Improving resolution of superlens based on solid immersion mechanism

Abstract

Super-resolution imaging with superlens has been one of the fundamental research topics. Unfortunately, the resolution of superlens is inevitably restrained by material loss. To address the problem, we introduce the solid immersion mechanism into the slab superlens and the cylindrical superlens. The proposed solid immersion slab superlens (SISSL) and the solid immersion cylindrical superlens (SICSL) can improve the resolution by converting evanescent wave to propagating wave using high refractive index materials. From the perspective of applications, the cylindrical superlens with finite cross section and the ability of magnification or demagnification has more advantages than the slab superlens. Therefore, we focus on demonstrating analytically the super-resolution imaging of SICSL. Due to the impedance mismatching caused by solid immersion mechanism, the whispering gallery modes (WGMs) are excited between SICSL and the air interface. We clarify the excitation conditions of WGMs and analyze their influence on the imaging quality of SICSL. The SISSL and SICSL may pave a way to apply in lithography technique and real-time biomolecular imaging in future.