Localized electromagnetic modes in one-dimensional defective fractal multilayers containing ε-negative and μ-negative metamaterial layers

Tunable defect modes in one-dimensional fractal structures containing ε-negative metamaterials (ENG) and μ-negative metamaterials (MNG) are analyzed with transfer matrix method. By inserting double-positive (DPS) type defect layers in the supposed structure, ENG-DPS-ENG and MNG-DPS-MNG arrangements are considered. It is found that in the ENG-DPS-ENG (MNG-DPS-MNG) arrangement for TE polarization defect modes are sensitive (insensitive) to incident angle while for TM polarization they are invariant (variant). Also, the spectral position of the defect mode is invariant upon the change of scale length. Furthermore, by varying defect layers thicknesses, defect modes shift to the lower frequencies.