electromagnetic fields in multilayer structures, which themselves are controlled by the free electron density in metal-like materials, such as doped semiconductors in the THz spectral range. By having a nonuniform free electron density profile, reduced relative to that in typical bulk metals, the electromagnetic fields of surface plasmons are distributed in different metallic materials that have different complex dielectric permittivities. As the in-plane component of surface plasmon's wave-vector increases, they become more confined to a particular layer of the multilayer structure and have energies that are predictable by considering the permittivity of the layer in which the fields are most concentrated. Unusual and arbitrary shapes of surface plasmon dispersion curves can be designed, including stair steps and dovetails shapes.
在这项工作中，展示了如何通过操纵多层结构中电磁场的分布来设计表面等离激元色散曲线的形状，而多层结构本身又由类金属材料（如太赫兹光谱范围内的掺杂半导体）中的自由电子密度控制。通过具有相对于典型块状金属降低的非均匀自由电子密度分布，表面等离激元的电磁场分布在具有不同复介电常数的不同金属材料中。随着表面等离激元波矢的面内分量增加，它们会更局限于多层结构的特定层，并且通过考虑场最集中的层的介电常数可以预测其能量。可以设计出表面等离激元色散曲线的异常和任意形状，包括阶梯状和燕尾状。
