High-temperature infrared properties of sapphire, AlON, fused silica, yttria, and spinel

A vacuum emissometer, utilizing a carbon dioxide laser for high-temperature sample heating, has been designed and built for use with a Fourier Transform spectrometer. A two-color pyrometer technique is used to measure sample surface temperature. Oxides such as sapphire, spinel, yttria, aluminum oxynitride, and fused silica are experimentally characterized in temperature from 600 to 2000 K and in frequency from 500 to 5000 cm−1. A glowing yttria sample has also been characterized over the spectral range of 8500 to 13 500 cm−1. Good agreement with temperature dependent classical oscillator and quantum mechanical multiphonon models for the complex index of refraction is obtained.