Mid-Infrared waveguides and negative refraction with anisotropic metamaterials

We propose two metamaterial waveguides, operating in the mid-IR, which would display negative refraction. The first waveguide is a metallic strip incorporating quantum wells, whereas the second is a dielectric waveguide which incorporates quantum wells. The negative refraction of both waveguides occurs around the intersubband transition (ISBT) of the quantum wells and is dependent upon the 2D concentration of electron within the wells; these materials could be grown by conventional semiconductor technology (MBE) and the electron concentration within the wells controlled externally by electric fields or optically pumping.