Spinoptics: Spin-based plasmonics in Nanostru

A study was conducted to demonstrate the spin-dependent behavior of surface plasmon-polaritons (SPP) that resulted from a geometric Berry phase. The investigations revealed that the SPPs were found experimentally, while exploring the interaction of light with metallic anisotropic and inhomogeneous nanoscale structures. The proposed anisotropic inhomogeneous plasmonic structure was produced on top of a thin metal film evaporated onto a glass plate. It was found that the element consisted of a spiral Bragg grating with a central defect surrounded by a coupling grating. The intensity in the plasmonic cavity was measured by a near-field scanning optical microscope (NSOM), and it was observed that the measured intensity distribution exhibited a strong dependence on the incident spin in the SPP. The origin of the spin-dependent change in the near-field intensity distributions in the geometric phase of the excited plasmonic mode was investigated.