A new surface plasmon resonator, in the form of a metal cylinder shaped like a teardrop, is proposed and modeled using hypersingular integral equations. Illuminating the apex of the teardrop along its axis of symmetry with TM-polarised light excites equal-magnitude surface plasmons counter-propagating around its periphery. Interference of these counter-propagating surface plasmons leads to resonant modes having very sharp line-widths (~0.6 nm) and large quality factors (~3400). In water, a Au teardrop supports resonant modes having large bulk sensitivities (~1900 nm/RIU) and remarkably large figures-of-merit (~1700), about 1000 × larger than the figure-of-merit of, e.g., isolated Au nano-spheres. The scattering cross-section of the structure near resonant modes exhibits a Fano-like line-shape. The teardrop should find applications as a high-quality surface plasmon resonator or as a biosensing element.

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In this paper we have investigated the performance of a nano-optical power splitter based on gap plasmon waveguides. The structure consists of the rectangular gap plasmon waveguides in metal films. It is clear that the wave number and correspondingly light confinement and the loss in the waveguides are the most effective parameters in power splitting, but as we know coupling length is another important factor which should be considered. Some dependencies of the coupling length and the maximum transfer power on the structure parameters are studied. It has been shown that approximately 43% transfer power for each arm of the splitter is achievable. Simulation results have been obtained by the compact finitedifference time-domain method. The considered structures, because of their small coupling length and dimensions are appropriate for implementation in photonic integrated circuits.

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The behavior of electromagnetic fields near the edge of a plasmonic wedge is investigated. We study the scattering properties, field divergence, and field enhancement near an Au wedge bounded by SiO2 upon illumination by TM-polarized light using hypersingular integral equations, as a function of wavelength, wedge angle, and angle of incidence. The transverse scattered field components show a convergent behavior at wavelengths approaching the surface plasmon energy asymptote (on the corresponding flat Au-SiO2 interface), and become strongly divergent at longer wavelengths. The computed divergence is compared with Meixner's theory and is found to be in good agreement over a restricted range of parameters.