Liquid crystals (LCs) represent a very interesting material in the visible range but their properties in the terahertz (THz) range have not been extensively investigated yet. In this paper, we have investigated the THz properties of a set of LCs E7, BL037, and RDP97304 using terahertz time-domain spectroscopy. Refractive indices and absorption coefficients of ordinary and extraordinary axis of LCs are extracted from the measurements. We find that RDP97304 has the largest birefringence and smallest absorption in the THz range compared to E7 and BL037. Thus, RDP97304 is useful for developing efficient and fast THz devices
