Evolution of optical Tamm states in a 1D photonic crystal comprising a nanocomposite layer for optical filtering and reflecting purposes

Abstract

In this study, the reflection properties of a one-dimensional dielectric photonic crystal covered with metallic (Ag), and nanocomposite layers were investigated theoretically in visible and near-infrared ranges. The reflection spectra for the normal incident electromagnetic waves were calculated using the transfer matrix method. The optical properties and the effective permittivity of the nanocomposite layer were computed based on the Maxwell–Garnett model. The main target of this research is focused on how the intensity and number of the resonant Tamm plasmon modes can be significantly controlled based on the characteristics of the nanocomposite material. Herein, the numerical results clarify the localization of Tamm plasmon resonance states through the reflectance spectrum of our designed structure. In addition, such resonance is significantly improved by attaching a nanocomposite layer between the Ag layer and PC structure. The effects of the radius of the Ag nanoparticles, the thickness of the nanocomposite layer, and the refractive index of the host dielectric material on the reflection spectra of the proposed structure were discussed. Besides, increasing the radius of Ag nanoparticles through the nanocomposite layer leads to an enhancement in the absorption values of the incident light. Finally, we think the proposed structure could be useful in many optical devices, such as optical switches, sensors, back mirrors for solar cells, and multichannel filters.