Multichannel tunable polarizing filter properties of one-dimensional ternary photonic crystal containing single-negative materials

Angle and polarization-dependent tunable transmission properties of a one-dimensional (1D) ternary photonic crystal (TPC) whose period consists of three alternate layers of two different kinds of single-negative [Epsilon-negative (ENG) and mu-negative (MNG)] media are theoretically investigated by using the transfer matrix method (TMM). It has been shown that the proposed polarizing filter is capable of transmitting multiple polarized transmission peaks (called as channels) by adjusting the incident angle from 21° to 89° as per need. The resonant frequencies of these respective transmission channels are completely different for the case of TE and TM polarizations. The proposed structure contains only twelve SNG material layers corresponding to the period number N = 4. This structure filters 18 separate transmission channels for TE and TM waves each at incident angle θ0=21∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \theta_{0} = 21^{\circ} $$\end{document}. The number of polarization dependent channels can be further increased to 35 and 37 for TE and TM polarizations, respectively, when the period number of 1D TPC increases from 4 to 8 at θ0=89∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \theta_{0} = 89^{\circ} $$\end{document}. This eight-period 1D TPC structure requires only 24 SNG material layers. The effect of lossy SNG materials on the performance of the filter is also investigated. This study may find its application in the field of optical communication for accommodating a large number of optical channels in the same bandwidth. Such types of filters may have their applications in integrated optics for dense wavelength division multiplexing systems and ultrafast light information processing.