Numerical results for the distributions of light transmitted through metallicplanar lenses composed of symmetric nanogroove arrays on the surfaces of a goldfilm are presented and explained. Both the near- and far-field distributions ofthe intensity of light transmitted are calculated by using a Green's functionformalism. Results for an optimal transverse focus based on a quadraticvariation of groove width are obtained. Meanwhile, a significant dependence ofthe focal length on the wavelength of light incident from the air side throughthe gold film into a dielectric substrate is found for this detectorconfiguration.
展开▼