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Layered semiconductor hyperbolic metamaterials (HMMs) are composite materials composed of alternating subwavelength-doped (metal) and undoped (dielectric) semiconductor layers. These materials support the propagation of light with large wave vectors through modes called volume plasmon polaritons (VPPs). In this paper, we use finite-element modeling and effective medium analysis (EMA) to investigate how the number of periods, the period thickness, and the overall HMM thickness affect the VPP mode-resonant wavelengths. We show that the overall HMM thickness has a larger impact on shifting the resonant wavelengths of the VPP modes than the subwavelength structure. We also show that the main limitation of EMA for this application is an inability to account for the boundary conditions at the substrate.

Polar dielectrics are key materials of interest for infrared (IR) nanophotonic applications due to their ability to host phonon‐polaritons that allow for low‐loss, subdiffractional control of light. The properties of phonon‐polaritons are limited by the characteristics of optical phonons, which are nominally fixed for most “bulk” materials. Superlattices composed of alternating atomically thin materials offer control over crystal anisotropy through changes in composition, optical phonon confinement, and the emergence of new modes. In particular, the modified optical phonons in superlattices offer the potential for so‐called crystalline hybrids whose IR properties cannot be described as a simple mixture of the bulk constituents. To date, however, studies have primarily focused on identifying the presence of new or modified optical phonon modes rather than assessing their impact on the IR response. This study focuses on assessing the impact of confined optical phonon modes on the hybrid IR dielectric function in superlattices of GaSb and AlSb. Using a combination of first principles theory, Raman, FTIR, and spectroscopic ellipsometry, the hybrid dielectric function is found to track the confinement of optical phonons, leading to optical phonon spectral shifts of up to 20 cm⁻¹. These results provide an alternative pathway toward designer IR optical materials.

Semiconductors such as InAs with high dopant concentrations have a variety of applications, including as components of mid-infrared optoelectronic devices. Unfortunately, growth of these materials by molecular beam epitaxy is challenging, requiring high growth rates and low growth temperatures. We show that the use of a bismuth surfactant improves silicon incorporation into InAs while simultaneously reducing the optical scattering rate, increasing the carrier mobility, reducing surface roughness, and enabling growth at higher substrate temperatures and slower growth rates. We explain our findings using microscopic theories of dopant segregation and defect formation in III-V materials.

The group III–V semiconductor photonic system is attractive to photonics engineers because it provides a complete set of photonic components. A plasmonic material that can be epitaxially integrated with the group III–V photonic system will potentially lead to many applications leveraging plasmonics and metamaterials. In this work, the shortest plasma wavelength ever reported in a III–V‐based material is demonstrated by epitaxially embedding ErAs into GaAs. This composite material acts as a tunable plasmonic material across the technologically important 2.68–6 µm infrared window. The growth window of this material is demonstrated to be much wider than other current heavily doped III–V plasmonic materials. Additionally, it is shown that the scattering rate can be reduced by increasing the growth temperature. The wide growth temperature range, designer plasmonic response, and the ease of epitaxial integration with other III–V semiconductor devices demonstrate the potential of ErAs:GaAs nanocomposites for the creation of a new type of metamaterial and other novel optoelectronic and nanophotonic applications.