提出了一种工作于太赫兹波段的、基于半圆柱形“不平坦”InSb基底结构的混合等离子体波导.分析了半导体材料InSb的相对介电常量随工作频率的变化特性, 重点研究了该混合波导以及两种不同形变结构的有效模场面积、传播长度、品质因数、能量分布等随波导工作频率、波导尺寸的变化情况.结果表明, 本文提出的“不平坦”基底结构波导可以达到与传统结构几乎相同的传播长度, 有效模场面积较传统结构减小了一个数量级以上, 具有非常强的模场约束性, 适合于太赫兹频段高密度集成电路中的应用.

A kind of hybrid surface plasmonic waveguide working in the terahertz frequency range and based on un-flat substrate structure was proposed. The relative permittivity of InSb changed with the working frequency was investigated. The mode properties of the proposed structure and two other un-flat substrate structures, such as the effective mode area, propagation length, figure of merit and energy ratio, were investigated in detail by varying with the working frequency and geometrical parameters. The results show that the proposed structure can reach the same propagation length with the traditional structure, while the mode area of the proposed structure is smaller by more than an order of magnitude compared with that of the traditional hybrid waveguide, which indicates stronger mode confinement. The proposed waveguide satisfies the requirement of the application in high density circuits in the terahertz range.