The study of dielectric constant of sapphire based on terahertz time-domain spectroscopy

In this paper, two transmission terahertz time-domain spectral systems (THz-TDS) are developed, their difference is the off-axis parabolic mirror. Based on the transmission THz- TDS, the influence of sample fixture, sapphire thickness and off-axis parabolic mirror on the dielectric constant of sapphire window is studied, and the transmittance of 0.5 mm sapphire window is 66.0%.