Investigation and comparative analysis of zero-n gap characteristics and defect mode tunability in a metamaterial-based binary photonic crystal

In this paper, we make an analysis, of zero-n gap in a one-dimensional metamaterial based photonic crystal having a periodic structure comprised of Boron Nitride and metamaterial and a defect layer of Silica, with the help of transfer matrix method. We focus on zero-n gap, mid-frequency and tunability of an induced defect mode in broadband. It is found that the zero-n gap lies in the DNG region of the metamaterial and is independent of angle variation in both TE and TM modes and is in good agreement with already reported results. It is noted that the position or mid-frequency of zero-n gap is tunable with the metamaterial thickness and independent of the defect thickness, while the zero-n gap remains almost same in both cases contrary to Bragg gap, where the defect mode frequency is toggling with defect thickness. So with these properties, the insights of this extensive analysis for such a metamaterial based PC may be applicable in designing optical devices, viz. sensors, filters, and switching devices.