Determination of Pitch in Chiral Smectic C DOBAMBC

Selective reflection, Lagarde, Cano, and light diffraction methods are used for the determination of the pitch in chiral smectic C DOBAMBC {i-amyl-4-[4-decyloxybenzylideneamino]-cinnamate}. All four methods give consistent results. In the selective reflection, the rotation of sample enables the observation of the second peak previously predicted by Berreman, situated at about twice the wavelength of the first peak.