Progress in far-field focusing and imaging with super-oscillation

Abstract

Superoscillation is known as a counter-intuitive property of a band-limited function that oscillates faster than its highest Fourier component in a prescribed interval. Based on superoscillation, micro/nano optical devices, breaking through the diffraction limit in the far-field independent of evanescent waves, have potential applications, including super-resolution, nano-photolithography, high-density optical storage, etc. In this paper, superoscillation is introduced simply, and several optical superoscillatory designs with focusing and imaging abilities are summarized primarily, and some defects and future research emphases in these designs are pointed out.