Liquid crystal and liquid crystal colloid studied by THz time-domain spectroscopy

THz time-domain spectroscopy is used to measure the frequency dependent complex refractive indices of a pure liquid crystal (LC) and its colloids with SiO2 particles. While the refractive index of the pure LC is found to vary markedly due to distinct orientated domains, the LC colloids provide us with very stable and reproducible spectra, from which the optical functions of the pure LC can be deduced.