Superlens coupling to object and image: A secondary resonance mechanism to improve single-negative imaging of electromagnetic waves

Abstract

Superlens slabs rely on the coherent superposition of multiply reflected evanescent waves to amplify and restore the fine details of an object at the image plane. If a superlens slab is placed in close proximity to a source object and image detector, similar interactions with these external components can introduce resonances outside of the superlens. In this work, we explore the role of external resonances on single-negative slab superlens performance by considering a complete electromagnetic imaging system containing a physical source object and image detector, each modeled as a planar dielectric half-space. In studying the transmission of spectral components that carry real power through this system, we find that resonances outside the lens can have a dramatic impact on single-negative superlens performance. In particular, we find that the resonances external to a μ-negative lens can be used to extend the imaging range beyond the extreme near field and maintain super-resolution even in the presence of loss.