Search

This work focuses on developing a solution-based ultra-thin polarizer for liquid crystal displays, utilizing dichroic azo dye AD1 as the key material. The produced AD1 polarizer exhibits excellent optical performance with a dichroic ratio of over 95. The film thickness is less than 200nm. Furthermore, a TN LCD with an incell polarizer is demonstrated. This technology shows excellent prospects for developing high-performance, coatable polarizers with scalability and lower-cost manufacturing potential. © 2023, John Wiley and Sons Inc. All rights reserved.

An approach to developing a thin-film polarizer with high polarization efficiency in liquid crystal cells is presented. The in- cell polarizer facilitates the realization of novel color-conversion liquid crystal displays, where advanced quantum color-converters are used as photoluminescent color filter arrays. We experimentally demonstrated using azo-dye-based embedded polarizers for color-conversion liquid crystal displays for the first time. We systematically designed the device structure and fabrication process. The display is color parallax free and can be driven at regular conditions with good contrast. © 2023, John Wiley and Sons Inc. All rights reserved.

This work demonstrates a high-performance in-cell polarizer adopting photo-aligned azobenzene dyes. On the strength of the multilayered design, a simple fabrication process has been developed to assemble an in-cell polarizer. We have achieved a broadband dichroic ratio after the long-term stability test. Meanwhile, the cell with the proposed in-cell polarizer can be driven regularly without a voltage boost, which renders excellent practicability in liquid crystal display technologies. The structure, fabrication process, and properties of the in-cell polarizer in TN-LCD are thoroughly discussed. © 2023, John Wiley and Sons Inc. All rights reserved.

Ultrathin (<200nm) azo dye polarizing film with a high dichroic ratio (over 150) is developed by photo-alignment methods. Polarizing film prepared by solution-based process (post-photoalignment) and evaporation (in-situ photo-alignment) with a family of azo dye materials with slightly different molecular structures is explored. We study the photostability of these azo-dye films against polarized light. Methods and factors of getting high dichroic ratio and high photostability polarizing films are discussed. © 2023, John Wiley and Sons Inc. All rights reserved.

Xinyi Dai, Shu Tang Faculty of Humanities and Social Sciences, Jinling Institute of Technology, Nanjing, 210038, People’s Republic of ChinaCorrespondence: Xinyi Dai, Email emma2242020@126.comBackground: Research on the restorative environment has long focused on the natural environment, while the research on the humanistic social environment is still in its infancy. In particular, there has been no special research on the restoration of festival environments.Methods: Based on attention restoration theory (ART), Rites of Passage, and social time, a theoretical model of the restorativeness of folk festival environments was established. Through an empirical study of the Qinhuai Lantern Festival Event, the model was tested by structural equation modeling.Results: Overall, there were two paths, direct and indirect, for the positive prediction of restoration by being away and compatibility; fascination direct positive predict restoration, and extent could indirectly positive predict restoration through liminal experience; time of visiting played a moderating role in the positive prediction of liminal experience by being away; the direct positive prediction of restoration by extent was significant and moderating during the Lantern Festival and the lantern fair period.Conclusion: The folk festival environment is restorative. Folk festival environment restoration has the internal mechanism of “environment restoration feature perception → liminal experience → restoration”. The restoration of the folk festival environment is moderated by social time.Significance: This is the first time that attention restoration theory (ART) has been applied to the study of a “hard fascination” humanistic social environment, thus yielding empirical evidence for the development of this theory. The results suggest management requirements for the improvement of the indication system of festival tourism destinations and the promotion of rest and leisure facilities, and management tip

Most existing deep-learning-based single image dynamic scene blind deblurring (SIDSBD) methods usually design deep networks to directly remove the spatially-variant motion blurs from one inputted motion blurred image, without blur kernels estimation. In this paper, inspired by the Projective Motion Path Blur (PMPB) model and deformable convolution, we propose a novel constrained deformable convolutional network (CDCN) for efficient single image dynamic scene blind deblurring, which simultaneously achieves accurate spatially-variant motion blur kernels estimation and the high-quality image restoration from only one observed motion blurred image. In our proposed CDCN, we first construct a novel multi-scale multi-level multi-input multi-output (MSML-MIMO) encoder-decoder architecture for more powerful features extraction ability. Second, different from the DLVBD methods that use multiple consecutive frames, a novel constrained deformable convolution reblurring (CDCR) strategy is proposed, in which the deformable convolution is first applied to blurred features of the inputted single motion blurred image for learning the sampling points of motion blur kernel of each pixel, which is similar to the estimation of the motion density function of the camera shake in the PMPB model, and then a novel PMPB-based reblurring loss function is proposed to constrain the learned sampling points convergence, which can make the learned sampling points match with the relative motion trajectory of each pixel better and promote the accuracy of the spatially-variant motion blur kernels estimation., Comment: 13 pages,8 figures

Powdery mildew is a significant threat to mungbean (Vigna radiata) and black gram (V. mungo) production across Australia and overseas. Despite being present in Australia for at least six decades, and being easily recognized in the field, the precise identification of the pathogens causing this disease has remained unclear. Our goal was to identify the powdery mildew species infecting mungbean, black gram, and wild mungbean (V. radiata ssp. sublobata) in Australia. The internal transcribed spacer (ITS) and large subunit (LSU) sequences of the ribosomal DNA (rDNA) and/or morphology of 57 Australian specimens were examined. Mungbean and black gram were infected by two species: Podosphaera xanthii and a newly recognised taxon, Erysiphe vignae sp. nov.. Wild mungbean was infected only with P. xanthii. Mungbean and black gram powdery mildew ITS sequences from China, India and Taiwan revealed the presence of only P. xanthii on these crops despite controversial reports of an Erysiphe species on both crops in India. Sequence analyses indicated that the closest relative of E. vignae is E. diffusa, which infects soybean (Glycine max) and other plants. Erysiphe vignae did not infect soybean in cross-inoculation tests. In turn, E. diffusa from soybean infected black gram and provoked hypersensitive response in mungbean. The recognition of a second species, E. vignae, as another causal agent of mungbean and black gram powdery mildew in Australia, may have implications for existing fungicide control measures and breeding.

info:eu-repo/semantics/published

Self-powered smart windows are desirable with the expectations of their energy-saving, weather-independent, user-controllable, and miniature performance. Recently developed solar- or thermal-powered smart windows largely depend on the weather conditions and have an extremely slow response, and only a certain portion of the saved energy can be utilized by the external circuit for mode conversion. In this work, a self-powered normally transparent smart window was developed by the conjunction of a rotary freestanding sliding triboelectric nanogenerator (RFS-TENG) and a polymer network liquid crystal (PNLC) cell. To fabricate the PNLC cell, the alignment layer with randomly distributed microdomains was constructed to encapsulate a mixture of LC polymers and nematic LCs. The opacity of the smart window exposed to an alternating electric field was considerably improved owing to the embedded microdomains and a dense web of LC polymers. The ultrahigh haziness greatly alleviates the charge density required for the LC actuation and thus enables the driving by the TENG where the charge amount is usually limited. The RFS-TENG was elaborately designed with six periodic bent triboelectric films and Ag electrodes, which presented an ultralow friction wear and met the frequency requirement to achieve the steady opacity. By harvesting the mechanical energies from ambient environments, the tribo-induced smart window can benefit a wide variety of fields, such as self-powered sunroofs, wind-driven smart farming systems etc. Copyright © 2020 American Chemical Society.

In this article, we present a high performance smart window via micro‐domains manipulation on the alignment surface, which dramatically enhances the power‐on haze by 48%. Large‐scale window with ultra‐hazy state switching in less than 3.5 ms is demonstrated.

Photoalignment is one of the best candidates of the proven market for multi domain display. It allows nearly free pattern to the liquid crystal alignment direction compared to the conventional rubbed polyimide. Most of the available photoalignment materials require polarized deep UV irradiation with a finite dosage. With the consideration of the current limitation with such a small working window, a vertical photoalignment surface by non‐polarized LED light irradiation with large wavelength is proposed and demonstrated. The alignment direction of proposed surface is generated by the inclined non‐polarized light. The measurement results show the alignment properties of this proposed alignment surface are comparable to conventional polyimide. It has stable and uniform pretilt angle, high polar anchoring energy and fast response time. As a result, the proposed alignment layer is robust and especially suitable for large‐area liquid crystal displays which require high performance with stable pretilt angles and multi‐domain purposes.

We propose here a novel multi-layered waveguide liquid crystal (LC) smart window with full color rendering based on a polymer-network liquid crystal system. The inserted position of three-primary-color LED light bars is specially designed, which is parallel to the LC alignment to obtain a higher difference between transparent and scattering states. The optimal matching of polymer-network LC system is experimentally achieved by comparing several groups of LC and reactive mesogen materials. The prepared smart window is measured and analyzed in detail including optical/chromatic test, morphology characterization, and actual application effect. The proposed architecture opens up new prospects of flexible color switchable ability and synchronized full-color display for smart windows without limitations of slow LC response time and complicated field sequential driving scheme.

The Polymer Network Liquid Crystal (PNLC) cell we fabricated is operating in a reverse mode of voltage‐off transparent state. It is found that when we apply voltage to the PNLC cells, the transmitted light color changed gradually and finally became a bit blue. This effect is not found in Polymer Dispersed LC (PDLC) window. The wavelength dependent transmittance voltage curves are reported and we will try to explain this effect by applying the anomalous diffraction theory.

Photoalignment is evaluated by the proven market for patterned alignment display. The performance of photoalignment is demonstrated to be equivalent to rubbed alignment. It allows nearly free pattern to the liquid crystal alignment direction compared to the conventional rubbed polyimide. Most of the available photoalignment materials require polarized deep UV irradiation with a finite dosage. With the consideration of the current limitation with such a small working window, a vertical photoalignment surface by non-polarized blue LED light irradiation is proposed and demonstrated. The alignment direction of proposed surface is generated by the inclined non-polarized light. The measurement results show the alignment properties of this proposed alignment surface are comparable to conventional polyimide. It has good stability and performance in terms of uniform pretilt angle, high polar anchoring energy and fast response time.

The Polymer Network Liquid Crystal (PNLC) cell we fabricated is operating in a reverse mode of voltage‐off transparent state. It is found that when we apply voltage to the PNLC cells, the transmitted light color changed gradually and finally became a bit blue. This effect is not found in Polymer Dispersed LC (PDLC) window. The wavelength dependent transmittance voltage curves are reported and we will try to explain this effect by applying the anomalous diffraction theory.

Photoalignment is one of the best candidates of the proven market for multi domain display. It allows nearly free pattern to the liquid crystal alignment direction compared to the conventional rubbed polyimide. Most of the available photoalignment materials require polarized deep UV irradiation with a finite dosage. With the consideration of the current limitation with such a small working window, a vertical photoalignment surface by non‐polarized LED light irradiation with large wavelength is proposed and demonstrated. The alignment direction of proposed surface is generated by the inclined non‐polarized light. The measurement results show the alignment properties of this proposed alignment surface are comparable to conventional polyimide. It has stable and uniform pretilt angle, high polar anchoring energy and fast response time. As a result, the proposed alignment layer is robust and especially suitable for large‐area liquid crystal displays which require high performance with stable pretilt angles and multi‐domain purposes.

In this article, we present a high performance smart window via micro‐domains manipulation on the alignment surface, which dramatically enhances the power‐on haze by 48%. Large‐scale window with ultra‐hazy state switching in less than 3.5 ms is demonstrated.

Photoalignment is evaluated by the proven market for patterned alignment display. The performance of photoalignment is demonstrated to be equivalent to rubbed alignment. It allows nearly free pattern to the liquid crystal alignment direction compared to the conventional rubbed polyimide. Most of the available photoalignment materials require polarized deep UV irradiation with a finite dosage. With the consideration of the current limitation with such a small working window, a vertical photoalignment surface by non-polarized blue LED light irradiation is proposed and demonstrated. The alignment direction of proposed surface is generated by the inclined non-polarized light. The measurement results show the alignment properties of this proposed alignment surface are comparable to conventional polyimide. It has good stability and performance in terms of uniform pretilt angle, high polar anchoring energy and fast response time.

A front polarizer-free optically rewritable (ORW) liquid crystal displays (LCDs) has been made via a hybrid alignment configuration with dye-doped LCs. The hybrid structure consists of one optically active planar and one optically passive homeotropic alignment layer. The rewritability of the device is achieved by photo- reorienting the azo dye molecules in the active planar alignment layer. The dye doped in LCs function as a polarizer by following the LCs alignment via a guest-host effect so that the front polarizer can be eliminated. This makes the device more compact and easier to operate for image erasing and rewriting. The image rewriting time only requires ~9.0s, which is determined by the exposure energy and LC parameters. The hybrid-mode dye-doped optically rewritable (DDORW) LCD devices could find applications in E-paper, transparent display and various photonics devices.

Smart windows are attractive because of their numerous advantages such as elegance in construction design and energy conservation. Smart windows with variable transmission are especially desirable for obvious reasons. The simplest way to make a variable transmission smart window is to use two patterned polarizers, and control the transmission by changing the relative position of the two polarizers. We have demonstrated a high-dichroic-ratio polarizer by photoalignment and proposed a simple one-step photo-copy method to realize a continuous axis varying polarizer. The patterned polarizer shows high optical performance, and its thickness is as thin as 100 nm, which is favorable in practical window applications.

The ability to continuously alter the light transmittance through a window is significant for many optoelectronic devices. However, such versatility usually comes with additional unwanted power consumption. Here, we demonstrate transmittance-Tunable glass that operates without electrical power. The key element to the device is an axis-varying polarizer, which combines a photoalignment technique with dichroic dye self-Assembly mechanism. By linear translation of one patterned polarizer with respect to the other, different transmittance states can be achieved. Large-scale uniformity and relatively wide viewing angles (±60°) are also demonstrated. Furthermore, low-Temperature treatment (i.e., T < 80 °C) during fabrication demonstrates the device's potential to be made on the plastic substrate. The polarizer with patterned absorption axis can also be used as other optical components such as light amplitude shaping device. © 1989-2012 IEEE.

We employed the technique of photoalignment to fabricate polarizers using dichroic dyes and liquid crystal polymers. By varying the polarization direction of the UV/blue light, polarizers with spatially varying absorption axis were made. Such polarizers have many applications. As an example, we showed how mechanical translation of two such polarizers can be used as a variable transmission smart window, in which no electric power is needed. In this work, a 5cm x 5cm window device was made and demonstrated with very good bright and dark states.

Smart windows are attractive because of their numerous advantages such as elegance in construction design and energy conservation. Smart windows with variable transmission are especially desirable for obvious reasons. The simplest way to make a variable transmission smart window is to use two patterned polarizers, and control the transmission by changing the relative position of the two polarizers. We have demonstrated a high-dichroic-ratio polarizer by photoalignment and proposed a simple one-step photo-copy method to realize a continuous axis varying polarizer. The patterned polarizer shows high optical performance, and its thickness is as thin as 100 nm, which is favorable in practical window applications.

A front polarizer-free optically rewritable (ORW) liquid crystal displays (LCDs) has been made via a hybrid alignment configuration with dye-doped LCs. The hybrid structure consists of one optically active planar and one optically passive homeotropic alignment layer. The rewritability of the device is achieved by photo- reorienting the azo dye molecules in the active planar alignment layer. The dye doped in LCs function as a polarizer by following the LCs alignment via a guest-host effect so that the front polarizer can be eliminated. This makes the device more compact and easier to operate for image erasing and rewriting. The image rewriting time only requires ~9.0s, which is determined by the exposure energy and LC parameters. The hybrid-mode dye-doped optically rewritable (DDORW) LCD devices could find applications in E-paper, transparent display and various photonics devices.

We employed the technique of photoalignment to fabricate polarizers using dichroic dyes and liquid crystal polymers. By varying the polarization direction of the UV/blue light, polarizers with spatially varying absorption axis were made. Such polarizers have many applications. As an example, we showed how mechanical translation of two such polarizers can be used as a variable transmission smart window, in which no electric power is needed. In this work, a 5cm x 5cm window device was made and demonstrated with very good bright and dark states.

The ability to continuously alter the light transmittance through a window is significant for many optoelectronic devices. However, such versatility usually comes with additional unwanted power consumption. Here, we demonstrate transmittance-Tunable glass that operates without electrical power. The key element to the device is an axis-varying polarizer, which combines a photoalignment technique with dichroic dye self-Assembly mechanism. By linear translation of one patterned polarizer with respect to the other, different transmittance states can be achieved. Large-scale uniformity and relatively wide viewing angles (±60°) are also demonstrated. Furthermore, low-Temperature treatment (i.e., T < 80 °C) during fabrication demonstrates the device's potential to be made on the plastic substrate. The polarizer with patterned absorption axis can also be used as other optical components such as light amplitude shaping device. © 1989-2012 IEEE.

In this paper, a TFT based polarization-controllable light-printer for optically rewritable (ORW) liquid crystal displays (LCDs) is proposed. Experimental results with gray scale images are also presented. The light-printer consists o f a vertically aligned nematic (VAN) mono-color TFT LCD as a polarization controlling unit. 420nm LED light source with Fresnel lens forms the projection unit. With this two-dimensional controlling unit, this light-printer can transfer content to a large-area ORW LCD panel easily.

In this paper, a TFT based polarization-controllable light-printer for optically rewritable (ORW) liquid crystal displays (LCDs) is proposed. Experimental results with gray scale images are also presented. The light-printer consists o f a vertically aligned nematic (VAN) mono-color TFT LCD as a polarization controlling unit. 420nm LED light source with Fresnel lens forms the projection unit. With this two-dimensional controlling unit, this light-printer can transfer content to a large-area ORW LCD panel easily.

The genetic bases of demographic changes and artificial selection underlying domestication are of great interest in evolutionary biology. Here we perform whole-genome sequencing of multiple grey wolves, Chinese indigenous dogs and dogs of diverse breeds. Demographic analysis show that the split between wolves and Chinese indigenous dogs occurred 32,000 years ago and that the subsequent bottlenecks were mild. Therefore, dogs may have been under human selection over a much longer time than previously concluded, based on molecular data, perhaps by initially scavenging with humans. Population genetic analysis identifies a list of genes under positive selection during domestication, which overlaps extensively with the corresponding list of positively selected genes in humans. Parallel evolution is most apparent in genes for digestion and metabolism, neurological process and cancer. Our study, for the first time, draws together humans and dogs in their recent genomic evolution., QC 20130805

The concept of equivalent characteristic parameters of a liquid crystal (LC) cell is introduced together with the characteristic circle and the characteristic ellipse. They are all related to the twist angle and retardation of the LC cell. Such equivalent characteristic parameters can provide a framework for analyzing LC modes, as well as providing a means to measure LC cell parameters. A new Stokes parameter method is also introduced to measure these characteristic parameters. Thus the twist angle and retardation of the LC cell can be determined accurately.

Column leaching experiments were carried out to study the effects of simple and complex aqueous solutions of different types of reagent such as collectors, inhibitors and foaming agents on the release of heavy metals from the tailings. The results showed that reagents which inhibit water solubility have the greatest effect. Continuous leaching of the tailings using complex aqueous solutions of the reagents resulted in much higher release of heavy metals than for acidified tailings with simple reagent solutions. Pollution resulting from multiple reagents, including their degradation products, is the main reason for the release of heavy metals from the tailings dam., Column leaching experiments were carried out to study the effects of simple and complex aqueous solutions of different types of reagent such as collectors, inhibitors and foaming agents on the release of heavy metals from the tailings. The results showed that reagents which inhibit water solubility have the greatest effect. Continuous leaching of the tailings using complex aqueous solutions of the reagents resulted in much higher release of heavy metals than for acidified tailings with simple reagent solutions. Pollution resulting from multiple reagents, including their degradation products, is the main reason for the release of heavy metals from the tailings dam.

There is provided a reflective liquid crystal cell formed of a liquid crystal material disposed between first and second substrates. The first substrate is optically transparent and is formed with a coating of optically transparent and electrically conductive material on the side facing the liquid crystal material. The second substrate is formed with a plurality of coatings on the side facing the liquid crystal material. These coatings include in sequence a layer of metallic reflective material, a layer of electrically insulating material, a layer of na optically transparent and conductive material and a liquid crystal alignment layer.

The present invention provides the conditions for new bistable twisted nematic liquid crystal displays, in particular the necessary twist angles, liquid crystal retardation values, input and output polarizer angles, for both transmissive and reflective liquid crystal displays.

Three measuring methods and apparatus for determining the twist angle (φ) and retardation value (dΔn) of any twisted nematic liquid crystal (LC) cell are disclosed. These methods make use of a monochromatic light source such as a laser beam. Twist angle and retardation values (c)an be obtained by data fitting using data obtained by adjusting only the polarizes and the LC cell orientation. No retardation wave-plate is needed.

Cell gap thickness is one of the most important design parameters for liquid crystal displays (LCD). Existing measurement methods only apply to transmittive LC cells. These methods are obviously unsuitable for measuring the cell gaps of reflective LCDs with internal reflectors. This kind of LCD includes single polarizer reflective displays and liquid crystal on silicon displays. The objective of this article is to introduce various reflective methods of LCD cell characterization that are both applicable to transmittive and reflective LCDs. (C) 2002 American Institute of Physics.

This dissertation proposes and demonstrates an innovative technique for ultra-resolution data storage. An original idea that combines two near-field techniques, aperture probes and the solid immersion lens (SIL), is implemented through modeling, fabrication, testing, phase-change recording, and writing condition studies. In the modeling, a theory for illumination and signal detection is presented. The power transmission for different near-field transducers illuminated by a lens is calculated versus NA. In detection, the angular spectrum illustrates advantages of the combination aperture system. In addition, geometrical design considerations are discussed with the modeling. Nearly optimal designs for APSIL and Al aperture + SIL are presented for the illumination wavelength 488 rim. Fabrication techniques are developed for dielectric aperture + SIL, which is called APSIL, and Al aperture + SIL, respectively through modeling geometrical design. Both near-field transducers are tested by edge-scan experiments. Spot size and optical efficiency from the APSIL system are evaluated. APSIL is evaluated for high-density recording on a phase-change medium. Minimum mark size and the modulation transfer function (MTF) are obtained experimentally. Control of writing conditions for an APSIL system are investigated with respect to polarization, axial focus position and transverse beam alignment. Our study shows that the APSIL system achieves much higher optical efficiency than aperture probe systems as well as exhibits better resolution than SIL systems.

We introduce a 4x4 Mueller matrix for describing the polarization states of a liquid crystal cell. Using this Mueller matrix, it is possible to derive conditions whereby a linearly polarized input can be converted to either a perfectly linearly or perfectly circularly polarized output. These are called the perfect polarization conversion (PPC) conditions. These PPC conditions can be used in many different ways. For example, based on these PPC conditions, polarization mode switching schemes can be derived for the analysis of most liquid crystal displays. (C) 2001 American Institute of Physics.

We introduce a 3 × 3 matrix for the study of unitary optical systems. This 3 × 3 matrix is a submatrix of the 4 × Mueller matrix. The elements of this 3 × 3 matrix are real, and thus complex-number calculations can be avoided. The 3 × 3 matrix is useful for illustrating the polarization state of an optical system. One can also use it to derive the conditions for linear and circular polarization output for a general optical system. New characterization methods for unitary optical systems are introduced. It is shown that the trajectory of the Stokes vector on a Poincaré sphere is either a circle or an ellipse as the optical system or input polarizer is rotated. One can use this characteristic circle or ellipse to measure the equivalent optical retardation and rotation of any lossless optical system. © 2001 Optical Society of America.

A powerful method for liquid crystal (LC) cell twist angle and retardation measurement is presented. This method is based on the spectroscopic ellipsometry. By varying the polarizer and analyzer angles only, a transmission spectrum containing null transmission at some particular wavelengths can be obtained. Analytical equations derived bases on a polarization analysis of twisted birefringent layers are then solved to give all the LC cell parameters. In general, the twist angle, twist sense, retardation, and the rubbing direction can all be determined. Measurement results on commercial liquid crystal display panels are presented. (C) 2001 American Institute of Physics.

A new Mueller matrix approach is developed for the design of optical modes for all nematic liquid crystal displays (LCD). In particular, for linearly polarized light going into the LC cell, conditions for linear polarization and circular polarization outputs are obtained. By considering the switching between different polarization modes, new transmittive and reflective bistable twisted nematic (BTN) LCD operating conditions with optimized contrast and brightness are discovered. A passive matrix driven single polarizer reflective BTN display was fabricated with reasonably good measured optical performance and fast selection time. (C) 2000 American Institute of Physics. [S0021-8979(00)00602-2].

We describe the novel technology of thin photo-patterned polarizers for LCDs. The polarizer consists of small regions with different orientations of the absorption axis and/or colors. It can be placed on the interior of the LCD cell substrate. The polarizer material consists of thin (about 0.3-0.7 micrometers) lyotropic dye layers, transferred to the substrates by UV-curing glue or by the "photo-alignment" method. We use photo-chemically stable dyes as the photo-alignment layers for the lyotropic LC and as the thin photo-patterned polarizers

Mueller calculus is employed to find the conditions that govern linear polarization preservation and the linear to circular polarization transformation in a general twisted nematic LC cell. The results are applied to the design of both transmittive and reflective twisted nematic LCDs. New optimized optical modes are reported. This method provides a clear physical interpretation of all LCD modes.

The 2×2 Jones matrix and 4×4 Mueller matrix methods are used as computational tools for LCD quiescent state optical mode design. Matrices of a general twisted nematic (GTN) LC cell and some basic optical components are given. The transmission or reflection of a GTN cell can be calculated easily by using these matrices. A parameter space approach of designing LCDs is described, by which many GTN optical modes are revealed with information on their transmittance/reflectance, dispersion and also cell gap tolerance. The 4×4 Mueller matrix is introduced both as an alternative to the Jones matrix calculation and an efficient tool for investigating GTN cell polarization transformation. A polarization transformation switching scheme is proposed to explain all GTN display operations. New bistable twisted nematic (BTN) modes are invented by considering horizontal switching of linear polarization preservation modes.