Volume plasmon polaritons in semiconductor hyperbolic metamaterials

Abstract

Layered hyperbolic metamaterials are able to support bulk modes with wavevectors much larger than light in free space. These modes are the foundation of many proposed metamaterial devices. In this paper, we present experimental data measuring the dispersion relationship of these modes in infrared semiconductor hyperbolic metamaterials. The metamaterial optical properties are modeled by taking into account the functional form of the carrier density in the sample due to conduction band bending and the non-parabolicity of the effective mass. In two different samples, we observe multiple volume plasmon polariton modes, and the mode dispersion is traced out by using grating couplers with multiple periodicities. We close by discussing ways to improve these materials.