  In this paper, the characteristic matrix method is employed to theoretically
investigate the propagation of electromagnetic waves through one-dimensional
defective lossy photonic crystals (PCs) composed of negative index materials
(NIMs) and positive index materials (PIMs). We consider symmetric and
asymmetric geometric structures with two different types of NIM defect layers
at the center of the structure. The effects of the polarization and the angle
of incidence on the defect modes in the transmission spectra of both structures
are investigated. The results show that the number of the defect modes within
the photonic band gap (PBG) depends on the type of the NIM defect layer and is
independent of the geometrical structure. Moreover, it is shown that the defect
mode frequency increases as the angle of incidence increases. This property is
also independent of the geometry of the structure. The results can lead to
designing new types of narrowband and multichannel transmission filters.
