Polarization-dependent zero-plasma-permittivity, zero-permittivity, and zero-permeability gaps in a 1D photonic crystal composed of lossy double-negative and magnetic cold plasma materials

Abstract

Theoretically, we have employed a transfer matrix to examine the tunable band structure and transmission properties of a one-dimensional photonic crystal that consists of periodic layers of a lossy double-negative index and magnetic cold plasma materials. Our study shows that the existence of unconventional photonic bandgaps (PBGs) is due to the material dispersion properties of double-negative and magnetic cold plasma layers and fundamentally differs from Bragg gaps, which arise due to an interference mechanism. The two new gaps, called zero-permittivity ( ε = 0 ) and zero-permeability ( μ = 0 ), near the frequency at which the permittivity and permeability of double-negative material change signs, have been found for non-zero incidence angles corresponding to p and s polarizations, respectively. These gaps can be easily tuned as well as enlarged by the application of an external magnetic field in both right-hand and left-hand polarization configurations. At a fixed magnetic field, ε = 0 and μ = 0 gaps corresponding to p and s polarizations, respectively, can be further enhanced by increasing the angle of incidence to higher values. Additionally, we have found a tunable zero-plasma-permittivity ( ε P = 0 ) gap close to the frequency at which the magnetic-field-dependent electric permittivity of a cold plasma layer changes sign at a non-zero incident angle corresponding to p polarization only. Finally, we present a way by which the zero-effective-phase gap, ε = 0 gap, and ε P = 0 gap can be joined together to produce an enlarged PBG at a non-zero incidence angle corresponding to p polarization only in the presence of an external magnetic field of value B L = 0.473 T . The proposed study may be used for designing of polarization triggered tunable optical devices in microwave engineering applications.