Through the (conducting) looking-glass: transparent conducting oxides for nanophotonic applications (Conference Presentation)

Transparent Conducting Oxide (TCO) materials are degenerately-doped, wide-bandgap semiconductors which exhibit simultaneous high-conductivity and visible transparency. These unique properties are well known and frequently exploited for technologies such as touch-screen devices. In recent years, TCOs have been recognized as a promising material platform for nanophotonic devices, namely because of their simple, compatible fabrication, low-losses, dynamic modulation, and novel low-index properties. In this talk, I will highlight recent progress in the field of TCO-based nanophotonics, share our ongoing results and observations, and discuss future research challenges and directions. In particular, I will discuss our progress in developing metal-dielectric hybrid metasurfaces which incorporate TCOs for all-optical, ultrafast switching. Here, we incorporate defect-rich zinc oxide with a refractory titanium nitride metasurface for efficient light modulation at near-terahertz switching frequencies. My talk will also focus on TCO films for studying and observing low-index phenomena. Our recent work with aluminum-doped zinc oxide films demonstrates the ability for low-index materials to both enhance negative refraction and engender strongly coupled plasmonic systems with large room-temperature Rabi frequencies. Our work signifies the strong potential for incorporating transparent conducting oxides into plasmonic and nanophotonic devices to provide advances toward practical technologies and depth in scientific understanding.