Funneling of Oblique Incident Light through Subwavelength Metallic Slits

Abstract

Light funneling determines how enhanced energy flows into subwavelength slits. In contrast to the previous research on oblique incident light, this study reveals that light funneling in the slits can be highly asymmetric, even at small angles. This mechanism is explained by polarized fields and charges, which are induced using Poynting vectors. It is shown that when light is obliquely incident to the slits perforated in a perfect electric conductor, asymmetrical fields and charges accumulate at the upper apex corners of the left (right) sides. When light is incident from the left (right) side, more (less) induced fields and charges accumulate in the left (right) slit corner so that the funneling width, area, and energy flow at the left (right) side increases (decreases).

Ultrafast Dynamics of Extraordinary Optical Transmission through Two-Slit Plasmonic Antenna

“…Physically, surface plasmon and cavity mode resonances, known as Fabry–Perot (FP) resonance, play a dominant role in the formation of EOT. Most previous research focuses on investigations of the static-state modes of EOT in terms of geometry, size, and the composition of nanostructured materials, as well as the wavelength and polarization of the incident light [ 11 , 12 , 13 , 14 , 15 , 16 ]. However, as for the dynamic behavior of EOT, it is currently an ongoing topic for exploring the potential capability to actively and flexibly manipulate the EOT in spatial-temporal regimes [ 17 ].…”