Abstract: | Metasurfaces have shown their unprecedented capability to manipulate the amplitude, phase, and polarization state of the electromagnetic wave, demonstrating various exotic optical phenomena and novel functionalities for a wide variety of applications such as wave-front engineering, enhanced light-matter interaction at nanoscale, and chemica l and biological sensing, to name a few. In this talk, the focus will be first placed upon my recent work on few-laye r metasurfaces for manipulating the terahertz (THz) wave to realize linear-to-circular polarization conversion, optic al antireflection, narrowband filtering, and beam focusing, with unprecedentedly high efficiencies promising for pr actical applications where compact, high-performance THz photonic components and devices are desired. Then, I will switch gears to talk about my work on high-temperature nanophotonics, in which refractory metasurfaces for s olar thermophotovoltaics (STPV) with desirable tailored absorptance and emittance are experimentally demonstrat ed, featuring thermal stability up to at least 1200 °C and a projected STPV efficiency of 18% when a fully integrate d absorber/emitter refractory metasurface intermediate structure is employed. |