Negative refraction and superlensing in a 2D photonic crystal structure

TL;DR

This paper demonstrates negative refraction and superlensing in a 2D photonic crystal with a triangular dielectric array, showing high transmission and evanescent wave reconstruction in the microwave regime.

Contribution

It introduces a novel photonic crystal structure exhibiting negative refraction and superlensing, supported by experimental and theoretical analysis.

Findings

Negative refraction observed in the microwave regime

High transmission over a wide range of incident angles

Surface waves enable evanescent wave reconstruction

Abstract

We experimentally and theoretically studied a new left-handed (LH) structure based on a photonic crystal (PC) with a negative refractive index. The structure consists of triangular array of rectangular dielectric bars with dielectric constant 9.61. Experimental and theoretical results demonstrate the negative refraction and the superlensing phenomena in the microwave regime. The results show high transmission for our structure for a wide range of incident angles. Furthermore, surface termination within a specific cut of the structure excite surface waves at the interface between air and PC and allow the reconstruction of evanescent waves for a better focus and better transmission. The normalized average field intensity calculated in both the source and image planes shows almost the same full width at half maximum for the source and the focused beam.