Calculation on frequency and temperature properties of birefringence of nematic liquid crystal 5CB in terahertz band

This letter provides a computational method for predicting birefringence of nematic liquid crystal (LC) in the terahertz band. Using Vuks’ approximation and Haller's approach combination with density functional theory (DFT) and time-dependent density functional theory (TDDFT) method, we calculated the frequency and temperature dependence refractive indices and birefringence of LC 5CB in a frequency range 0.2–1.0 THz. The greater agreement between calculated results and experimental values indicates that this is an applicable method to predict optoelectronic properties of LC materials in THz band. The present work gives a useful guide to screen or design LC molecules for THz applications.