Design and analysis of multichannel trans- mission filter based on the single-negative photonic crystal

In this work, the multiple filtering phenomenon in a photonic crystal made of single-negative (SNG) materials is investigated. We consider a finite photonic crystal (AB)N immersed in air, in which A, B are epsilon-negative (ENG) and mu-negative (MNG) materials, respectively, and N is the stack number. It is found that such a photonic crystal can function as a multichannel transmission filter with a channel number equal to N-1. The required condition is that the thickness of MNG layer must be larger than that of ENG layer when magnetic plasma frequency is greater than electric plasma frequency. The channel frequencies can be red-shifted as the thickness of MNG layer decreases. The channel positions can be tuned by the incidence angle for both TE and TM polarizations. That is, the peak frequency is blue-shifted when the angle of incidence increases. Additionally, the influence of the static permeability of ENG medium and permittivity of MNG medium is also illustrated. The proposed structure can thus be used to design as a tunable multichannel filter which is of technical use in signal processing.