Far-Field Super-Resolution Imaging of Nano-transparent Objects by Hyperlens with Plasmonic Resonant Cavity

A plasmonic resonant cavity-based hyperlens is theoretically proposed and demonstrated to achieve far-field phase contrast images of nano-transparent objects. The phase contrast super-resolution imaging is mainly contributed to the excited surface plasmons inside hyperlens and cavity structure surrounding nano-objects, which help to greatly enhance evanescent waves generated by nano-transparent objects and convert weak phase information to light intensity distribution with high contrast at the zoomed imaging plane of hyperlens. As examples, nano-dielectric object imaging is numerically demonstrated with half-pitch resolution about λ/10 and a minimum distinguishable refractive index difference down to 0.15.