基于有限元方法,通过改变有限长金属纳米线的长度、半径、介质有效折射率以及有限长金属纳米线和波导之间的距离,研究了有限长金属纳米线对纳米线波导传输特性的调控效果。结果表明:沿有限长金属纳米线长度方向,表面等离极化激元在两金属纳米线耦合区域内形成共振。随着有限长金属纳米线长度的增加,透射率逐渐减小,并呈周期性变化。随着金属纳米线半径和介质衬底有效折射率的增大,复合波导的透射率均相应增大。透射率与两根纳米线间距紧密相关,当金属纳米线取不同半径值,两根纳米线间距为20nm左右时透射率均达到最小值;当两根金属纳米线间距较大时,透射率不再明显变化。
Using the finite element method,the propagation properties of the nanowire waveguide in parallel to a finite length metal nanowire are investigated with varying the length and radius of metal nanowire,the effective refractive index of medium,and the distance between the nanowire and waveguide.The results show that the surface plasmon polaritons resonance is formed in the coupling area along the length of the metal nanowire direction.With the increase in length of finite metal nanowire length,the transmittance decreases periodically.The transmittance of hybrid waveguide is affected by the radius of finite length metal nanowires.The transmittance increases with increasing radius of the nanowire as well as the refractive index of dielectric substrate.In addition,the transmittance is closely related with the distance between the finite length metal nanowire and waveguide,and there has minimum transmittance when the distance is 20 nm.