Emergence of a novel optically isotropic transient state with low frequency in a blue phase liquid crystal mixture

Abstract

Sung-Tae Shin (2012) Emergence of a novel optically isotropic transient state with low frequency in a blue phase liquid crystal mixture, Liquid Crystals, 39:2, 231-237,The electro-optical hysteresis characteristics in a blue phase liquid crystal system showing multi-domain platelet type body-centred cubic (BP-I) structure at different levels of applied electric field have been investigated. The BP-I state possesses a large degree of hysteresis due to its compact body-centred cubic structure. The hysteresis behaviour is discussed in the context of simulation and theoretical studies reported earlier. When the cell is driven with a low frequency square wave, a novel optically isotropic state with high value of the Kerr constant has been observed. Hysteresis and response time both show relatively lower values in this state with respect to the multi-domain BP-I state.

Effect of the grain size on hysteresis of liquid‐crystalline Blue Phase I

“…Hysteresis is not affected by polymer concentration but depends on the host liquid crystal and chiral dopants. 20 The influence of polymerization on temperature has also been reported by Fan et al 21 In our recent paper, 22 we have demonstrated completely distinct switching routes, determined by the frequency of the electric field applied; however, the characteristic is associated with ionic mobility.…”

Polymer‐stabilized blue phases: promising mesophases for a new generation of liquid crystal displays

“…This aspect needs further studies. On the other hand, many studies report on highly chiral isotropic liquid states with superior electro‐optic properties, which are obtained by photo‐polymerization either in the isotropic liquid phase of a highly chiral LC, in amorphous BP states, or in a metastable state obtained from BP1 through training with low frequency voltages . The physical origin of these states needs further attention and may also expedite further progress.…”

“…On the other hand, many studies report on highly chiral isotropic liquid states with superior electro-optic properties, which are obtained by photo-polymerization either in the isotropic liquid phase of a highly chiral LC, [156,157] in amorphous BP states, [144,158] or in a metastable state obtained from BP1 through training with low frequency voltages. [159] The physical origin of these states needs further attention and may also expedite further progress. The success of polymer-stabilization has also initiated developments of possible non-display applications, such as plastic lasers, [160] tunable photonic crystals, [161] or BP-templated fabrication of photonic nanostructures, [162] polarizationindependent refractive index tuning, [163] switchable Fresnel lenses, [149] photo-induced switching, [164] or optical limiting filters.…”

P‐90: Surface Pinning Effect on Blue‐Phase Liquid Crystal

“…So it is important to reduce the hysteresis and operating voltage in the pure BP sample. In our recent paper we have demonstrated completely distinct switching routes, determined by the frequency of the electric field applied, however, the characteristic is associated with ionic mobility [11].…”