Coherent perfect absorption in epsilon-near-zero ITO thin film in near infrared

Abstract

Perfect absorption is one of the important application of epsilon-near-zero (ENZ) material. We analyze here the coherent perfect absorption (CPA) in single and bilayer of ENZ thin film of ITO by admittance matching method. To enhance the absorption, a coupling layer of dielectric is to deposit on the substrate with an ENZ ITO layer. CPA conditions are presented here in simulation results which are obtained for p-polarized light. This mode is comparable with the transverse resonance effect. In order to obtain the symmetric results, the optimum polarization direction of illumination is also extracted here. Employing the ENZ CPA property of ITO, this structure is applicable in optical switching, modulation and sensor at the telecommunication regime.