▎ 摘　　要

In this paper, a single-mode graphene loaded double ridge plasmon waveguide (GDRW) with long propagation length and strong mode confinement is proposed. The characteristics of the guided modes are investigated in detail, and tunable single-mode transmission with good performance can be realized either by changing the Fermi energy level or by optimizing the key structural parameters. High figures of merit and much lower crosstalk are obtained due to the dramatically suppressed interference between two parallel placed GDRWs, enabling thereby more tightly stacking in terahertz integrated circuits. Further investigation on fabrication errors, such as the horizontal misalignment of the two symmetric ridges, fabrication distortion of rectangular ridges, and variation of ridge tip curvature radius, indicates that the proposed structure has enough fabrication error tolerance. The results are greatly expected to facilitate the application of high-density terahertz integrated circuits.