Back Cover: Negative refraction in anisotropic metamaterials (Phys. Status Solidi B 6/2012)

As shown by Prieto‐López and Barrera (pp. 1110–1118), highly anisotropic metamaterials can be used to construct simple and efficient diffuse‐light refractive collimators. ‐ Decades have passed since the first theoretical studies about negative refraction appeared, but the topic has never been so active. Experimental efforts to achieve this phenomenon and the consequent design of metamaterials have allowed to consider many possibilities that natural materials restrict. This has also required reconsidering and generalizing the analysis of problems that were believed to be fully understood and characterised. In particular the optics of crystals ‐ anisotropic linear materials ‐ has interesting behaviors that do not occur when the analysis begins assuming absent magnetic response and restricted dielectric response. These materials have, among other features, negative refraction with only one of its material properties negative, transmission of light with imaginary index of refraction, the possibility of being anti‐reflective, and an interesting limit that allows the proposal of a diffuse‐light refractive collimator.