Mode analysis of surface plasmon metal-dielectric-metal nanowire array waveguide at sub-wavelength scale

摘要

A kind of surface plasmon waveguide (SPW) formed from metal-dielectric- metal nanowire array is proposed. The mode properties are analyzed. Theoretical analysis reveals that at appropriate geometrical parameters, the optimal mode properties such as longer propagation length and better sub-wavelength mode confinement can be obtained. It is found that when the center dielectric nanowire is replaced by gain medium, the propagation length can be extended obviously without changing the effective mode index and mode size clearly. The studied waveguide could be an interesting alternative to the application of realizing high density photonic devices integration, nanoscale photonic circuits and sensors.