1 Department of Photonics Engineering, Technical University of Denmark2 Structured Electromagnetic Materials, Department of Photonics Engineering, Technical University of Denmark3 Center for Electron Nanoscopy, Technical University of Denmark4 Center for Nanostructured Graphene, Center, Technical University of Denmark5 Department of Micro- and Nanotechnology, Technical University of Denmark6 University of Southern Denmark
We investigate the effects of nonlocal response on the surface-plasmon polariton guiding properties of the metal-insulator (MI), metal-insulator-metal (MIM), and insulator-metal-insulator (IMI) waveguides. The nonlocal effects are described by a linearized hydrodynamic model, which includes the Thomas-Fermi internal kinetic energy of the free electrons in the metal. We derive the nonlocal dispersion relations of the three waveguide structures taking into account also retardation and interband effects, and examine the delicate interplay between nonlocal response and absorption losses in the metal. We also show that nonlocality breaks the complementarity of the MIM and IMI waveguides found in the nonretarded limit.
Physical Review B (condensed Matter and Materials Physics), 2013, Vol 88, Issue 11