Coupling characteristics of dielectric-loaded surface plasmon polariton waveguides: a simple method of analysis

摘要

A simple method to obtain the coupling characteristics of a directional coupler consisting of two dielectric-loaded surface plasmon polariton waveguides is reported. The method is found to give accurate results in comparison with the widely used effective index method. Theoretical results are also found to match excellently with recently reported measurements on coupling lengths in such waveguides [Opt. Lett. 34, 310 (2009)].