Search

We review basic schemes and methods of recording of holographic gratings in liquid crystals, compositions, and devices on their basis. We consider various photochemical and electrooptical mechanisms of this recording, as well as some particular applications of dynamic holography in liquid crystals.

The scheme and operating principle of a new polarizing optical microscope for observing physical fields on object surfaces are described for the first time. New functions of the microscope are achieved because its optical scheme includes a liquid-crystal space-time light modulator, which achieves the contact of the surface under study with a layer of nematic liquid crystal. Examples and prospects of application of this microscope in photonics are considered.

The thin layers of oriented NLC applied on the surface under investigation as a free film can visualize through a polarizing microscope structural inhomogeneities and microrelief defects. On this basis a nondestructive method to study substrates quality has been developed. The results of defect detection on different silicon surfaces are discussed for the first time.

The new optical criterion for objective diagnosis of malignant tumors in human beings and animals tissues is suggested. The molecules of NLC thin layers on sections of malignant tissues have a homeotropic orientation, while on the surface of benign and normal tissues the orientation is almost planar or tilted. Therefore malignant tumors in light microscope with crossed polarizer and analyzer always looks black. The different orientation of NLC molecules is explained by two orders different value of anchoring energy on the surface of malignant and benign tissues. The experiments on contact angles measurement of NLC and H2O droplets on investigated surfaces proved the difference in their surface tension that also confirm authenticity of a new criterion for microscopic malignancies' identification.

The thin layers of homogeneously oriented NLC applied on the surface under investigation as a free film can be used as unusual recording media that permits to visualize the two-dimensional distribution of surface tension with high optical resolution and sensitivity. The changes of surface tension may detect different local defects without applying external electrical fields. On this basis a new non-destructive method to study the quality of different material surfaces has been developed. Here we discuss the new application of NLC technique for histological identification of malignancies.

A thin layer of NLC applied on the surface of a material as a free film can visualize through a polarizing microscope different types of surface defects. We developed a new modification of this LC ...

A new modification of precision safety goggles with improved parameters, compact optical scheme and lower cost, based on a single LC optically addressed spatial light modulator and the field of their applications are discussed.

The thin layer of homogeneously oriented nematic liquid crystal (NLC) applied on an optical polished glass surface as a free film may visualise through a polarising microscope cleaning defects, local physical and chemical modifications of the surface and local relief defects. On this basis a new method to study different types of polished surfaces has been developed. The first results obtained are described.

A new application of the NLC technique in metallography for visualizing the translational and rotational deformation modes in metals after dynamic loading is discussed.

Thin layers of nematic liquid crystals (NLCs) may be used as recording media for visualizing structural and microrelief defects, distribution of low power physical fields and modifications of the surface. NLCs are more sensitive in comparison with cholesteric and smectic LCs having super molecular structures. The detecting properties of NLCs are based on local layers deformation, induced by surface fields and observed in polarizing microscope. The structural surface defects or physical field's distribution are dramatically change the distribution of surface tension. Surface defects recording becomes possible if NLC deformed structure is illuminated in transparent or reflective modes and observed in optical polarizing microscope and appearing image is compared with background structure. In this case one observes not the real defect but the local deformation in NLCs. The theory was developed to find out the real size of defects. The resolution of NLC layer is more than 2000 lines/mm. The fields of NLC application are solid crystals symmetry, minerals, metals, semiconductors, polymers and glasses structure inhomogeneities and optical coatings defects detecting. The efficiency of NLC method in biophotonics is illustrated by objective detecting cancer tissues character and visualizing the interaction traces of grippe viruses with antibodies. NLCs may detect solvent components structure in tea, wine and perfume giving unique information of their structure. It presents diagnostic information alternative to dyes and fluorescence methods. For the first time the structures of some juices and beverages are visualized to illustrate the unique possibilities of NLCs.

The new type of diffraction fractal elements is presented and optical fields properties, obtained from these elements are discussed. Fractal diffraction elements based on well-known fractals, possess exact or statistical selfsimilarity, but have managed amplitude transmittance and phase shift, which are correlated with fractal spatial characteristics. The fractal dimension is not enough for these objects description, and the correlation coefficient between phase/amplitude and spatial characteristic is needed. For this reason the fractal objects were called multifractal structures (MFS). It is shown that the MFS diffraction spectrum possess prevailing power of high frequencies in comparison with spectra of regular two-dimensional or fractal structures with binary transmittance and phase shift. This property could be applied for spatial filtering and transparent objects phase heterogeneities detection. Modeling results for different MFS types are presented and it is shown that MFS application allows detecting the value of initial object distortion with high accuracy. The description of fractal zone plates (FraZP) with variable transmittance and/or phase shift is also presented. The results of Fresnel diffraction modeling from FraZPs with MFS show that the correlation coefficient value has influence on the focal point position.

The imaging process in an ideal optical system with an essentially inhomogeneous source-object, based on a liquid crystal, is discussed.

A new method for visualizing inhomogeneous electric and magnetic field distributions on different mineral surfaces is discussed.

Nematic liquid crystals (NLC) that were traditionally applied for detection of surface inhomogeneities in non-biological objects are proposed as an instrument for the objective microscopic diagnosis of malignancies in oncological practice. The specific alignment of NLCs on different types of tissue is exploited, a previously unknown phenomenon. Malignant tissue decorated with NLC due induces a homeotropic alignment while on benign tissues nematic materials are oriented close to planar mode. The relationship between this phenomenon and the di erent surface tension of malignant and nonmalignant tissues is revealed and the physical nature of these new phenomena is discussed.

It has been shown experimentally that the efficiency of the diffuse component light scattering by liquid crystal elements based on nematics with different structures, possessing the effect of dynamic light scattering, grows with the increase of optic and dielectric anisotropy of the molecules of the liquid crystal material

A technique for experimental investigation of scattered intensities of LC elements showing dynamic light scattering mode has been developed on the basis of methods of the similarity theory conventionally used for description of blackbody spectral chacteristics.

Results of the experimental study of an azimuthal color contrast in the LC displays employing twisted nematic cells with dichroic dyes of different types are discussed.

The goggles based on LC spatial light modulator for protection observers' eyes from blinding objects are discussed.

The education problem in optics and photonics is to draw young generation on the side of light, optical science and technology. The main goal is to prove the slogan that “physics is a small part of optics”: during the thousand years optics formulated the clear worldview for humanity. In fact optics is itself presents multidisciplinary collection of independent scientific arias from one hand and was a generator of new fields of knowledge from the other hand. Optics and photonics are the regions where the fundamental problems of our reality have to be solved. The mentioned functions belonged to optics during the period of civilizations development. This is a basic idea of books serial by S. Stafeev and M. Tomilin “Five Millennium of Optics” including 3 volumes. The first volume devoted to optics prehistory was edit in 2006 in Russian. Its main chapters devoted to relations between Sun and Life, the beginnings of human intelligence, megalithic viewfinders, gnomons and ancient temples orientation, archaic optical materials and elements. It also consist the optical riddles of that period. The volume II is devoted to Greek and Roman antiquity and is in the process of publishing. It consist the chapters on the beginning of optics, mathematical fundaments and applied optics evolution. Volume III would be devoted to Medieval and Renaissance optics history. The materials are used at our university in a course “The Modern Natural Science Conceptions” for students and graduate students. In our paper the possibilities of optics history as effective instrument for education in optics and photonics are discussed.

The optical microscope operation is limited with illumination distribution detecting on the object surface in reflective regime and absorption object parameters detecting in transparent regime. The functions are increased by observation the objects in polarizing light. The inside tension and optical activity in transparent materials becomes visible. Optical polarizing microscopy is powerful tool for investigations in many fields of science and technology. But it is helpless in detecting invisible physical fields’ distribution on the object surface. The combination of optical polarizing microscope with liquid crystal spatial light modulator in contact with objects’ increases its functions.The novelty of microscope consists in LC layer introduction in optical scheme to observe its local deformations in real time. LC applied as recording media has to be in contact with the surface under investigation. In this case LC detects the invisible physical fields on the object’s surface: intermolecular interactions, electrical, magnetic fields, etc. The results were obtained with high optical resolution and sensitivity.The operation with new microscope is very simple. The unique information was received in examination the surfaces of solid crystals, minerals, metals, semiconductors, polymers, glasses, optical coatings. The most valuable information was obtained in biophotonics.The simplicity of new microscopic methods made possible to recruit for serious scientific investigations the students from first to fifth year of education. Students’ participation helps to get rich statistic results and to check their reproducibility. The students also got experience in oral presentations of the results.

The properties of NLC thin layers, applicated upon an optical surface to visualize the defects of the latter, non-detectable by standard means, are studied here in polarized light.

Human influenza viruses are common-acquired respiratory pathogens, influenza rapidly spreads around the world in seasonal epidemics. Methods of influenza viruses detection are based on application of spectroscopic and fluorescence technique. All of them couldn't visualize directly the influenza virus structure modifications, need few days for examination and consist many steps of operation. To avoid the disadvantages the new contact technique with high spatial resolution based on nematic liquid crystals (NLC) application was suggested. The free thin NLC layers applied on the surface under investigation and observed in polarizing microscope are being used in the science and high technologies for structural inhomogeneities detection on the surface of different materials. Simplicity, efficiency and high sensitivity have given an opportunity of universal NLC technique application in crystallography, mineralogy, metallography, thin film technology, medicine and biology. The new field of LC vision application in virus detecting and experimental results are discussed.

The free thin nematic liquid crystal (NLC) layers applied on the surface and observed in polarizing microscope are being used in the science and high technologies for structural inhomogeneities detection on the surface of materials. Simplicity, efficiency and high sensitivity have given an opportunity of NLC application in cancer detection. There were three stages in our investigations. 1. It was discovered that on malignant tissues of animals and human beings NLC have homeotropic orientation while on benign tissues they have planar or tilted orientation. 2. The discovered phenomenon was explained by the surface tension value difference on malignant and benign tumors. 3. The difference in surface tension is based on the particularities of the different parts of the interface layer. The “water” on the boundary with malignant tissues has higher order parameter in comparison with benign tissue. The difference in order parameter was explained by higher concentration of the protein and less concentration of lipids in the “water” on malignant tissues. As the result the anchoring NLC energy on the surface of structural water is higher in comparison with benign tissue. In the first case the NLC have homeotropic orientation in the whole volume of NLC layer while in the second case the surface Fredericks transition is observed.

There is revealed the new phenomenon of the different decoration of malignant and nonmalignant areas in histological tissue sections. The technique of polarized light transmission microscopy and thin (free) layer of nematic liquid crystals (NLC) deposited on the surface of tissue frozen section is cheap, expressive and provide extra information to the pathologist and objective diagnosis of tumors in difficult cases. The phenomenon is connected with different surface tension and contact angles of malignant and benign tissues. The previously unknown physical property of malignant growths may help to understand some intrinsic reasons of the cancer aggressive behavior. A new concept of selective photo treatment on pathology regions that show themselves the most regardless for patient health is suggested.

A new principle of the projection display based on a laser with the conjugate resonator is offered where one of the mirrors is a spatial light modulator (SLM). Intra-cavity reading of the image created on the SLM provides the oscillation of an optical signal as well a generated image with high luminosity and optical resolution.

Liquid crystals (LC) are well known as smart material that changes its properties under the influence of external influence. Usually they used to visualize the distribution of not uniform thermal, electrical, magnetic, acoustic fields or for chemical and radiation detection. In this paper a new unique application of LC for surface tension mapping of solid surfaces is described.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The thin layer of homogeneously oriented nematic liquid crystal (NLC) applied on the optical quality solid crystal surface as a free film may visualize the images of structural defects through a polarizing microscope. On this basis a new non destructive method to study surfaces of different materials has been developed. A new application area of the NLC technique for investigation of structural inhomogeneities in solid crystals is discussed.

A new non-destructive method to study the translational and rotational deformation modes in the metal target subjected to dynamic loading has been developed. This method is based on the nematic liquid crystal technique.

This paper discusses modern principles of constructing displays based on liquid crystals, which provide high-contrast images at large viewing angles. The characteristics of displays based on the twist and supertwist effects and the transverse electric-field effect are considered, along with optical compensator films and multidomain vertically oriented structures. Displays with controllable field-of-view angles are described.

A thin layer of homogeneously oriented nematic liquid crystal (NLC) applied on the optical-quality surface as a free film may visualize, through a polarizing microscope, the images of defects that can not be observed with conventional microscopy: cleaning defects, local physical and chemical surface modifications and microrelief defects. A new vision of polished glass surface defects obtained by the NLC thin-film coating makes it valuable as independent technique for surface quality testing.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The visualization of dynamic strain mechanisms in optical materials by the liquid crystal technique is described.

The goal of the paper is to demonstrate wide fields of new polarizing microscope application based on nematic liquid crystals (LCs) for detecting different solid crystals surface inhomogeneities. Optical polarizing microscope (OPM) based on LCs makes possible to observe the invisible physical fields' distribution on the objects' surfaces. The OPM novelty consists in LC spatial light modulator (SLM) introduction in optical scheme to detect local deformations in real time. LC SLM applied as recording media has to be in direct contact with the surface under investigation. It gives the possibility to detect the invisible physical fields on the surface: intermolecular interactions, electrical, magnetic fields, etc. The theory of LC layer deformations was developed to find the relation between real size of structural defect D and the size of its image D' visualized with NLC layer. OPM method was used for detecting different aspects of surface inhomogeneities for different types of solid crystals. The new results were obtained for twinning boundaries in piezo quartz resonator having industrial application. LC SLM demonstrates non destructive method and better accuracy in comparison with etching, and the simplicity in comparison with x-radiation detecting. LC SLM may be combined with interference, phase-contrast and even near-field microscopes.

The physical bases of the laser effect in liquid crystals are considered. The conditions for the appearance of lasing in various types of liquid crystals are discussed, and low-threshold lasers and optical amplifiers are also described. The features, advantages, and disadvantages of liquid-crystal microlasers are analyzed.

This paper discusses the principles and theoretical foundations of the construction of various types of adaptive lenses based on liquid crystals. It is shown how they have evolved from lenses that operate in polarized light with long focusing times to lenses that operate in unpolarized light with increased aperture and response rate and enhanced image quality. The possibilities of using them in optical systems are discussed.

This paper proposes a new polarization-microscope method of directly identifying influenza viruses and detecting their antigenic properties, based on nematic liquid crystals.

A photometric calculation of the illumination parameters of a projection system and a water dispersion screen has been carried out. The values of the parameters are used to substantiate the contrast difference of the image when there is external spatial irradiance of the screen in a

The information about local changes of H-field detecting domain structures or magnetic inhomogeneities on the surface of magnetic materials is important for science and high technology. It may be obtained with thin layers (≈ 1 μm) of oriented NLCs and polarizing microscope. In the paper we summarize the universal application of LC vision to magnetic domains investigation in mineralogy, metallography and optical technology. In mineralogy the objects of investigation were the sections of rocks with inclusions of ferromagnetic minerals. On the surface of materials applied for storage devices such as (YLa)3Fe5O12 thin films being grown on the substrate of Gd3Ga5O12 the labyrinthical, striped and cylindrical domain structures were observed in the case when the vector of H-field is parallel to optical polarization vector. The domains on the surface of thin amorphous Co based alloy ribbons were investigated using NLC materials with improved value of magnetic anisotropy. The NLC technique results were co...

Conductive polymers are used because of their conductivity, which is associated with the microstructure of the material, determined by its degree of oxidation. To study the conductivity inhomogeneity of polymers, it is proposed to use thin layers of nematic liquid crystals, which reveal the structural inhomogeneity of the surface of the material. © 2004 Optical Society of America

This paper presents information on new technologies for obtaining electronic images in direct-observation and projection-type displays, holographic and stereoscopic systems, and optical methods for protecting securities, presented in the materials of the International Symposium on Electronic Imaging'04 (San Jose, California, USA). © 2004 Optical Society of America

This paper presents information concerning direct-observation liquid-crystal and plasma displays used as big screens for high-definition television and home movies and the prospects for creating three-dimensional television. © 2004 Optical Society of America

This paper describes light attenuators based on electrooptic and nonlinear-optical effects in nematic, nemato-chiral, and ferroelectric liquid-crystal systems intended for the protection of an observer’s eyes from blinding effects. The characteristics of attenuators that operate both over the entire field of view and with local modulation are discussed. © 2004 Optical Society of America

This paper analyzes the properties of "magic" mirrors fabricated by contemporary masters using the technology of ancient China. Interferograms and schlieren patterns obtained from one of the samples confirm that there is a connection between the relief on its back side and the shape of the front reflective surface. © 2004 Optical Society of America

This paper is devoted to the visualization of defects on a silicon surface by means of nematic liquid crystals. Clusters of dislocations not observed in an optical microscope are detected, and this is confirmed independently by an etching method. It is shown that the defect density on the surface of the samples depends on the process by which they were fabricated.

This paper presents a brief review of information-display systems developed in the past ten years and discusses trends in the evolution of cathode-ray tubes and liquid-crystal, cathodoluminescent, LED, and plasma displays. The prospects of using the new display technologies are discussed. The principles of creating bistable and volume displays are analyzed.

This paper discusses the features of the transmission of light by smectic-A liquid crystals (SmALCs). The spectral dependences are obtained for the intensity and the angular distribution of the radiation transmitted through homeotropic and confocal SmALC structures. The optical-loss mechanism in a liquid-crystal medium is discussed. The results of the study can be used to optimize the electrooptic characteristics of color-transmitting LCs of projection displays with a memory function.

This paper presents the results of a measurement of the optical characteristics of LED modules containing as a cylindrical lens a linear raster structure of Fresnel-lens type, intended for large information screens. The causes of the nonreproducibility of the optical characteristics are analyzed.