Pyramid-shaped hyperlenses for three-dimensional subdiffraction optical imaging

Based on the hyperbolic dispersion relation for a strongly anisotropic medium, we propose a kind of pyramid-shaped hyperlenses (PSHLs) consisting of multilayer of planar silver and dielectric films for three-dimensional (3D) subdiffraction imaging at optical wavelengths. Numerical simulations by using the finite difference time domain method demonstrate that the PSHLs can resolve eight point sources with nanoscale separations distributed in 3D domain (with different hexahedron structures). Our results imply the potential applications of the hyperlens in real-time biomolecular imaging, nanolithography, and sensing.