Gold-silicon metamaterial with hyperbolic transition in near infrared

Abstract

In this paper, we focus on the creation and characterization of a hyperbolic metamaterial for near infrared. To shift the hyperbolic transition there, a stack of alternating 7 nm gold and 42 nm silicon layers is chosen. Samples are manufactured using magnetron sputtering and different measurements confirm their structure. We fit the Drude model of gold to reproduce measured reflectivity and transmittance by simulations. The collision frequency of the thin film gold is increased by 9 times, which shifts the transition of our metamaterial to the hyperbolic regime to even larger wavelengths. The performance is comparable to other proposed metamaterials.