Design and modeling of photonic crystal Absorber by using Gold and graphene films

Abstract

A novel absorber based on a one-dimensional photoniccrystal (PhC) is proposed by combining the absorptionproperty of gold and graphene films. We designed twophotonic crystals consisting of silicon and silicondioxide layers with lattice constants 125 and 260 thatalternate in one dimension. We placed a 125-nanometerthicklayer of graphene between the two photoniccrystals and an 8-nanometer-thick layer of gold at theend of the second photonic crystal. When graphene isplaced between two photonic crystals, a topological edgemode excitation creates a strong absorptionenhancement. In this study, the absorbing spectrums andfield distribution are analyzed by using the transfermatrix and the 2.5 dimensional variational finitedifference time domain method (2.5 var.FDTD). Theabsorption spectrum for different angles was studied(θ=0 to 60), and more than 87 percent absorption can bemaintained for θ =40°. The results of our studies willenhance the interaction between light and matter. Thus,opening up the possibility of their application for theabsorption and modulation of light

Keywords

• photonic crystals
• absorber
• gold nanostructures
• graphene