Alternative approach to all-angle negative refraction in two-dimensional photonic crystals

TL;DR

This paper introduces a surface modification technique for 2D photonic crystals that enables all-angle negative refraction in new frequency windows, allowing for flat lens imaging of larger or distant objects, confirmed by simulations.

Contribution

It presents a novel surface modification method to achieve all-angle negative refraction in 2D photonic crystals, expanding potential applications in flat lens imaging.

Findings

Negative refraction achieved in new frequency windows

Flat lens imaging with u+v much larger than the lens thickness

Results confirmed by FDTD simulations

Abstract

We show that with an appropriate surface modification, a slab of photonic crystal can be made to allow wave transmission within the band gap. Furthermore, negative refraction and all-angle-negative-refraction (AANR) can be achieved by this surface modification in frequency windows that were not realized before in two-dimensional photonic crystals [C. Luo et al, Phys. Rev. B 65, 201104 (2002)]. This approach to AANR leads to new applications in flat lens imaging. Previous flat lens using photonic crystals requires object-image distance u+v less than or equal to the lens thickness d, u+v d. Our approach can be used to design flat lens with u+v=sd with s>>1, thus being able to image large and/or far away objects. Our results are confirmed by FDTD simulations.