Mid-infrared Excitation of Plasmonic Resonances in Highly Anisotropic Layered Semiconductor Structures

Abstract

We fabricate degenerately doped quantum well superlattices and highly doped n+‐i‐n+ heterostructures and examine their optical anisotropy. We demonstrate that the n+‐i‐n+ metamaterial has sufficient anisotropy to exhibit negative refraction over a wide range of incident angles and wavelengths. Further, we show that the interval of high anisotropy, and thus negative refraction, can be controlled through the doping density in the structures.