Rotational Cuvette Measurements for Refractive Index Testing using a THz Vector Network Analyser

This paper describes a new method for measuring the refractive index of liquids using a THz vector network analyser. The method relies on the change of optical path length in a rotating cuvette containing the liquid under test, providing a self-referencing system. The measured phase, as a function of the cuvette angular displacement, is used to calculate the refractive index of hexane, undecane and hexadecane, in the frequency range 0.8-1.05 THz.