Noncoplanar Optical Bow-Tie Shaped Nanoantenna and Array for Near-Field Enhancement

In this paper, a new form of noncoplanar optical bow-tie shaped nanoantenna structure is proposed, analyzed, and further arranged in array to investigate their near-field enhancement properties. The noncoplanar design not only improves the near-field electric field enhancement performance by 33% compared with that of the coplanar form, but also achieves better compatibility with subsequent conversion circuit by providing appropriate process tolerance. In particular, the array is designed by collecting the convergence of enhanced near-field from each unit to a fixed point for observation conveniently. By adopting the 16-element array composed of noncoplanar configuration, the strongest electric field strength can reach as high as 210 V/m, while that is 33.6 V/m for the conventional bow-tie shaped nanoantenna. Moreover, the field enhancement bandwidth has been broadened.