Computation of Electromagnetic Bandgap in Two-Dimensional Photonic Crystal
Rapid progress in application of electromagnetic wave propagation inside the guided media results the physical realization of photonic crystal (PhC) structure, whose unique features of restricting and controlling the direction of electromagnetic wave finds relevance in the advancement of microwave photonics. EBG structures have already found wide applicability in antenna design, as well as engineering all-optical components for photonic integrated circuits. In this context, it becomes very important to understand and cultivate the fundamental properties of PhC, and that begins with the realization of bandgap. Among different PhC structures, 2D is studied a little less, due to the complex mathematical formulation, as well as its difficulty from a fabrication point of view. Though rectangular PhC structure with two-dimensional configuration is studied a little, but comparative study with triangular constitution requires demand from the point of view of tailoring photonic bandgap in a more efficient manner, simultaneously having the added advantage of midband frequency variation higher than the rectangular structure. In the present chapter, based on the plane wave method, photonic bandgap for both rectangular and triangular geometries have been studied with a focus on midband frequency and bandgap variations, tuned by material compositions and dimensions of the arrangement, even in presence of polarized incidence of electromagnetic waves. Results will play a key role in designing PhC based optical filter design.