Plasmonic Waveguides and Interconnects

A. Thomas, A. Dhawan
Indian Institute of Technology-Delhi, IN

Keywords: nanoparticles, localized surface plasmons, long range plasmons, FDTD, interconnects, waveguides

Summary:

One dimensional array of metallic nanoparticles can act as a short range waveguide by coupling of electromagnetic energy through the nanoparticles. As the light of resonant wavelength incident on the metallic nanoparticle, it can excite a localized surface plasmon around the nanoparticle. These Localized Surface Plasmon (LSP) fields are enhanced fields and can couple to the neighboring nanoparticle within the near field region. The coupling mechanism is sensitive to the gap between the nanoparticles, size of the nanoparticles and also depends on the background refractive index. Using FDTD method, we studied the effects of different gaps, diameters and background indices. For long range wave guiding applications, thin metal stripe waveguides as well as waveguides with multiple metal-dielectric interfaces were analyzed. When the thickness of the metal stripe is decreasing, surface plasmon waves generated at each metal-dielectric interface couple together to form symmetric and anti-symmetric modes. Analytical and FDTD studies of modes in single metal-dielectric interface and multiple metal-dielectric interfaces are carried out. Moreover, gold nanolines over a continuous gold film with dielectric layer between them can localize electromagnetic field in the dielectric layer and are being evaluated in our work.