Discussion on Optical Parameters of Quartz Crystal in the Terahertz Frequency

For crystal quartz, a promising optical material for a high power terahertz waves, there is a lack of substantial reporting in the literature and other sources. For the refractive index, there is a lack of detailed reports on birefringence in THz frequency, while for the absorption coefficient, there is a variation in values in previous literature values. In this study, quartz samples with different geometries and impurity concentrations were analyzed by terahertz time-domain spectroscopy in order to discuss the optical parameters of quartz crystals in detail.