In this work, we demonstrate surface plasmon resonance properties and field confinement under a strong interaction between a waveguide and graphene nanoribbons (GNRs), obtained by coupling with a nanocavity. The optical transmission of a waveguide-cavity-graphene structure is investigated by finite-difference time-domain simulations and coupled-mode theory. The resonant frequency and intensity of the GNR resonant modes can be precisely controlled by tuning the Fermi energy and carrier mobility of the graphene, respectively. Moreover, the refractive index of the cavity core, the susceptibility χ⁽³⁾ and the intensity of incident light have little effect on the GNR resonant modes, but have good tunability to the cavity resonant mode. The cavity length also has good tunability to the resonant mode of cavity. A strong interaction between the GNR resonant modes and the cavity resonant mode appears at a cavity length of L₁ = 350 nm. We also demonstrate the slow-light effect of this waveguide-cavity-graphene structure and an optical bistability effect in the plasmonic cavity mode by changing the intensity of the incident light. This waveguide-cavity-graphene structure can potentially be utilised to enhance optical confinement in graphene nano-integrated circuits for optical processing applications.

在这项工作中，我们展示了在波导与石墨烯纳米带（GNR）之间的强相互作用下，通过与纳米腔耦合获得的表面等离子体共振特性和场约束。通过有限差分时域仿真和耦合模式理论研究了波导腔石墨烯结构的光传输。可以分别通过调节石墨烯的费米能量和载流子迁移率来精确控制GNR共振模式的共振频率和强度。而且，型腔芯的折射率，磁化率χ ^（3）入射光的强度对GNR谐振模式影响不大，但对谐振腔谐振模式具有良好的可调性。腔的长度对于腔的共振模式也具有良好的可调谐性。在腔长度为L ₁ = 350 nm时，GNR共振模式和腔共振模式之间会出现强烈的相互作用。通过改变入射光的强度，我们还证明了这种波导-腔-石墨烯结构的慢光效应和等离激元腔模中的双稳态光学效应。该波导腔-石墨烯结构可潜在地用于增强用于光学处理应用的石墨烯纳米集成电路中的光学限制。