The mid-infrared (mid-IR) spectral range (3-30µm) has become a burgeoning and dynamic field of research both for fundamental exploration as well as for more applied research in health and the environment, security and defense, communication, and sensing. At the same time, the areas of plasmonics and metamaterials have experienced explosive growth over the past decade, fueled in part by rapid developments in fabrication, characterization, computational science, and theory. Yet, the integration of plasmonic structures into mid-IR optical systems has been slower to evolve. While scaling metamaterial and plasmonic geometries to mid-IR wavelengths is actually fairly straightforward, replicating the near-IR and visible optical properties of constituent materials in plasmonic and metamaterial systems is less trivial, leading to very different behavior of scaled systems in these two wavelength ranges.
In this talk, I will discuss our group’s recent work developing novel optoelectronic and plasmonic devices and structures for mid-IR applications. I will demonstrate the advantages and disadvantages of utilizing traditional plasmonic metals in mid-IR structures, and use this discussion to motivate our recent work with highly doped semiconductors as designer mid-IR metals for plasmonic, metamaterial, and epsilon-near-zero applications. In particular, I will focus on the promise of these new plasmonic materials for nano-scale confinement of micron-scale wavelengths, and for potential applications in sensing, thermal emissivity control, and integration with new types of mid-IR optoelectronic devices. Results demonstrating all-semiconductor perfect absorbers and nano-antennas, as well as hybrid plasmonic/optoelectronic devices will be presented. Finally, I will discuss how our advances in mid-IR photonic and optical materials can be leveraged to explore the forbidding world of far-IR optics.