Background: A THz Plasmonic Waveguide Based on Graphene Coated Bow-tie Nanowire
(TPW-GCBN) has been proposed. The waveguide characteristics are investigated by the Finite Element
Method (FEM). The influence of the geometric parameters on propagation constants, electric
field distributions, effective mode areas, and propagation lengths is obtained numerically. The performance
tunability of TPW-GCBN is also studied by adjusting the Fermi energy. The simulation results
show that TPW-GCBN has better mode confinement ability. TPW-GCBN provides a promising alternative
in high-density integration of photonic circuit for the future tunable micro-nano optoelectronic
devices.: Surface plasmonpolaritons based waveguides have been widely used to enhance the local
electric fields. It also has the capability of manipulating electromagnetic fields on the deepsubwavelength.
Objective: The waveguide characteristics of TPW-GCBN should be investigated. The tunability of
TPW-GCBN should be studied by adjusting Fermi energy (FE) which can be changed by the voltage.
Methods: The mode analysis and parameter sweep in Finite Element Method (FEM) were used to
simulate TPW-GCBN for analyzing effective refractive index (neff), electric field distributions, normalized
mode areas (Am), propagation length (Lp) and Figure of Merit (FoM).
Results: At 5 THz, Aeffof λ2/14812,Lp of ~2 μm and FoM of 25 can be achieved. The simulation results
show that TPW-GBN has good mode confinement ability and flexible tunability.
Conclusion: TPW-GBN provides new freedom to manipulate the graphene surface plasmons, and
leads to new applications in high-density integration of photonic circuits for tunable integrated optical