A hyperlens-based device for nanoscale focusing of light

Abstract

To resolve the problem of missed evanescent waves in a beam focusing system, a hyperlens-based beam focusing device is proposed in this letter. This device can convert the evanescent waves into propagating waves, and then a super-resolution spot is formed at the center of the hyperlens. The working principle of the device is presented, and the way in which the material and structural parameters of the hyperlens affect the resolution and transmission is analyzed in detail. A multibeam focusing device is optimally designed, and the simulated results verify that a nanoscale spot with a diameter of 15.6 nm (corresponding to \lambda 0/24, where \lambda 0 is the working wavelength in vacuum) is achieved, which is far less than the diffraction limited resolution with a value of 625 nm (1.7\lambda 0). The device is expected to find numerous applications in optical data storage and nano{photolithography, among others.