Single- and Multimode Beam Propagation Through an Optothermally Controllable Fano Clusters-Mediated Waveguide

Plasmonic waveguides are strategic compact structures consisting of nanoscale components and/or particles to carry the light. Here, by proposing a systematic and artificial configuration of fused nanoparticle assemblies, we develop an optothermally controllable plasmonic waveguide with high and tunable decay length for propagation of both single- and multimode waves. Using symmetric nanoplasmonic clusters based on phase-change material, here Ge2Sb2Te5, allowed us to efficiently control the beam propagation length and quality at the global telecommunication bands (lambda approximate to 850 nm and lambda approximate to 1550 nm). Employing both finite-difference time-domain and finite element method as numerical tools, we accurately computed the critical components of the proposed multifunctional plasmonic light carrier. We believe that the tailored subwavelength optical waveguide paves new approaches to develop practical advanced next-generation nanophotonic technologies.