Large extraordinary refractive index in highly birefringent nematic liquid crystals of dinaphthyldiacetylene-based materials

Abstract

The extraordinary and ordinary refractive indices in highly birefringent dinaphthyldiacetylene-based nematic liquid crystals with different alkoxy tails were accurately measured by the multiple-beam interference method. The high birefringence in the nematic liquid crystals was attributed to the high value of the extraordinary refractive index, ne. The value of ne increased from 1.8 to 2.1 as the number of carbon atoms in the alkoxy tail decreased from 12 to 3, whereas the ordinary index, no, remained at approximately 1.6.