Temperature-Dependent Properties of Terahertz Window Materials

The dielectric properties of common terahertz window materials (quartz and Teflon) at different temperatures were measured by terahertz time-domain spectroscopy (TDS). The applicability of these materials at temperature up to 230 °C was discussed, and the changes of refractive index and absorption coefficient were analyzed combining with Raman spectroscopy. The optical properties of 6H-SiC crystal in the frequency range of 0.2-2 THz were characterized, indicating that it can be used for terahertz optical devices such as lenses. The temperature- dependent measurements show that all the three materials have good temperature stability.