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Optimal plasmonic focusing can be achieved through matching the rotational symmetry of the plasmonic lens to the polarization symmetry of a radially polarized illumination. In this letter, we report the experimental confirmation of the focusing properties and field enhancement effect of plasmonic lens made of multiple concentric annular rings using a(More)
A spiral plasmonic lens can focus circular polarization of a given handedness while simultaneously defocus the circular polarization of the opposite chirality, which may be used as a miniature circular polarization analyzer. In this letter, we experimentally investigated the plasmonic focusing properties of the spiral lens using a collection mode near-field(More)
We report the experimental confirmation of the evanescent Bessel beam generation via surface plamson resonance excitation with a radially polarized beam. The interference of surface plasmon waves excited by a radially polarized beam creates an evanescent Bessel beam with enhanced localized field and spot size beyond the diffraction limit. The excitation of(More)
We report a new method to create high purity longitudinally polarized field with extremely long depth of focus in the focal volume of a high numerical aperture (NA) objective lens. Through reversing the radiated field from an electric dipole array situated near the focus of the high-NA lens, the required incident field distribution in the pupil plane for(More)
An axially symmetric three-dimensional finite element method model is applied to investigate the electromagnetic field distribution in the vicinity of a silver coated glass tip. Under radially polarized illumination, a strongly enhanced field located at the apex of the tip is found due to the constructive interference of surface plasmon propagating at the(More)
A simple spiral plasmonic lens is studied both analytically and numerically. Owing to the geometric phase effect, a spiral plasmonic lens focuses the left-hand and right-hand circular polarizations into spatially separated plasmonic fields. Such a spatial multiplexing of the field distribution is utilized in miniature circular polarization analyzer design.(More)
We propose an approach to obtain a diffraction-limited spherical focal spot in 4Pi microscopy. By combining the dipole antenna radiation pattern and the Richards-Wolf vectorial diffraction method, an input field at a pupil plane of aplanatic objective lenses for generating a spherical spot can be found analytically by solving the inverse problem. The(More)
Coupling nanoscale emitters via optical antennas enables comprehensive control of photon emission in terms of intensity, directivity and polarization. In this work we report highly directional emission of circularly polarized photons from quantum dots coupled to a spiral optical antenna. The structural chirality of the spiral antenna imprints spin state to(More)
The spin dependence of the focusing behavior of a spiral slot plasmonic lens can be utilized for a miniature circular polarization analyzer. However, the azimuthal polarization component of the incident circular polarization does not contribute to surface plasmon excitation and focusing because it is TE polarized with respect to the spiral slot. In this(More)
The spiral plasmonic lens is capable of focusing the left-hand and right-hand circular polarizations into spatially separated plasmonic fields caused by the geometric phase effect. Its function as a circular polarization analyzer has been studied analytically and numerically in a previous Letter [Opt. Lett.34, 3047(More)