Abstract

Surface plasmons are collective electromagnetic excitations that propagate at an interface between dielectric and metallic layers, evanescently confined in the direction perpendicular to the interface. The surface plasmon wave is associated with a shorter wavelength than light in free space, and a stronger field enhancement effect near the interface. Because of the shorter effective wavelength, the surface plasmon waves can be focused into a highly confined spot with the scale beyond the diffraction limit, making them very attractive for future photonic applications in many areas such as nano optics¹⁾, super-resolution imaging²⁾, nanolithography³⁾, waveguiding⁴⁾, near-field imaging and sensing⁵⁾.

© 2011 Optical Society of America