| 摘要 |
The present invention provides an apparatus for propagating electromagnetic radiation of a selected vacuum wavelength beyond the diffraction limit. The apparatus comprises a waveguide core and a cladding disposed about the core. The waveguide core may include a material with an anisotropic dielectric permittivity, with the optical axis of the material primarily aligned with direction of light propagation. In addition, the waveguide core may have a cross-sectional dimension smaller than about ½ of the selected wavelength at least at one portion of the waveguide core. The cross-sectional dimension of the waveguide core may decrease along the length of the waveguide core creating a taper to provide a photonic funnel. The waveguide core may comprise a homogeneous anisotropic material, anisotropic metamaterial, or a photonic crystal.
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