We have measured the azimuthal anchoring strength of liquid crystal molecules in contact with poly[4,4'-oxydiphenylen-1,2,3,4-cyclobutanetetracarboxyimide] (CBDA-ODA) films. The measurement was performed for) a 10 nm-thick film exposed to linearly polarized ultraviolet light (LPUVL) of wavelength 〜250 nm at I J/cm^2 as well as for a rubbed film with the same film thickness. Tile infrared (IR) dichroic difference of the phenyl C-C stretching vibration of CBDA-ODA was almost the same for both films. However, the azimuthal anchoring strength for the LPUVI-exposed film was about 5 times smaller than that for the rubbed film. We believe that the small anchoring strength of the LPUVL-exposed film is due to the decrease of the molecular density and/or the decrease of the polyimide chain length that arise from the photo-induced decomposition. In our presentation. we will also report the relation between the IR dichroism of LPUVL-exposed films and the azimuthal anchoring strength.

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We have investigated the surface anisotropy of polyimide films induced by irradiation with linearly polarized ultraviolet light (LPUVL). The surface anisotropy was monitored by measuring the polarized infrared absorption spectra of 〜11 nm-thick films as a function of LPUVL exposure. The measurement was performed for) three kinds of polyimides: poly [4,4'-oxydiphenylene-pyromellitimide] (PMDA-ODA), poly [4,4'-oxydiphenylene-1,2,3,4-butanetetracarboximideI (BDA-ODA), and poly [4,4'-oxydiphenylene-1,2,3,4-cyclobutanetetracarboximide] (CBDA-ODA). We found that the LPUVL exposure dependence of the surface anisotropy is strongly influenced by the molecular structure of polyirnides.

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The evaluation of the surface and flexoelectric polarization has been carried out by a, pyroelectric technique. The temperature increment has been made using a short pulse laser and measured by a, novel time-resolved"optical thermometer" technique monitoring temperature dependent birefringence for a He-Ne laser beam. The temperature dependence of the surface polarization has been measured for both the Planar and homeotropic orientations of a, nematic liuid crystal at a solid substrate.The sign and absolute value of sum of flexoelectric coefficients have also been measured in a, hybrid aligned cell.

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We have applied infrared-visible sum frequency generation optical activity (SFG-OA) technique to study the structures of chiral liquid crystal monolayers. We have successfully obtained SFG-OA signal for chiral MHPOBC and MOBCOB compounds.

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We have designed new types of liquid crystal microemulsions phases in the mixture of the partially fiuorinated liquid crystal molecules and the hydrocarbon liquid crystal molecules for the first time. Microphase separation between the fluorocarbon and hydrocarbon liquid crystal are homogenously embedded in the original liquid crystal order. Frustrated smectic phase is induced by the disorder effect of the microphase separation structure.

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We synthesised a new amphiphilic material which was composed of the liquid crystal part as a hydrophobic and the sugar part as a hydrophilic. We investigated the lyotropic liquid crystalline properties of the trinary mixture, namely BLT sandwich liquid crystal, which was made up this amphiphile, TEG and PAA. As a result, equivalent mixture of amphiphile + TEG and PAA in weight was found to form a novel TGB phase in which the helical axis was propagating along the lamella plane and the nematic-ordered molecules were aligning perpendicular to both the preferred axis and the layer normal.

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We have found the novel TGB phase in liquid crystal microemulsion for the first time. There exist both the lyotropic smectic liquid crystal order and the thermotropic nematic liquid crystal simultaneously in the same space. We call these types of new liquid crystal system as "Bilayer Lyotropic and Thermotropic(BLT) sandwich liquid crystal. Interplay between two liquid crystal orders can produce the long-range elastic interaction between supra-molecular aggregates and stabilizes the nano-structured liquid crystal systems.

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New tilted smectic phases in Langmuir monolayers composed of FLC materials are reported in this paper. We found a mixture of several FLC materials take 2D SmC phase on the water surface at room temperature, showing similar schlieren texture to bulk SmC and nematics. Under compression, unlike the ordinary Langmuir monolayers, the film exhibits first-order monolayer-by-monolayer growth of the film thickness on the water surface, eventually resulting in multilayer-structures instead of collapsing.

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We study the early stages of spinodal decomposition (SD) in binary liquid crystal mixtures by solving linearized time-dependent Landau-Ginzburg equations for concentration (conserved order parameter) and two orientation (nonconserved) order parameters: one for each component. The theory takes into account a cross term between concentration and orientation gradients, which becomes an important factor for phase separation kinetics. We calculate growth rates and structure factors for the order parameters, following thermal quenches from a stable isotropic state into an unstable region. Depending on the quenched temperature and concentration, we find five unstable regions which are characterized by the time evolutions of the structure factors.

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A mean field theory is introduced to describe the phase separations in binary mixtures of a liquid crystal and a nonnematic polymer which means that nematic ordering is forbidden in the constituent pure polymers. The theory takes into account the partial orientational ordering of the polymer chain induced by the liquid crystal solvents. We predicts that a triple point and a new stable nematic phase can be induced by the anisotropic coupling between the polymer and the liquid crystal. The new type of the induced nematic phase are examined for the various molecular weight of the polymer and it's stiffness.

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Novel 1-fluoro- and 1,2-difluoronaphthalene derivatives were designed for active matrix LCD and were prepared through the regioselective fluorination of 6-substituted 2-naphthols. These compounds exhibited high nematic-isotropic transition temperatures with very large dielectric anisotropy and large birefringence.

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Novel 5-fluoro- or 5,7-difluorotetrahydronaphthalene derivatives for active matrix LCD were designed and synthesized through the regioselective hydrogenation of 1-fluoronaphthalenes or the Grignard reaction of 5,7-difluorotetrahydronaphthalen-2-One. These compounds exhibited very large dielectric anisotropy and extremely good co-solubility to host LC.

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We studied the physical properties of three series of new fluorinated liquid crystal components; Decahydronaphthalenes having low Δn and low viscosity with relatively high T_<Nl>, Naphthalenes and Tetrahydronaphthalenes having large Δε and variety range of Δn (0.08-0.21). We have revealed that the fluoro-Cl-substituent for the naphthalene and the tetrahydronaphthalenc ring has effects to increase T_<Nl> and to reduce viscosity with good solubility. Then, we have designed some LC mixtures for AM-LCD having good performance.

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Liquid crystal materials with features of coexistence of high birefringence and low rotational viscosity were developed, by introducing novel class of tolane substance. Those LC mixtures exhibit excellent physical properties, and improve the TN mode display performances significantly. Those LC mixtures had very short switching time at room temperature, 20℃, with thin cell gap TN LCDs. The extremely fast switching characteristics enable TN LC panels to be applicable to field sequential color displays.

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We designed the liquid crystal mixtures for color STN-LCD's with moving pictures using trans-difiuorostilbene compounds (DFS). Especially, they had performances that were rapid response time and good frequency dependence of Vth at low temperature. Further, by using new chiral additives that are phenylpropionic acid derivatives, the properties that were faster response time and the good temperature dependence of Vth were obtained.

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We prepared 5-cyanotroponoids with a forked mesogen at the C'2 position. 2-(3,4-Dialkoxybenzoyloxy)-5-cyanotroponoids showed a monotropic smectic A phase with lower clearing points than those of the corresponding 2-(4-alkoxybenzoyloxy) derivatives, while 2-(3,4,5-trialkoxybenzoyloxy) derivatives showed columnar phases. The corresponding benzenoids, however, were non-mesomorphic. Furthermore, 2-(3,4,5-trialkoxybenzoylamino)-5-cyanotroponoids were able to gelate alcohols and hydrocarbons. Thus, troponoid cores preferred to induce mesomorphic properties. This is due to the presence of the carbonyl group, which played as a lateral dipole group.

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Several benzoic acid derivatives having either perfluoroalkylalkoxy or siloxane substituents are synthesized. These substituents show in general incompatibility with aromatic hard core parts and even normal alkyl groups, which leads to nanophase separated structure, e.g. lamellar like structure. Phase behavior of the neat acids forming dimers through hydrogen bonding and of their 4,4'-dipyridyl complexes are investigated. We found that the 4,4'-dipyridyl complex of 4-(n-heptamethyltrisiloxyl)hexyloxybenzoic acid shows a cubic phase. Furthermore an isotropic-isotropic phase transformation is found in the 4,4'-dipyridyl complex of a branched perfluoroalkylalkoxy group containing benzoic acid derivative.

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New liquid crystalline compounds containing carbazolyl moiety as part of the mesogenic group were synthesized. 2-(9-methylcarbazolyl)-4-cyanobenzoate and 2-(9-metylcarbazolyl)-4-alkanecarboxybenzoate show schlieren texture. 2-(9-methylcarbazolyl)-4-cyanobenzoate has two phase transition temperatures on both heating and cooling processes. By X-ray diffraction measurement of this compound, only one broad weak peak was detected at the mesomorphic temperature in the wide-angle region. Therefore, liquid crystalline phase of the compound was assigned to a nematic phase. 2-(9-Methylcarbazolyl)-4-pentynylcarboxybenzoate shows only one transition peak on heating process and two phase transition peaks on cooling process. By X-ray diffraction measurement, the compound indicates two broad peaks at around 4.5 and 19.0 degree respectively. Liquid crystalline phase of the compound would be assigned to a cybotactic nematic phase based on the shorten molecular length compared with the calculated value and the optical texture.

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The hole transport in mesophases of a smectic liquid crystal, 2-(4'-Octylphenyl)-6-dodecyloxynaphthalene doped impurities intentionally was characterized by time-of-flight technique. Impurities is terthiophene derivatives. And temperature-dependence and dopant-concentration-dependence of hole mobility were investigated particularly.

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Photogeneration and carrier transport in a liquid crystalline photoconductor, 2-(4'-octylphenyl)-6-dodecyloxy-naphthalene (8-PNP-O12) doped with a small amount of C₇₀ was investigated. C₇₀ sensitized its photoconductivity not only in spectrum ranged from 400 nm to 700 nm but also in efficiency. It was found that the photogeneration for holes and electrons took place in the same efficiency when C₇₀ was photoexcited, and that the photogeneration efficiency was increased with the increasing of electric field and doping concentration, which depended on its mesophases. The highest efficiency of 10^-2 was obtained at the C₇₀ concentration of 0.5mol% in the SmB phase. Interestingly, no doping effect on the carrier transport for electrons and holes was observed in that phase. These results indicate a possible application of liquid crystalline photoconductors to high-speed photosensors.

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We have synthesized several liquid crystalline 2-(4'-alkyl phenyl)-6-alkyl naphthalene derivatives and characterized their phase transition behaviors and photoconductive properties. These materials exhibited SmA and SmB phases, which is same as alkoxy analogues, but their liquid crystalline temperature ranges were fairly lower. Electronic transport of positive carriers was observed and their mobility was on the order of 10<-3> cm^2/Vs and 10<-4>cm^2/Vs in SmA and SmB phases, respectively. This indicates that molecular order in smectic layer plays a dominant role on the carrier transport, as far as the core moiety is same.

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We have studied the carrier transport properties in two series of smectic mesophases, from SmA to SmE phases, and from SmC to SmG phases in 2-pahenynaphthalene and terthiophene derivatives by time of flight measurements. With a two-dimensional hoopping transport formalism, we examined the mobility as a function of lhe molecular distance measured by X-ray diffraction and found a good co-relation between them. Thus, the carrier transport characteristics give us another aspect of a probe for elucidating lhe molecular alignment in the smectic layer.

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A large optical nonlinearity in novel photorefractive mesogenic composites was achieved with a low applied defield and a small fringe spacing. The resultant diffraction efficiency from the Bragg gratings was around 40% and tile grating generation time was around 200ms. The demonstration for edge-enhancement of two-dimensional optical images was performed by means of an experimental setup for real-time Fourier transform holography. These edge-enhancement effects were characterized by diffraction efficiencies versus intensity ratio of two writing beams.

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It is well known that the director distribution in a thin nematic liquid crystal (NLC) slab is affected by the substrate surface, as well as by external fields. It is important both of for the basic science and for the technological applications of liquid crystals to understand the director distribution in the NLC slab. We have already reported that a Splay-Bend transition occurs in the NLS slab with a parallel structure by a surface treatment. In this report, the time dependent director distribution is discussed in terms of surface orientation structures, which are the parallel orientation and the anti parallel orientation.

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Molecular dynamics of a fully deuteriated 4-n-pentyl-4'-cyanobiphenyl (5CB-dl_<19>) has been investigated using deuterium nuclear magnetic resonance spectroscopy. Time resolved deuterium NMR spectra, which are originated from C-D bonds on a flexible alkyl chain and rigid biphenyl core of 5CB-d<19>, have been measured to investigate dynamic processes of individual sites of a molecular by an application and removal of the voltage to the cell. It has been clear that each C-D bond sites of 5CB-d<19> rotate simultaneously in a dynamic process in the present measured time region.

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Monolayer structures of a chiral mesogen, (R)-or (S)-[4'-(1-methylheptyloxy)-3'-nitrobiphenyl-4yl] 4-(trans-5-decenyloxy) benzoate, adsorbed on graphite were investigated with molecular dynamics simulations to clarify the mechanism of chiral supermolecular structure formation. We proposed a mechanism model that is based on the coupling between up-down symmetry breaking and the molecular tilt direction symmetry breaking of the monolayer.

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Static ¹⁹F-NMR measurements were performed using a high-resolution solid nuclear magnetic resonance spectrometer. Samples used were 10BIMFn, whose phase sequences show the even-odd behavior with the length of their chiral chains. Dipole coupling constant was larger in the antiferroelectric compounds (n=8,10) than that in ferroelectric ones (n=7,9). From this result, it was found that the molecular conformation around the chiral part in SmC^* is different from that in SmC^*_A.

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The electrooptical properties of achiral bent-core materials have been studied extensively and it was found that the achiral molecules from chiral layer structure in the smectic B2 phase. Little attention, however, has been given to the properties of chiral bent-core mesogens. Herewe report the existence of ferroelectric phases in the chiral material P8OPIMB6 as probed by dielectric and optical second harmonic generation measurements. From optical microscope observation, we conclude that the layer structure of this phase is anticlinic in tilt and ferroelectric in polar order, i.e. the handedness of lhe layer chirality is observed to alternale from layer to layer.

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The local layer structures in the bent-shaped molecules were investigated using X-ray microbeam. In the large circular racemic domains of 10PIMB under an application of ac field, the layer tilt angle δ to the substrate normal is zero, while the layer in the substrate plane is kinked but not bent. This structure does not change irrespective of the distance from the circular domain center. When we turned off the field, the layer apart froin the circle center forms chevron with δ〜10°, and δ decreases as the irradiated position approaches to the center. That is quite similar to the structure of onion. The local layer structure in the uniform domains obtained by the application of an electric field parallel to the substrates were also discussed.

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The structure in the opticaly isotropic (IsoX) phase which appears in the dichiral liquid crystal compond containing fluorines was investigated in the X-ray diffraction measurements. Diffraction pattern depends on the sample and irradiated conditions, and using x-ray microbeam, in a lmmφ capillary glass tube cell, it was found that the IsoX phase is a cubic phase whose symmetry is Im3m. Moreover, an novel optically anisotropic phase in other homologues and the blue-colored texture will be also discussed.

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Anormalous molecular alignment of liquid crystalline conducting polymer which has triple bonds in the main chain, poly(2,5-dialkoxy-p-phcnylenebutadiynyolcnc), has been studied. The anisotropy of electrical conductivity has also been studied using a well-aligled sandwich cell with an interdigitated electrode.

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Reflective full color liquid crystal displays will be used widely in near future because of its low power consumption and clear image not only in a room but also under the sunlight. However, standard evaluation method of the reflective display characteristics has not yet been established. In this research, an accurate measuring method is discussed, the equipment is designed based on it, and finally a standard evaluation method is proposed.

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Reflective color LCDs with high-resolution picture are key devices for highly functional portable information terminals. In this paper, we numerically analyzed the effect of the dispersion of birefringence Δn of the LC and LC-polymer film on the electro-optical properties of new achromatic reflective LCDs using a single-polarizer DTN-LCD and FDTN-LCD with a quarter-wave plate. We found that the LCDs using the typical LC and LC-polymer film exhibit a very high contrast ratio and a high luminous of about 50% by optimum design of the device parameters.

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The reflective color LCD is an important device tbr highly functional portable information terminals. In this paper, we numerically analyzed the electro-optical properties of the previously proposed single polarizer reflective TN-LCD with one LC polymer film and one retardation film. We found that the LCD using the typical LC polymer film with a large dispersion of Δ n exhibits a high contrast ratio and a high luminous reflectance when the retardation of LC polymer film and the driving TN cell are optimized to different values.

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Reflective color LCDs with high resolution are key devices for highly functional portable information terminals. In this paper, we numerically analyzed the electro-optical properties of new achromatic reflective LCDs using a single-polarizer DSTN-LCD and FDSTN-LCD with a quarter-wave plate. We found that the display modes exhibit a high contrast ratio of infinity in theory and a high luminous reflectance of 48%, independent of the duty ratio. In addition, we found that a panel using the display modes exhibits a high contrast ratio by optimizing the driving voltage and/or material parameters independent of the duty ratio.

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We propose a new type in-plane switching mode. By using the continuum theory and 4×4 matrix method, we investigated the optical characteristics of the new mode. From these simulations, it is found that the new mode has an extremely wide viewing angle and its characteristics dose not depend so much on the cell gap.

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Polymer stabilized V-shape FLCDs(PS-V-FLCDs) which are fabricated using an FLC material doped with photo-currable LC monomers(6wt%) and achived the photo-cure in SmC phase under the triangular wave voltage(2kHz, ±10V) was applied. We manufactured a field sequential fullcolor(FS-FC) LCD using PS-V-FLCDs and research on particular TFT driving characteristics. We confirmed that it exhibits V-shape EO response, the ability of gray scale, symmetric voltage holding ratio(VHR) for sign of the source voltage + and -. And it is also independent on the magnitude of source voltage.

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We newly propose a three-dimensional display which does not require any special glasses to observer. In this method, the light from a back-light is controlled in the required direction, and different images are displayed according to each direction. An observer is provided with three-dimensional images by changing the light direction and parallax image on liquid crystal display (LCD) sequentialy. The high resolution can be obtained because the resolution of the displayed images is equal to that of LCD. In this presentation, principle of the display, design condition and property of the light source are described.

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A display by mobile fine particles that can rewrite and has the memory behavior as like an electrical-paper-display, is proposed here. The nematic LC, which mixes fine particles of several decade microns diameter is used for this display. Under the reflection mode, the white display image is caused by the light scattering of fine particles, when the fine particle group has entered the pixel area by an applied electric field, and the black display image is caused by the light absorption material put on the cell, when the group has been out of the pixel area. This report will show the basic elecrtooptical characteristics of this display.

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A smectic A polymer network having permanently, macroscopically uniformly aligned director and layers is successfully synthesized. The mechanical behavior of the S_A-elastomer is highly anisotropic. The modulus in the direction parallel to the layer normal is two orders of magnitude larger than the modulus perpendicular to the layer normal direction. By applying a mechanical stress parallel to the layers no structural changes occur, however we observe a phenomenon based on the in-plane fluidity of smectic layers.

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We prepared poly((4-octyloxy-4'-hexyloxybiphenyl)acrylate)(PA6B8) and poly((4-octyloxy-4'-hexyloxy-biphenyl)methacrylate)(PM6B8). Phase transition and mesogenicity were studied by DSC and X-ray powder diffraction measurements, and polarizing microscope observations. Both of PM6B8 and PA6B8 showed the existence of smectic A phase. However PA6B8 formed crystal and PM6B8 smectic A glass, which was interpreted by hindering the crystallinity due to the presence of the methyl group in PM6B8. We found that mesogenicity and crystallinity of the side-chain liquid-crystalline polymers were influenced by the α-substituent.

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In order to clarify the effect of the sequence linkage between liquid group and flexible alkyl chain on the mesomorphic structure of the low molecular liquid crystal (LC)s, we synthesized the twin and core type low molecular LCs with different sequence of the linkage group. Thermal properties of the twin and core type I Cs were investigated by polarized optical microscopy, different scanning calorimetry and X-ray diffraction measurements. Core type LCs with phenyl-oco- linkage group exhibited nematic and smectic phases depending upon the flexible alkyl chain length. An odd-even effect on the clearing point for the core type LCs were observed, however an odd-even effect on the entropy changes for clearing points was not shown. Twin type LCs with phenyl-oco- linkage group exhibited a nematic phase. Λ remarkable odd-even effect on both phase transition temperatures and entropy changes was displayed for the twin type LCs.

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Hydrocarbon-based hydrophobic polymers on water generally form aggregated particles and do not form spread monolayers. Our recent work showed that hydrophobic polysilanes form all ideal monolayer with the assist of liquid crystal molecule on water. Co-spreading of hydrophobic polysilanes and 4'-pentyl-4-cyanobiphenyl (5CB) provides a hybrid monolayer in which the polymer forms a spread monolayer on top of the 5CB monolayer. This pictue can be verified by the behavior of the surface pressure-area isotherm, Brewster angle microscopy, and atomic force microscopy. The hybrid monolayer can be deposited onto solid substrates having both hydrophilic and hydrophobic surfaces. Onto a hydrophobic substrate surface, only PDHS is deposited and 5CB is expelled from the resulting LB film. This method may open a new clue to the study of ultrathin polymer films.

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Physical gels of nematic liquid crystals can be easily obtained by mixing nematic liquid crystals and low molecular weight gelling agents that form self-assembled network aggregates in solvents. The resultant nematic liquid-crystalline gels show strong light scattering behavior. Electro-optic behavior of the gels in light scattering mode has been examined. Their electro-optic properties are greatly dependent on the combination of components, morphologies of microphase-separated structures, and the tormation processes of liquid-crystalline gel states.

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Polarizing light scattering characteristics of the composites composed of self-assembling low molecular weight gelator and liquid crystal were investigated in order to clarify the molecular aggregation structure of the composites. It became apparent from light scattering measurement that the gelator formed a network structure with a fractal dimension in the composite. A strong relationship between the fractal dimension of the network structure and the electro-optical properties was recognized.

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The reverse-mode light switching, that is, light transmission-light scattering switching upon electric field off-on states, respectively, was investigated for the (liquid crystalline polymer / liquid crystal) composite system in which two kinds of liquid crystalline phases coexisted. However, the generation mechanism of the light scattering in the homogeneous alignment cell upon the application of an electric field has not been clear. In this study, it was found from the polarizing optical microscope observation and light scattering measurements that the light scattering of the homogeneous alignment cell was attributed to the formation of line-shaped domains induced by the application of an electric field. A highly selective light scattering to the linearly polarized incident light was in a strong relation to the existence of line-shaped domains.

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We investigated the effect of several factors, such as monomer structures, LC species, fraction volume of LC, polymerization conditions, on the photo polymerization induced phase separation process(PIPSP) in liquid crystal/polymer composite films. Especially in order to study the effect of the structures monomer on the PIPSP, we synthesized several kind of bifunctional acrylates with different alkyl side chain length. It is clarified that phase-separation process and resulting polymer morphology is remarkably affected by the structure and cohesive energy of monomer as well as the solubility between LC/monomer and curing conditions.

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Spatial distributions of laser-induced refractive index change in liquid crystals were observed by means of a Mach-Zehnder interferometer with high accuracy. The pump laser beam with a Gaussian profile was absorbed in dye-doped liquid crystal and the refractive index was changed due to the photothermal effect. The observed distributions of refractive index change were in good agreement with the Gaussian profile and the value of refractive index change was proportional to the pump beam intensity. Since the generated heat diffuse according to the heat conduction equation, the e^<-2> diameter of refractive index change distribution was slightly larger than that of the pump beam intensity distribution.

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Four kinds of novel polymers, which incorporated both oxadiazole and amine moieties as a charge-transporting emissive unit and an alkyl spacer in the same side chain, were designed and synthesized. Electroluminescent (EL) and liquid-crystalline (LC) properties of the polymers were explored.; poly(2-(4'-methacryloyloxy-n-hexyloxybiphenyl)-5-(3-N-methylcarbazol)-1,3,4-oxadiazole) and poly(2-(4'-methacryloyloxy-n-alkyloxybiphenyl)-5-(4-N,N-dimethylaminophenyl)-1,3,4-oxadiazole) (PMn-OXD-MA) showed LC phases. Furthermore, it was found that the alkyl-spacer length strongly affected the phase structure of PMn-OXD-MA; PM2-OXD-MA did not show an LC phase, but PM6-OXD-MA and PMll-OXD-MA showed a nematic and a smectic A phase, respectively.

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We studied the optical Freedericksz transition (OFT) in an oligothiophene-doped liquid crystal (LC) with linearly polarized and unpolarized laser as the irradiation light. In both cases, OFT occurred at the light intensity of only a few W/cm^2. It was found that the light intensity required for reorientation decreased with an increase in the incident angle for extraordinarily polarized incident light, while a contrary variation tendency was found for ordinarily polarized light. Based on these results and the birefringence of LCs, we evaluated the OFT behavior induced by unpolarized light and proposed a possible way to control the azimuthal angle of the LC alignment.

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