Magneto‐Optical Metamaterials: Nonreciprocal Transmission and Faraday Effect Enhancement

Abstract Magneto‐optical effects are at the heart of modern technologies providing opportunities for polarization control in laser physics and optical communications, metrology, and in high‐density data storage. Here a new type of a hyperbolic magneto‐optical metamaterial based on Au–Ni nanorod arrays is developed. The metamaterial exhibits an enhanced magneto‐optical response with large rotation of the polarization plane and nonreciprocal light transmission. The effective medium model that incorporates both plasmonic and magneto‐optical phenomena in complex multicomponent nanorod media is proposed and validated. The experimental and theoretical results indicate that the magneto‐optical response of the nanostructured metamaterial is drastically enhanced and spectrally modified with respect to bulk ferromagnetic media due to interplay between strong anisotropy and magnetic field induced polarization rotation.