We investigated the field enhancement properties of optical resonant Archimedean spiral antennas by using a finite difference time domain method. Due to the spiral structure, the antennas show a circular dichroism in the electric field enhancement, especially for a large turning angle. A large magnetic field enhancement is also obtained with a confinement in the nanometer size. When the turning angle equals π for a linearly polarized incident beam, the polarization of the enhanced field in the spiral antenna can be perpendicular to the incident polarization with a similar enhancement factor to the optical resonant dipole antennas.
We propose a shift multiplexing method for a compact holographic volume storage system by using planar waveguide referencing. In the method, a planar waveguide is used to steer the reference beam and shift multiplexing is implemented by shifting the recording medium. We measure the diffraction efficiencies with respect to the shift distance of the medium for different widths of the waveguide. The selectivity of the storage system can be about 1.0 μm when the width of the waveguide is 0.05 mm. Multiple holograms are stored with a spatial separation of 2.5 μm. By using the planar waveguide, a high storage density can be achieved. As the planar waveguide is already commonly used in integrated optical systems, the whole storage system can become more compact and simpler.
Conference Committee Involvement (2)
Nanophotonics, Nanostructure, and Nanometrology II