Abstract
We report on a new scanning conoscopic method which, by rotating the sample and analyzing the ellipticity of transmitted light, provides an accurate tool to measure the temperature dependence of the two indices
n
e
,
n
o
and of the optical activity for uniaxial liquid crystals. Their determination is useful to give informations about the tilt angle
θ
and the macroscopic helicity in the different phases and then on the structures of the liquid crystal phases. We tested the method with the reference compound (99% S, 1% R)MHPOBC.