In this paper, broadband Spectral Domain Interferometry provides single-shot optical characterization of dispersive thermotropic nematic liquid crystals. The proposed experimental setup enables measuring the chromatic dispersion, the extended Cauchy equation parameters knowing the optical index for one wavelength, and the thermo-optical coefficients to ascribe the dependence of the optical index with the inner temperature. The analysis is applied to the commonly known E 7 mixture and to M L C 2132 , whose chromatic properties are not referenced although the mixture is commercial, demonstrating the latter’s interest for electro-optical or thermo-optical applications of thick nematic liquid crystal cells.