Coefficient of Thermal Expansion of Ultra-stable Materials Measured with $10^{-10}/\mathrm{K}$ Uncertainty

Ultra-stable glasses and ceramics with low coefficient of thermal expansion (CTE) are essential for a wide range of scientific and industrial applications. They are required e.g. in optical atomic clockwork, in astronomy, or in EUV lithography. The CTE of such materials, as Ultra-Low Expansion Glass (ULE®), Zerodur® or cordierite-based ceramics like NEXCERA®, shows a zero-crossing at temperatures close to room temperature. For many applications, the temperature dependence of the CTE around the zero-crossing temperature $T_{0}$ must be known with high accuracy.