Defect mode and bandgap properties of a ternary photonic crystal with a nanocomposite defect layer

A one-dimensional ternary photonic crystal with a defect layer is investigated. It has the structure of silicon dioxide/silicon nitride/polystyrene (SiO2/Si3N4/(C8H8)n). A nanocomposite layer composed of silica and silver nanoparticles is placed at the middle of the photonic crystal as a defect layer. The transmission spectra of s-polarized (TE) and p-polarized (TM) waves through the photonic crystal are studied. The defect mode and the bandgap are both examined with the variation of the defect layer thickness, the number of periods, the filling factor of the silver nanoparticles in the nanocomposite and the angle of incidence. The results show that the number of defect modes and their wavelength positions are strongly dependent on the defect layer thickness and the filling factor. This is a significant phenomenon for potential applications of the photonic crystal as a multi-channel filter.