Tunable Nonlinear Meta-Absorber Based on Epsilon-Near-Zero Metamaterial

We propose a tunable metamaterial absorber based on a epsilon-near-zero (ENZ) material with a large optical nonlinearity. We show that the absorption efficiency of the metamaterial can be dynamically controlled by changing the incident intensity. Moreover, we demonstrate that a hybrid metamaterial, composed of ENZ material and dielectric material, exhibits nonreciprocal absorption due to the broken spatial inversion symmetry and the large optical nonlinearity of ENZ material. Changing the intensity of incident beam, one can tune the absorption efficiency of hybrid metamaterial from 50% to 90%. Our study provides a novel approach toward ultrafast dynamical control of the absorption efficiency of metamaterial for such applications as microbolometers, thermal imaging, harvesting, scattering reduction, photodetection, and stealth technologies.