| Popis: |
A kind of metal-dielectric-metal(MDM) plasmonic waveguide with double parallel cylindrical nanorods was investigated.The propagation properties of the waveguide structure were analyzed using the finite-difference time-domain(FDTD) method.The results show that the electromagnetic field is well confined to the dielectric layer and the intermediate region formed by the two cylindrical nanorods when the incident light is perpendicular to the major axis,so the filed can be efficiently coupled into the waveguide.At the working wavelength λ = 1 550 nm,the effective index decreases with the increase of the inner radius r1,meanwhile the propagation length increases as the inner radius r1 increases.However,in the case of larger d,the effective index becomes large,and the propagation length becomes short.In addition,the field can be predominantly confined within the dielectric layer in the case of g = 20 nm.In short,adjusting the geometrical parameters can significantly improve the confinement of the SPPs fields and reduce the losses of the waveguide,so that the effective refractive index and propagation length of the waveguide can be optimized.Subwavelength optical confinement can be achieved in this kind of plasmonic waveguide,which will be applied to the fields of photonic device integration and sensors. |
