Engineering of metallic nanorod-based hyperbolic metamaterials for broadband applications operating in the infrared regime

Metamaterials are manmade structures that have attained considerable attention over the past 2 decades in the modern fields like cloaking, sensing, and imaging owing to their ability to harness electromagnetic fields. In this regard, we have inspected the dielectric properties of the hyperbolic metamaterials (HMM) made of metallic nanorods and dielectric medium at the infrared wavelength regime. The periodically arranged subwavelength-sized metallic nanorods embedded in the silicon dioxide ( $$\text{SiO}_2$$ ) substrate glass. The spacing between two adjacent nanorods is of subwavelength in size. Furthermore, effective permittivity of the metamaterial has been analyzed by employing the Maxwell Garnett effective medium theory. Moreover, different metallic nanorod inclusions (Au, W, Pt and Ti) were taken into account. Hyperbolic features of the metamaterial have been observed, and it is noticed that hyperbolic features merely depend on the type of metallic nanorods and their size. The observations reveal that the dielectric properties of the metamaterial can be tuned by altering the radii of the metallic nanorod. Apart from dispersion, reflection, transmission and absorption features of the HMM are taken into account. It is noticed that reflection, transmission and absorption of the HMM depend on the type of metallic nanorod and its dimension. Such HMMs structures with exotic dielectric features would be useful for sensing, filtering, and absorption applications.