沿石墨烯薄层传播的非线性表面等离激元

Nonlinear surface plasmons propagating along graphene sheets

分析了沿石墨烯覆盖的各向异性Kerr非线性介质表面传播的非线性表面等离激元的性质。根据麦克斯韦方程组和边界条件并把石墨烯模拟为无限薄的表面电导率,导出了表面等离激元的色散关系。数值结果表明,当表面等离激元的传播常数小于某个临界值时,其色散曲线出现"双稳"态。改变石墨烯的化学势、光强或非线性系数可以有效地控制表面等离激元的色散和传播性质。

In this paper, we analyzed the nonlinear surface plasmons （SPs） propagating along the graphene sheets sandwiched between an anisotropic Kerr-type nonlinear medium and a linear isotropic medium. Following MaxwelFs equations and the boundary conditions and modeling graphene as an infinitesimally thin surface con- ductivity, we derived the dispersion of the nonlinear SPs. The numerical results indicate that the dispersion of the SPs exhibits bistability when the propagation constants are smaller than their critical values. The dispersion and propagation properties of the SPs can be effectively controlled by changing the chemical potential of the graphene, the optical intensity or the nonlinear coefficient.