This paper presents the results of refractive-index measurements of the extraordinary and ordinary rays in nematic liquid crystals (NLCs) using a refractometric technique in the mid-IR (λ=10.6 µm) and near-IR (λ=1550 nm) regions for NLC E7 and at λ=1550 nm for NLC K15. The optical anisotropy of NLC E7 at 10.6 µm is determined independently by means of the interferometric method in order to compare it with the results obtained by the refractometric technique.
S. Brugioni, R. Meucci, and S. Faetti, "Refractive indices of liquid crystals E7 and K15 in the mid- and near-IR regions," J. Opt. Technol. 73, 315-317 (2006)