Band gap splitting and average transmission lowering in ordered and disordered one-dimensional photonic structures composed by more than two materials with the same optical thickness

The optical properties of photonic structures made with more than two materials are very interesting for optical filtering and lighting applications. Herein, we compared the transmission properties of one-dimensional photonic crystals made with three, four and five materials, showing that, with a photonic crystal made of t different materials, the band gap splits in t-1 bands. The same optical thickness for the different materials layers results in split photonic band gaps with the same intensity. Photonic crystals with more than two materials are simple structures that could be used for multi-feature optical filters, or that could provide feedback for multi-peak distributed feedback lasers. Furthermore, we analysed the transmission properties of ternary and quaternary random photonic structures. These materials could very interesting for light trapping in photovoltaic devices.