ABSTRACT
An optical metamaterial (MM) is an artižcially engineered composite with electromagnetic properties that are determined by subwavelength structuring rather than by the constituent materials. Hence, when rationally designed, metamaterials can demonstrate electromagnetic properties that are unattainable with naturally occurring materials. By changing the design of the unit cell or “meta-atom,” the optical properties of the metamaterial can be tailored; for example, the values of permeability, μ, and permittivity, ε,
2.2 First Experimental Demonstrations: Single Metamaterial Layer................................................. 33
2.5 Œin Metal Film Deposition .................................48 2.6 Discussion ................................................................ 49
can be controlled. For example, one of the properties that cannot be observed in natural materials is a negative refractive index (demonstrated in negative index metamaterials, or NIMs) (Veselago 1968; Pendry 2004; Veselago et al. 2006; Veselago and Narimanov 2006; Soukoulis, Kafesaki, and Economou 2006; Shalaev 2007; Soukoulis, Linden, and Wegener 2007). Œe limitations of the attainable optical responses of naturally occurring materials are imposed by their material properties that are in turn determined by their unit cells-atoms and molecules. By using artižcially structured metamaterials, meta-atoms can be designed to exhibit specižc electric and magnetic responses in a required frequency range.
