Functional Materials with Magnetoelectric Couplings and Gyrotropy

Negative refraction in microwave region have been achieved by requiring two appropriate resonances in the same frequency range. To date, most of the experimental results concerning NIM are in the microwave frequency range, with only a few preliminary results of NIMs available at sub-mm wave and infrared frequencies. The impact of negative index media would be much larger if one can realize negative refraction at optical frequencies. An alternative approach to achieve backward waves and negative refraction at optical frequencies is proposed via magnetoelectric couplings. The gyrotropy effects of those couplings are also examined and potential applications are discussed