Terahertz and Microwave Optical Properties of Single-Crystal Quartz and Vitreous Silica and the Behavior of the Boson Peak

Z-cut single-crystal quartz and vitreous silica (silica glass or fused silica) were evaluated for use as reference materials terahertz microwave measurements of complex permittivity, with confirmed being suitable. Measurements refractive indices absorption coefficients o-ray e-ray in are reported at frequencies between 0.2 6 THz 36 144 GHz, compared data the literature. A previously unreported broad band was seen extraordinary quartz. The Boson peak examined, first time, two negative relationships have been observed: index frequency, height its frequency.