Vibrational Nonlinear Response of Liquids Far from Resonance in THz Frequency Range

In this work the dispersion of nonlinear refractive index n2 (vibrational third-order nonlinear response) is estimated for various liquids used in THz photonics – water, ethanol, and isopropanol. To calculate n2 we use the theoretical model that considers known physical, linear and nonlinear optical parameters of liquids. The variation in n2 dispersion in the frequency range with nonresonant electronic contribution for water and ethanol is obtained to be around 15%, which seems to be very important to be considered for THz photonic devices’ design.