Twisted Smectic C Phase: Unique Optical Properties

Abstract

Abstract Single-domain samples of cholesteric liquid crystals and of the recently reported twisted smectic C phase may have identical optical properties for light incident in the direction of the axis of twist. A single Bragg-reflection band exists for either type of liquid crystal in that case. However, with obliquely incident light the twisted smectic C sample would show additional Bragg-reflection bands at optical frequencies intermediate between the bands that would appear in both samples. Examples of computed spectra are given showing the differences that appear as the angle of incidence departs from normal.