Figure 3

Dielectric functions of type I and type II hyperbolic metamaterials. (a) Real and (b) imaginary parts of the dielectric functions of gold nanorod arrays embedded into the Al₂O₃ host (p = 0.3). (c) Real and (d) imaginary parts of the dielectric functions of a silver-silica lamellar structure (f _m  = 0.5). In the overlapping spectral range 575–900 nm, both type I and type II HMMs are realizable. Green dashed lines separate the positive and negative values of the real parts of the dielectric functions.