Ultrashort helix pitch antiferroelectric liquid crystals based on chiral esters of terphenyldicarboxylic acid

Abstract

Antiferroelectric liquid crystals (AFLCs) with a nanoscale helix pitch (<100 nm) were revealed in a composition containing achiral smectic-C biphenylpyrimidines and two non-mesogenic chiral dopants.

Design of polar self-assembling lactic acid derivatives possessing submicrometre helical pitch

“…The electro-optic parameters of the studied compounds are temperature dependent, namely, the spontaneous polarisation and tilt angle, which are extremely important for practical applications [ 5 , 44 ]. However, these parameters can be stabilised by formulation of the multicomponent mixtures which goes beyond the present work.…”

“…By simply applying an electric field, it is possible to reach uniform alignment which remains very stable with time. Their most exciting property, namely the helical pitch length of 120–320 nm, makes the materials from the KL n / m series potentially applicable for the design of advanced functional multicomponent mixtures (like in [ 44 , 47 – 50 57 – 58 ]) aimed for electro-optic and photonic devices based on the deformed helix ferroelectric effect [ 5 , 41 – 44 59 ]. Further studies of similar materials are in progress and will be presented elsewhere.…”

“…Recently, a deformed helix ferroelectric (DHF) effect [ 5 , 41 – 44 ] discovered in smectic liquid crystalline materials became a focus of interest of the scientific community due to its application potential. Generally, this effect is characterised by a tunable, continuous, and hysteresis-free optical phase shift that operates at low voltages.…”

“…Generally, this effect is characterised by a tunable, continuous, and hysteresis-free optical phase shift that operates at low voltages. By using the DHF effect, the possibility for realising specific displays, effective light shutters, voltage sensors (with exceptionally fast response and near-perfect linearity and low-cost), and tuneable telecommunication optical fibres [ 45 – 46 ] is very encouraging [ 5 , 44 ]. However, requirements for materials that perform at the DHF mode are usually very complex, which multicomponent mixtures [ 44 , 47 – 50 ] only can fulfil.…”

Electric field-controlled transformation of the eigenmodes in a twisted-nematic Fabry–Pérot cavity

“…A high-speed defect mode switching in optical cavity with a nematic LC can be realized using a narrow peak schift and a fast part of the molecular orientation 21,22 . The response time of the presented rotation is expected about of milliseconds and can be improved to microseconds for ferro- or antiferroelectric liquid-crystal materials 23 and has a potential for submicrosecond response 24,25 . We anticipate the presented polarization rotation principle operation for other helix materials with faster response in expense of the cavity thickness or absorption.…”