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Planarly aligned cholesteric liquid crystals of short pitch were applied by the in-plane electric field. The reorientation of the director, increasing pitch, and flexoelectricity induce the change of transmission. The main effect in this research is due to the director reorientation along the electric field. The flexoelectricity deters the change in the birefringence induced by the dielectric response. The response was very fast for the effectively thin periodic boundary of the half-pitch of liquid crystal. The contrast ratio was more than 80 for red light and the response time was less than 0.1 ms for the experimental conditions. [ABSTRACT FROM AUTHOR]

We construct quasi four-fold symmetric orientation patterns by irradiating laser light on a photoactive alignment layer. Double irradiations of spatially modulating interference light in orthogonal directions form symmetric patterns consisted of two stably and dominantly aligning liquid crystal (LC) domains. The LC texture continuously changes accompanying the switching, each state is definitely memorized, with changing electric field strength. A large number of quasistable but effectively stable states exist between two equivalently stable states. This will be suitable for next generation displays that will express full gray scale with multistability. [ABSTRACT FROM AUTHOR]

The alignment of liquid crystals is important in the manufacturing of devices. Usually, the alignment layer is prepared using a thin-film coating, thermal processing and processes such as rubbing or photo-alignment. Several trials without processes related to the alignment layer were performed for realizing vertical alignment. The main approaches were to utilize the self-assembly of the alignment agent on the substrate. Here, tiny amount of fumed silica, a kind of nano-particle, was added to nematic liquid crystals. With a low frequency electric field and thermal treatment, the region of vertical alignment was obtained. In addition, the efficiency of alignment was related to the polarity of the electric field. The vertical alignment by the fumed silica was active for negative polarity. This results in an easy and convenient way of obtaining vertical alignment. [ABSTRACT FROM AUTHOR]

K(Nb1− xMn x)O3 (KN1− xM x) ceramics with 0.005 ≤ x ≤ 0.015 were sintered at 1020°C through a normal sintering process without the formation of a liquid phase. They exhibited double polarization versus electric field ( P-E) hysteresis and sprout-shaped strain versus electric field ( S-E) curves owing to the presence of a defect dipole ( PD), which was formed between the acceptor Mn3+ ion and the oxygen vacancy. Moreover, the aging process was not required to develop the PD. The KN1− xM x ceramics exhibited a large strain of ~0.2% at 6.0 kV/mm. For the KN0.985M0.015 ceramic, this large strain was maintained after 104 cycles of an electric field of 6.0 kV/mm. This ceramic also maintained a double hysteresis curve at 200°C. Therefore, the KN0.985M0.015 ceramic has a large electric field-induced strain, along with good thermal and fatigue properties for multilayer piezoelectric actuators. [ABSTRACT FROM AUTHOR]

We investigate the inter-particle interactions of weak homeotropic anchoring when electric field is applied parallel to far-field director in a homogeneous nematic cell. Two particles interact with the dipole–dipole and quadrupole–quadrupole interactions in the cell. A model of far-field solution dependent on the cell gap and the electric field with weak anchoring is considered to explain the experimental results. The effective radiusis introduced to adapt the anchoring strength effect using the radius (R) and a coefficient. The model was experimentally proved with varying electric field and cell gap and it was reasonable for weak electric field. The coefficientwas measured to beandfor the dipole–dipole and quadrupole–quadrupole interactions, respectively, within the experimental range of the weak electric field. The anchoring strength was calculated as ~ [ABSTRACT FROM AUTHOR]

Abstract: The effective rotational viscosity and polar anchoring coefficient of a nematic liquid crystal were determined using electro-optical response by changing the frequency of the electric field in the kilohertz range. Both quantities monotonically decreased with an increase in the frequency and converged to a certain value at several tens of kilohertz. The effective rotational viscosity changes more than the order of magnitude in experimental range. On the other hand, the effective value of anchoring coefficient changes several times. We tried to explain the trends with the effect of an electric field induced by the motion of ionic impurity in liquid crystal. [Copyright &y& Elsevier]

Colloidal particles dispersed in nematic liquid crystals are aligned along the orientation that minimizes the elastic free energy. Through applying an electric field to a nematic colloidal system, the orientation of the director can change. Consequently, colloidal particles realign to minimize the total free energy, which is the sum of the elastic and electric free energies. Herein, we demonstrate that if the preferred rotation directions given by the electric and elastic free energies are different during realignment, the rotation direction of the particle can be controlled by how we apply the electric field. When the strength of the electric field gradually increases, the particles rotate in the same direction as the rotation of the director. However, when a sufficiently high electric field is suddenly applied, the particles rotate in the opposite direction. In this study, we analyzed the effect of free energy on the bidirectional rotation behavior of the particles using a theoretical model. This study provides an effective approach to control the rotational behavior of colloidal particles over a wide-angle range between two orientational local minima. [ABSTRACT FROM AUTHOR]

We propose a tunable multiwavelength-swept laser based on a nematic liquid crystal (NLC) Fabry–Perot (FP) etalon, which is embedded in the resonator of a wavelength-swept laser. We achieve the continuous wavelength tuning of the multiwavelength-swept laser by applying the electric field to the NLC FP etalon. The free spectral range of the fabricated NLC FP etalon is approximately 7.9 nm. When the electric field applied to the NLC FP etalon exceeds the threshold value (Fréedericksz threshold voltage), the output of the multiwavelength-swept laser can be tuned continuously. The tuning range of the multiwavelength-swept laser can be achieved at a value greater than 75 nm, which has a considerably wider tunable range than a conventional multiwavelength laser based on an NLC FP etalon. The slope efficiencies in the spectral and temporal domains for the tunable multiwavelength-swept laser are 22.2 nm/(mV rms ∕ μ m) and 0.17 ms/(mV rms ∕ μ m), respectively in the linear region. Therefore, the developed multiwavelength-swept laser based on the NLC FP etalon can be applied to an electric-field sensor. Because the wavelength measurement and time measurement have a linear relationship, the electric-field sensor can detect a rapid change in the electric-field intensity by measuring the peak change of the pulse in the temporal domain using the NLC FP etalon-based multiwavelength-swept laser. [ABSTRACT FROM AUTHOR]