Characterization of temperature-dependent optical properties of materials for metasurfaces in extreme conditions

Knowledge of temperature-dependent optical properties of materials is required for photonics applications in extreme conditions, i.e., at high temperatures. In this talk, we will describe our latest measurements of temperature-dependent optical properties of materials (oxides, nitrides, semiconductors) for the development of metasurfaces for high-temperature applications that include thermal radiators and light sails. We use oscillator-based models to fit ellipsometry data at different temperatures in the wavelength region where a precise measurement can be made, and extrapolate to get broadband temperature-dependent optical properties. We also demonstrate using simulations how metasurface performance is affected by the temperature-dependence of constituent materials.