Optical filters based on fixed length Thue–Morse plasma-dielectric photonic band multilayers: Comparing two, three, and four materials systems

In this paper, we study the optical filtering properties of plasma-dielectric photonic crystals based on Thue–Morse multilayers. The method of generating the Thue–Morse sequence used in the current paper is different from that used in the available literature. We fix the total multi-material system length and use two, three, and four alternative layers of materials with different refractive indices to study the optical transmission properties of a few proposed structures. We also use plasma layers to have more tunable bandgaps. We employ the transfer matrix method to do our numerical calculations. We change the geometrical parameters, the number of layers, the arrangement of the layers, material refractive indices, and plasma properties and extract their effects on the bandgap behavior. We determine the tunability of the proposed structures to facilitate the selection of the one with desired filtering properties. However, understanding the tunability of our systems can facilitate the devising of optical devices such as an optical filter.