Subdiffraction Confinement in All-Semiconductor Hyperbolic Metamaterial Resonators

Abstract

The strong optical anisotropy of hyperbolic metamaterials has enabled remarkable optical behavior such as negative refraction, enhancement of the photonic density of states, anomalous scaling of resonators, and super-resolution imaging. Resonators fashioned from these optical metamaterials support the confinement of light to dimensions much smaller than the diffraction limit. These ultrasmall resonators can be used to increase light–matter interactions for new applications in photonics. Here, we present subdiffraction mid-infrared resonators based on all-semiconductor hyperbolic metamaterials. Importantly, these resonators are fully compatible with epitaxial growth techniques and can be engineered to incorporate quantum well intersubband transitions that are degenerate with the mode of the resonators, enabling an entirely new generation of quantum optoelectronic devices. The strongest optical confinement achieved is λ/33 for a free-space wavelength of 10 μm, and the measured Q-factors are in the range of ...