Canalization of subwavelength images by electromagnetic crystals

TLDR

Flat superlenses based on electromagnetic crystals operate without negative refraction or evanescent‑wave amplification, unlike perfect lenses from left‑handed media. The authors propose a new operating regime for flat superlenses formed by electromagnetic crystals. They canalize the subwavelength spatial spectrum through crystal eigenmodes with identical longitudinal wave‑vector and group‑velocity components, implemented at low frequencies using capacitively loaded wire media. The device achieves λ/6 resolution and its thickness is independent of source distance, allowing arbitrarily thick lenses.

Abstract

The original regime of operation for flat superlenses formed by electromagnetic crystals is proposed. This regime does not involve negative refraction and amplification of evanescent waves in contrast to the perfect lenses formed by left-handed media. The subwavelength spatial spectrum of a source is canalized by the eigenmodes of the crystal having the same longitudinal components of wave vector and group velocities directed across the slab. The regime is implemented at low frequencies with respect to the crystal period by using capacitively loaded wire media. The resolution of $\ensuremath{\lambda}∕6$ is demonstrated. The thickness of the superlens is not related with the distance to the source and the lens can be made thick enough.