MXene-based hybrid plasmonic waveguides with strong field confinement and low crosstalk

Abstract

MXene exhibits unique plasmonic properties in the near-infrared region, which have garnered significant research interest. However, MXene plasmons typically suffer from weak field confinement and high losses. The present work proposes a hybrid plasmonic waveguide consisting of a silica layer inserted between the MXene film and a Si strip waveguide. By analyzing the thickness-dependent dielectric properties of MXene, a thickness of 10 nm is identified as optimal choice owing to its superior material quality factor. With finite element analysis, the modal characteristics are systematically investigated at the wavelength of 1550 nm. The results demonstrate that the plasmon mode in proposed waveguide exhibits strong modal field confinement, with a minimum modal area of 1.335 × 10⁻⁴A₀ (where A₀ = λ²/4), and achieves a stable figure of merit. Compared with a 75-nm-thick MXene layer, the 10-nm-thick layer enables smaller integration spacing and lower crosstalk in coupled systems. These findings may contribute to the design of high-performance MXene photonic devices with reduced crosstalk.