Optical reflectivity and ellipsometry studies of the Sm – C*_α phase

Both optical reflectivity and ellipsometry data obtained from freestanding films in the Sm - C*_α phase of one liquid-crystal compound display characteristic oscillations as a function of temperature. A model for the film consisting of surface anticlinic layers and an interior short-pitched azimuthal helix provides an excellent description of our data. Our results show a linear evolution with temperature of the relative interlayer azimuthal angle. The data enable us to place an upper bound on the degree of distortion in the short-pitched helix.