Grating Diffraction in (Anti-)Ferroelectric Liquid Crystal Displays

Current Topics in Smectic Liquid Crystal Research

“…[84,85] In their feature article on orthoconic AFLCs [84] Lagerwall et al reviewed the related earlier work, and found two publications where the optical properties of an anticlinic 458-tilt structure had been considered. In the first one, Taylor et al [98] concluded that the two in-plane refractive indices should be of the same order of magnitude, and in the second, De Meyere et al [99] stated that the in-plane birefringence would be zero. These statements had no impact, however, 5 because both works dealt with other topics (the uni-or biaxiality of the SmC phase and grating diffraction, respectively) and the 458-tilt anticlinic was mentioned only in passing as a hypothetical structure.…”

Editors' Note

“…Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions A recent article in Liquid Crystals by Olsson et al described a new antiferroelectric liquid crystal (AFLC) and its optical and electro-optical properties [1], reporting this AFLC to be the first to exhibit a fieldfree zero-birefringence state due to an effective molecular tilt of 45u. This interpretation was based on a theoretical model of de Meyere et al [2]. In order to enable readers to place reference [1] in its proper context the Editors note that such behaviour had previously been reported in an AFLC by D'Have et al [3,4].…”

A new series of siloxane liquid crystalline dimers exhibiting the antiferroelectric phase

“…While this problem is very difficult to solve for FLCDs, the use of systems with a molecular tilt of 45u in AFLCDs offer a possible solution [29]. It follows from the description of the optical properties of AFLCs given in [29,30] that an AFLC sample aligned in the horizontal AF (HAF) state, with the smectic layer normal and molecules parallel to the confining solid substrates, will exhibit a zero birefringent state, i.e. the field-off state of the sample will be totally black when inserted between crossed polarizers, regardless of the position of the smectic layer normal with respect to the polarizer.…”

“…This comes from misalignment of the liquid crystal that causes a reduction of the displayed image contrast. While this problem is very difficult to solve for FLCDs, the use of systems with a molecular tilt of 45u in AFLCDs offer a possible solution [29]. It follows from the description of the optical properties of AFLCs given in [29,30] that an AFLC sample aligned in the horizontal AF (HAF) state, with the smectic layer normal and molecules parallel to the confining solid substrates, will exhibit a zero birefringent state, i.e.…”