Tunable Dual-band Filter Based on Photonic Crystals Doped by Unmagnetized Plasma

A novel tunable dual-band filter from one-dimensional photonic crystals doped by unmagnetized plasma is analyzed. Two defective PCs composed by ZnSe and Na3AlF6 with one defect layer made by unmagnetized plasma stacked in symmetric geometry are considered. By the transfer matrix method and Bloch's theorem, it is found that the frequency of the defect modes can be modulated by plasma frequency and defect thickness. Without changing the structure of the photonic crystal, the defect modes can be modulated in a larger frequency range. These results may provide theoretical instructions for designing new optoelectronic devices.