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
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 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.
Nowadays the educational problem of teaching optics and photonics is to attract the young generation to the wonderful and magic world of light, optical science, technology and systems. The main issue is to explain that in the course of last several hundred years optics has been representing the most clear world view for humanity. In fact, the optics itself is a multidisciplinary complex of independent scientific directions, and, moreover, it has always been a generator of new fields of knowledge. Besides, optics and photonics are the fields within which the most fundamental problems of today’s reality are to be resolved. It is absolutely necessary to encourage our scholars in getting optics and photonics education as an alternative physical basis to gaining solely computer knowledge. The main obstacle is the poor connection between program of optical education and the real optical researches, disintegration of different branches of the optical science, the demographic situation, some problems with teaching mathematics and physics at schools, and the collision between traditional educational methods and the mentality of the new generation. In Russia the Saint-Petersburg State University of Information Technologies, Mechanics and Optics offers partial solution to these problems: the organization of a real place for interactive optical science in a form of a new museum of optics, intended for education and training, seems to be the most effective way. This was the main reason for establishing such a museum in Saint-Petersburg at the end of 2008.
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
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.
A thin layer of a homogeneously oriented nematic liquid crystal (NLC) can be used as an unusual recording medium for the materials testing in order to visualize the distribution of the weak power physical fields, local modifications and microrelef defects on the surface, and the structural inhomogeneities in the bulk. The initial NLC molecular ordering represents the basis for the external fields visualization. The ordering may be disturbed locally under the influence of the thermal, electric, or magnetic fields, molecular interactions, or electromagnetic irradiation. The recording of these areas becomes possible if the NLC deformed structure is illuminated in the transition or reflection mode, and the interference pattern to appear is studied in the crossed polarizers in comparison with the background structure . The light intensity over NLC layer I(x,y) modulated by the defovried structure is described by the equation I(x,y) = Io sin4[6(x,y)/2], where phase delay o = f(n, nd, ne, no, H); n, nd are the refractive indices of a nondeformed and deformed NLC layers; no, ne are the refractive indices of the NLC layer for the ordinary and extraordinary polarizations, H - the NLC layer thickness.
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 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.
The thin layers of homogeneously oriented nematic liquid crystals (NLC) applied on an optical quality surface as a free film may visualize through a polarizing microscope the images of microrelief or structural defects of the surfaces and also the distribution of mechanical, electric, magnetic fields, etc. The basic theory was developed to describe the image formation process and its relation to physical, chemical, and design film parameters. On this basis a new nondestructive method to study surfaces of different materials has been developed. The application areas of this NLC technique are discussed.