Three-dimensional, arbitrary orientation of focal polarization.
ABSTRACT We demonstrate a simple setup for generating a three-dimensional arbitrary orientation of the polarization vector in a laser focus. The key component is the superposition of a linearly and a radially polarized laser beam, which both can be controlled individually in intensity and relative phase. We exemplify the usefulness of this setup by determining the spatial orientation of a single silver nanorod in three-dimensional space by recording the angle-variable backscattered light intensity.
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ABSTRACT: To obtain an arbitrary polarization in three dimensions is of significant interest for many applications. Here, we demonstrate a configuration to achieve it. After phase coding by binary phase plates, two cylindrical polarized beams are superposed and focused by a high-numerical aperture lens to obtain transversally and radially polarized components in the focus vicinity. By adjusting their intensity and phase difference, the desired three-dimensional polarization can be achieved. The proportion of the desired polarization is extremely high and the focus spot is smaller than the diffraction-limited spot size.Journal of Modern Optics 01/2014; 61(4). · 1.17 Impact Factor