Effect of a Dual Functional Polymer on the Electro-Optical Properties of Blue Phase Liquid Crystals.

The effects of the fluorinated monomer with an ethynyl group on the electro-optical properties of polymer-stabilized blue phase liquid crystals (PSBPLCs) were investigated in different polymer systems. In rigid polymer systems, the Kerr constant can be increased by about 27.6%, while keeping a microsecond response time. In soft polymer systems, hysteresis decreased by about 45.5% and residual birefringence can be reduced from 1.85% to 0.6%. The above phenomena exhibited dual functions of affecting the anchoring energy and the viscosity of the system simultaneously. The results provide a potential value for the ethynyl-containing monomers in PSBPLC systems.

Large aperture liquid crystal lens array using a composited alignment layer.

A liquid crystal (LC) lens array with high light control power and a large aperture using a composited alignment layer is proposed. In our design, the alignment layer is not only used for getting a uniform arrangement of LC molecule, but also for getting a lens-like refractive index distribution in the LC layer when a voltage is applied. Through simple technology processes, a tunable focal length LC lens array with a millimeter scale diameter can be achieved. Furthermore, the maximum phase difference of the proposed LC lens array can achieve 105.38π. So, the proposed LC lens array has a high light control power.

Continuously adjustable period optical grating based on flexoelectric effect of a bent-core nematic liquid crystal in planar cells.

The structures of flexodomains, which are similar to optical gratings and can be controlled by the amplitude of applied voltage and temperature, were verified through polarizing microscopy and light diffraction techniques. The properties of the optical grating induced by a bent-core nematic liquid crystal in planar cells with varied cell gaps and pretilt angles were studied. The period of optical grating decreases with the increase in the amplitude of the applied voltage and pretilt angle. In addition, the period increases with the increase in cell gap and temperature. The period of optical grating has a linear relationship with temperature. The continuously adjustable period has the potential to become an important and extended application of optical grating.

Electro-optical performance of polymer-stabilized sphere phase liquid crystal displays.

Electro-optical properties of polymer-stabilized sphere phase liquid crystal (PS-SPLC) switching devices are analyzed and validated experimentally. The experimental results show the voltage-dependent transmittance curves of PS-SPLC devices. A diffraction approach, called extended anomalous diffraction approach, is proposed to fit the experimental data. Good agreement between experiment and model is obtained. The scattering model provides practical guidance for the improvement of PS-SPLC displays performance and optimization.

Dual-period tunable phase grating based on a single in-plane switching.

We proposed a dual-period phase grating using a polymer-stabilized blue phase liquid crystal (PS-BPLC). High efficiencies of 38% for the short-period phase grating and 30% for the long-period phase grating have been achieved because of the electric-field-induced rectangular-like phase profile of a PS-BPLC, which agrees quite well with the simulation results. The diffraction angle and the diffraction efficiency can be alternatively tuned by a bias voltage and intensity of applied voltage. The diffracted light of each diffraction order is elliptically polarized, and its ellipticity is larger than that induced by using the conventional nematic LCs. Such a device also shows sub-millisecond response time and holds great potential for photonics applications.