Local circular polarization observed in surface vortices of optical near-fields.
We demonstrate local circular polarization in surface vortices of an optical near-field generated by superposing two cross-propagating evanescent waves with transverse electric fields on a planar dielectric surface. The circularly rotating local electric fields are converted into circularly polarized propagating light waves in free space via a near-field interaction with a sub-wavelength size local probe. The results show that optical near-fields generated under the influence of a material environment with local rotational symmetry carry angular pseudo-momentum with respect to the symmetry axis. The local circular polarization is of fundamental significance in spin-related and magneto-optical phenomena in nanophotonics.
Department of Electrical and Electronic Engineering, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan. ohdaira@eng.niigata-u.ac.jpt
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Y
Ohdaira
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Inoue
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Hori
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Kitahara
D003198:Computer Simulation; D008027:Light; D008962:Models, Theoretical; D036103:Nanotechnology / Q000379:methods*; D055095:Optics and Photonics; D017785:Photons; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation