Far-field subwavelength imaging by harnessing the single-mode resonance and sparsity

Abstract

Although far-field superlenses and resonant metalenses provide a way to obtain the far-field subwavelength imaging through the resonant excitation of multiple surface wave modes, the high sensitivity of these resonant modes to the absorption loss hinders their practical applications. To break this limitation, only a single resonant mode which survives the absorption loss is chosen for imaging, where a reconstruction algorithm based on the sparsity is adopted to compensate for the reduction of the number of degrees of freedom. An experiment is carried out to verify a far-field subwavelength imaging of two home-made sources, and it is found that the two imaged sources can be well resolved by using multiple frequencies near the fifth resonant mode.