Discrete plasmonic Talbot effect in finite metal waveguide arrays.

ABSTRACT

We introduce supermode theory into the propagation of surface plasmon polaritons (SPPs) in nanoscale metal waveguide arrays (MWGAs). The SPP supermodes in finite MWGAs are analyzed and the coefficient of excited supermodes can be determined quantitatively. The field intensity distributions in finite MWGAs can be explained by the superposition of the excited SPP supermodes. The discrete plasmonic Talbot effect in a finite MWGA is achieved successfully by adjusting different intensity for each input field. We also find that the period condition of the input fields in MWGAs is not the same with conventional dielectric waveguides. The theory is verified by the finite difference time-domain (FDTD) method.