The paper deals with photometric and morphologic analysis of bioluminescent images obtained by registration of light radiated directly from some plant objects. Registration of images obtained from ultra-weak light sources by the single photon counting (SPC) technique is the subject of this work. The radiation is registered by use of a 16-bit charge coupled device (CCD) camera "Night Owl" together with WinLight EG&G Berthold software. Additional application-specific software has been developed in order to deal with objects that are changing during the exposition time. Advantages of the elaborated set of easy configurable tools named FCT for a computer-aided photometric and morphologic analysis of numerous series of quantitatively imperfect chemiluminescent images are described. Instructions are given how to use these tools and exemplified with several algorithms for the transformation of images library. Using the proposed FCT set, automatic photometric and morphologic analysis of the information hidden within series of chemiluminescent images reflecting defensive processes in poinsettia (Euphorbia pulcherrima Willd) leaves affected by a pathogenic fungus Botrytis cinerea is revealed.

In this paper, a concept of an inexpensive PVDF pyroelectric radiation sensor of large aperture is described. The design details of a pyroelectric sensor based on the PVDF polymer are given. The preamplifier and conversion system of pyroelectric sensor signal are presented. Its photoresponse to short radiation pulses was investigated experimentally. Especially, influence of such parameters as frequency of optical pulses, width of pulses and temperature on the photoresponse of a given pyroelectric sensor was considered.

The paper presents a design model of a photometric head of luminance distribution meter. For the construction of this model optical fibers and CCD array were used. Such a photometric head makes it possible to obtain data about the distribution of optical radiation coming from the light sources located in a very large solid angle (even in the whole halfspace) only by a single measurement.

The brightness distribution in vision process is very important. The object being in the center of attention, laying in the middle of field vision should be the most bright. The nearest surroundings of that object should possess lower brightness and the background least of all (average value). According to recommendations the luminance quotients of following areas: background to the nearest surroundings and to the visual field should be 1:3:10. In this work authors present three sections fiber optic head for luminance measurer giving possibilities to calculate luminance distribution in each section of vision field.

Apart from the measurement of illuminance on the plane surface, it is also necessary to measure half-cylindrical illuminance (according to the rules and other recommendations). The luminous flux incident on the photometer's head has to be corrected (according to the definition of the luminous flux). It is possible to do this spatial correction using light fibers having very small numerical aperture (NA). Authors present this kind of construction.

In many cases we have to measure the luminance function in the space. This function we can find in the conventional way -- making a lot of measurements in different directions. For the purpose of automatization of that process, authors offer new construction of fiber optic photometry head for luminance measurement, based on light fiber element which is turning around in half-space and cooperating with the CCD element. All data from detector are analyzed by computer.

There is a large number of elements used for spatial correction of the luxmeter photometric head. However, none of them, as yet, ensures perfect correction. As a result, research work into this type of correction has been playing a crucial role in the measurement of photometric quantities. In this paper an original model of a luxmeter photometric head created on the basis of optical fibers has been presented. This photometric head operates on the principle of measurement of the spatial distribution of luminous flux.

In this study it was shown that when the measurement of luminance distributions are made by means of a CCD array spectrally corrected by a set of absorption filters positioned behind the lens, the measurement accuracy depends, among other factors, on the size of the diaphragm at which the measurements are made. The distributions of the spectral correction error on the surface of the spectrally corrected CCD matrix in relation to the angle of view of the lens and the diaphragm used during the measurements are also presented.

Various light sources are applied for signaling (traffic lights, information boards and advertising boards). Mainly, there are halogen reflectors, light emitting diodes (LED) and standard sources of laser light. Light intensity measurements were performed as emitted from 1mm² of source area. It enables easier evaluation and comparison in terms of best matching of particular light sources to fiber optic technology.

This work is devoted to the analysis of the shape of transmission spectra of stratified systems with a deposited thin adsorbed layer. It is demonstrated, that the transmission spectra are in general determined by coherent light scattering of the molecules in the deposited layer and interference of this scattered light with the incident one. As a result, the shape of the dispersion of both imaginary and real parts of the layer's dielectric function determines the transmission spectrum instead of only the imaginary part as in the case of transmission spectra of adsorbed layers on a transparent bulk substrate. The fact that such spectra can not be constructed from the absorption spectra of the stratified system and the deposited film alone was often the reason for seeking of new interactions in such systems. We demonstrate that this non additive property of the spectra has to be expected for such systems in general also in the absence of such interactions and that the position of the minimal transmission in a normalized spectrum does not correspond to the position of an absorption line. It is shown that the shape of such spectra is described by an asymmetrical line like a Fano line and that the origin of such a shape can be associated with the physics underlying a Fano resonance. A new approach for the determination of the dielectric function of deposited films is proposed on the basis of the presented analysis. It is demonstrated experimentally and theoretically that the deposition of a thin absorbing layer can give rise to an increase in transmission of an initial system. Conditions of such an increase are presented.

Langmuir (L) and Langmuir-Blodgett (LB) films of perylene-like dye and its binary mixtures with 4-octyl-4'-cyanobiphenyl (8CB) and 4-pentyl-4"-cyano-p-terphenyl (5CT) have been investigated. On the basis of the surface pressure-mean molecular area isotherms, the molecular organization on the air-water interface has been determined. The spectroscopic study of the LB films has allowed conclusions to be drawn about the alignment of the molecules on the quartz slides. The absorption and fluorescence spectra of the LB films of the perylene-like dye have revealed the formation of self-aggregates.

The paper presents benefits of optical time-of-flight spectroscopy for highly scattering materials to determine their basic optical properties (i.e. absorption coefficient, scattering coefficient, anisotropy factor and refractive index). The measurement techniques and methods of measured data analysis are presented too. The measurements were conducted for paper samples, technological liquids from paper mills and aqueous milk solutions. Picosecond semiconductor pulse lasers and fast light detectors (a streak camera and an avalanche photodiode working in Geiger mode) were used. It was shown that systems using these detectors and sources could provide measurement results that are very difficult or impossible to obtain by other measurement techniques.

Methods of optical measurements are widely used in biomedical research. Applications of these methods in determining of properties of camptothecins -- S-phase anticancer agents are described in this paper. Under physiological conditions CPT hydrolyses, and converts into inactive carboxylate form. Decrease of active form of CPT occurs especially fast in plasma of human blood. One of camptothecin analogues -- DB-67, exhibits, in contrary to CPT, relatively high stability in human blood. Fluorescence spectroscopy methods were used to determine physical and to predict biological properties of camptothecins, including DB-67. The dynamic light scattering (DLS) methods were applied to control the sizes of liposomes used as DB-67 delivery system.

Fluorescence spectroscopy methods are widely used in biomedical research. The fluorescence spectra of camptothecin (CPT) -- anticancer agent are analyzed in this paper. CPT can exist in two forms: lactone and carboxylate. Only the lactone form is biologically active. Under physiological conditions (pH 7.4) the lactone form hydrolyses and converts into inactive carboxylate form. There are some differences in fluorescence spectra of lactone and carboxylate form of CPT -- the emission spectra of carboxylate form is slightly red-shifted and is characterized by lower intensity. Principal components analysis (PCA) fallowed by factor analysis (FA) enable to detect presence of both forms on the basis of series of time dependent set of spectra, to follow changes in their contributions and to determine these contributions.

Spectral measurements of a laser-produced soft x-ray and EUV source based on a double-stream gas puff target are described. The target was irradiated with a Nd:glass laser producing 1 ns pulses with energy up to 10 J. Production in the wavelength range up to 20 nm (x-ray and EUV emissions) have been measured from xenon, krypton, argon, and nitrogen targets using the transmission grating spectrometer with the back-illuminated CCD. Spectral characteristics of x-ray and EUV emissions are presented.

By IR spectroscopy methods the structural changes of high molecular polymers irradiated by CW CO₂-laser radiation was investigated. Some changes in the structural sensitive regions at 1250 - 950 and 950 - 850 cm^-1 of the IR spectra of the investigated polysaccharides [pullulan (molecular mass of 14500) and microcrystalline cellulose (structural modifications I and II)] were exhibit. These changes indicated that the degree of conformational order of polysaccharide molecules increases under the laser irradiation, while its structural order always decreases as a result of heating by traditional thermal sources.

A fiberoptic Raman spectroscopy system was adapted to remote measurements made in conditions typical for chemical industry. This technique was used to diagnose a process of synthesis of amine-epoxy based hybrid polymers, developed as a new class of adhesive materials for optics. Hybrids, manufactured in sol-gel technology, have a great application potential, because their properties may be formed in wide range. However, to obtain a high quality product, a strict control of the manufacturing process must be ensured. The main goal of research, presented in this paper, was to investigate the course and efficiency of the most important reactions, which takes part during the gelation -- the first step of the sol-gel process. An optical system developed for the real-time monitoring was connected with typical glass reaction vessel and non-invasive measurements were made. The results enabled to find the appropriate conditions for the reaction between amine and epoxy groups. Moreover, time of the hydrolysis of monomers and condensation of inorganic network was measured as well as efficiency of these reactions was proved to be very high.

Results of experimental investigation of speckle created by the reflection of laser beam from ruffled surface of liquid with limited number of statistically independent scatterers are presented. First order intensity statistics are investigated. Dependence of higher order statistical moments on amplitude of ripples is presented. Possible applications are discussed.

An instrument for inspecting polished surfaces was built in the Institute of Applied Optics. The instrument called scateroscope enables measuring the rms roughness and visualization of surface defects and particles of contamination. It is especially useful for assessment high quality glass plates, mirrors and semiconductor wafers. The measured plates can be sticked on polishing wheel and can be tested during the polishing process.

One of many hazards in mining industry is presence of airborne dust on underground boards. Hazards caused by dust generated and spread in mines are of the two types: (1) health risk for miners from airborne dust produced from rocks, coal, soluble minerals (pneumoconiosis, toxicity), (2) danger of explosion of carbon dust. Dust particles produced in mines underground range from 0 to about 400 micrometers, have irregular shapes and prevailingly are strongly light absorbing. It is assumed that the most health-risky are particles between 1 μm and 5 μm in size. They are not visible with naked eyes, so their control and measurement need technical equipment. As a standard in polish mines, gravimetric measurement method is used at present. This method works well in post-event evaluation of total health-risk factor, but is not much useful for instantaneous risk warning. In order to recognize and possibly prevent the dust risk as it appears, other methods have to be used, like optical method. Looking towards this demand, an experimental optical dust sensor is demonstrated. The sensor is based on light scattering effect by dust particles, as usual do devices of this type. Originality of this solution lies in construction details of the sensor. Scattering is a complex function of dust kind, size, shape and concentration. Moreover, operating conditions of such a device are cruel -- humidity, elevated temperature, vibrations, and over-all contact with dust -- are harmful for optics. Thus, to achieve reliable indications of the sensor is really a challenge. This paper describes optical construction attempting to overcome difficulties in obtaining dust concentration sensor intended for mining industry and similar applications. First laboratory and operational tests are also reported.

Elaborated turbidimeter is an instrument designed for the monitoring of water quality using the principle of orthogonal nephelometry.

A laser nephelometer for determination of Mueller matrices of the optical properties of objects transforming radiation has been designed. The nephelometer scheme and operation method are described. There have been derived formulas for matrix elements calculation with operating of the nephelometer designed. The polarization characteristics of the probing radiation in the nephelometer are changed by different setting of the first waveplate retarder, and the polarization analysis of the scattered light is carried out with the use of the Fourier expansion of the signal recorded by a photodetector in the process of rotation of the second retardation waveplate retarder placed in front of an immovable analyzer. The absolute error of the Mueller matrix elements measurement have been determined experimentally.

Systematic errors of the Mueller matrix elements for optical properties of objects caused by a misalignment of initial positions of waveplates principal directions and an analyzer transmission axis are considered. The examination is made for the device, in which the probing radiation polarization properties change at different installations of the first waveplate, and the polarization analysis of a scattered light is carried out using a Fourier series expansion of a signal, which one is produced by a photodetector at a rotation of the second waveplate placed before the fixed analyzer. The estimating equations of these errors arising at a separate misalignment of anisotropic optical elements in illuminating and perceiving radiation channels of the measuring device, and equations on which it is possible to judge about a correctness of these anisotropic elements setting are derived. Combined influence of different inaccuracies of anisotropic element installations is considered by the mathematical simulation method and it is compared to experimentally determined behavior of the Mueller matrix elements measurement systematic errors depending on a misalignment of initial position of the first waveplate principal directions.

By laser reflectometry methods the oxide films characteristics formed on the copper cathode surface in the self-maintained glow discharge in helium at the atmospheric pressure was obtained. During the discharge burning the investigations of the oxide films growth dynamics are carried out.

Directional hemispherical reflectance at 10.6 μm of three modification of carbon-carbon (c/c) composites heated in the air by CW CO₂-laser radiation with irradiances ranged from 90 to 16000 Wcm^-2 was measured. At the incident beam intensity of 90 Wcm^-2 the investigated materials reflectance were found to increase with increasing temperature. When irradiance is more than 200 Wcm^-2 the c/c composites reflectance at 10.6 μm is not only temperature dependent but materials modification, and laser irradiance dependent.

In the paper are shown the analytical problems of ascorbic acid determinations in juice with utilization of the dry test technique. Various types of juices are resulted necessity applications different tests types. The separations of sediments on semipermeable membranes and the separations of dark dye by chromatopgraphy type tests make possible test erading and ascorbic acid determinations.

The possibility of diagnostics of the composition and state of blood in a cuvette with plane-parallel walls by the polarization characteristics of the scattered laser radiation has been revealed. It has been established experimentally that the use of λ = 0,63 μm laser radiation linearly polarized in the plane of incidence under certain conditions of probing and observation makes it possible to minimize the distortion of the parameters of the radiation scattered by the sample in the cuvette by its boundaries. We have found the range of recording angles, which provides the widest interval of changing the degree of polarization characterized by the two first Stokes parameters of the radiation scattered by the blood in the case of changing its state.

The method of IR spectroscopy for a quantitative evaluation of a structure anisotropy of metastable organic polycrystalline films is offered. In the method the division of an inverse problem of complex optical parameters determination into a number of stages with optimization on no more than two unknown parameters is used. It provides a capability of graphic support of optimization process and, as a result, minimization an error and operating correction of a possible ambiguity at each stage of the inverse problem solution. It is shown that for polycrystalline films the degree of crystallites orientation f is determined by ratio of their anisotropy. Its relation to the common used degree of crystallites orientation, which can be introduced properly only in a case of weakly absorbing films, is considered. The described method is used for investigation of optical and structural parameters of anisotropic polycrystalline copper phthalocyanine films of α-form in bands of a weak absorption (nonplanar molecular oscillations and plane skeleton deformation oscillations at about 769 cm^-1 and 754 cm^-1, respectively).

Modeling of the light interaction in magnetic structures represents a problem of optics of anisotropic media based on solution of the Maxwell's equations. Magneto-optic medium is described using permittivity and permeability tensors, however, the permeability tensor is mostly set to its vacuum value for optical frequencies. The permittivity tensor can be expanded into a power series as a function of magnetization components. Linear and quadratic effects of the magnetization are characterized by linear and quadratic magneto-optic tensors, respectively. A complexity of the tensors and a number of the independent tensor components are reduced by including the crystal symmetry and the Onsager's principle. We describe, how the magnetic ordering affects eigenmode polarizations in magneto-optic media. Magneto-optic angles dependence on the magnetization components is discussed in details. Quadratic or second-order terms also affect significantly the magnetization measurement. Particular attention is devoted to magneto-optic effects in cubic crystals. While the optical and linear magneto-optic properties of cubic crystals are independent on the direction of crystal axes, the quadratic effects exhibit strong anisotropy. The theory was completed by an experimental observation of the quadratic effect anisotropy in an epitaxial Fe layer prepared on a MgO substrate. The influence of the magnetization components on the magneto-optic vector magnetometry is discussed for a general magnetization direction.

The application of white-light spectral interferometry with the equalization wavelength determination is extended to propose new techniques for dispersion characterization of optical samples and fibers. First, a configuration of a non-dispersive Michelson interferometer and an optical sample of known thickness is proposed and realized to measure the differential group refractive index dispersion and the group velocity dispersion in the optical sample. Second, a tandem configuration of a non-dispersive Michelson interferometer and a birefringent optical sample of known thickness is proposed to measure the differential group refractive index dispersion in the birefringent optical sample. The latter experimental setup can be effectively modified to measure dispersion in both birefringent and polarization maintaining optical fibers.

The processing of the recorded spectral interferograms including the equalization wavelengths is extended by using autoconvolution method to determine the equalization wavelengths precisely. The equalization wavelength determination is used to estimate the spectral fringe phase function in a two-beam interference experiment with the compensated Michelson interferometer and an optical sample inserted in it under the knowledge of both dispersion in the interferometer and the displacement of the interferometer mirror. The interferometer dispersion is given by the thickness of fused-silica optical sample and its refractive index, which can be evaluated from the Sellmeier dispersion relation. Good agreement between the recorded and theoretical spectral interferograms is confirmed and a new method of determining the optical path differences between beams of the interferometer is proposed.

The calibration system used for measurements of the frequency characteristics of 633 nm He-Ne lasers light is presented in the paper. The system consists of four blocks: the iodine stabilized He-Ne at 633 nm laser frequency standard, optoelectronic unit, microprocessor system and PC compatible computer. The presented system was applied for measurements of the frequency characteristics of the frequency stabilized He-Ne lasers used in the interferometric systems. The analysis of the obtained results is discussed in paper.

Tailored optical fibers (TOF) may have non-standard geometrical shapes and dimensions as well as very complex internal refraction and physical structure. Practice shows, that in numerable cases, the standard measurement methods have to be specially adapted to particular case of a fiber. In some cases, a class of novel methods has to be worked out. In this work we present a number of modified measuring methods that suit the needs of characterization of a few basic kinds of tailored optical fibers such like: nonstandard dimension fibers, noncircular core fibers, complex shape fibers, complex refraction fibers, multicore optical fibers, nonlinear and active fibers. The modified measuring methods of tailored optical fibers include, among others: refractometry, polarimetry reflectometry, scatterometry, nefelometry, measurements of dimensions and shapes. Modifications of classical measuring equipment require usage of optimized light coupling techniques. The characterization and measuring methods of such fibers have to be standardized to enable the designers of the photonic functional systems (such as telemetric, sensory and optical signal processing) to apply them in a reliable and repeatable way.

In the paper a detailed theoretical analysis of the propagation of optical radiation and the energy losses of this radiation in short sections of optical fibers is presented. A laboratory stand for experimental verification of the theoretical results obtained is also described.

The paper presents propagation properties of elliptical fibers with liquid crystal core under the influence of temperature, hydrostatic pressure and external electric field. Initial data on transmission losses of the liquid crystal fiber in the 0.5 - 2.0 μm spectral range is also presented. The scattering loss was found to be around 0,2 dB/cm for elliptical-core (4x18 μm) liquid crystal fibers that is in accordance with other measurements, whereas a significant increase to about 5 dB/cm was observed in liquid crystal capillaries.

We present characteristics of Bragg grating imprinted in highly birefringent side-hole fiber. Using specially developed methods we measured spectral sensitivity of the grating (dλ_B/dX) and the phase sensitivity (dΦ/dX) of the host side-hole fiber to temperature and hydrostatic pressure for each polarization mode. The measurement results for both, the grating and the host fiber, show high difference in responses to pressure and almost identical responses to temperature versus mode polarization. This feature of the Bragg grating imprinted in the side-hole fiber can be potentially used for simultaneous sensing of these two parameters by interrogating wavelength shifts for orthogonally polarized modes. We also present the results of modeling of the phase sensitivities to pressure and temprature for the host side-hole fiber and compare them with experimental values.

This paper presents a new method for analysis of fiber optic GRIN devices. The method based on non-linear ray tracing. Its novelty is introduction of small disturbance in ray path. It is essential when beam focusing in considered. More over that simulates a real condition in the face of focusing collimator also. The two GRIN collimators coupled with single mode fibers in U-bench configuration has been simulated. The result show that presented method agrees with experimental data, so it can be used for future development of small micro-optical devices, for example. MOEMS switches.

Propagation of the light in a waveguide structure may be easily disturbed by the change of a cover. In this study multilayers of 7-octenylotrichlorosilane have been investigated as cover films. The multilayer films were deposited on the planar waveguide by self-assembly, followed by a UV illumination and repeated self-assembly processes. A growth control of the deposited films was performed by the generalized method of an m-line spectroscopy. M-line spectroscopy is one of the most sensitive methods of investigations of the cover materials parameters.

In this paper we analyzed the influence of hydrostatic pressure on modal birefringence in photonic crystal holey fibers. We calculated the spectral dependence of modal birefringence B(λ) and its sensitivity to hydrostatic pressure dB(λ)/dp in the holy fiber with birefringence induced by the lack of hexagonal symmetry in the cladding. The contribution of geometrical effect related to deformation of the holey structure as well as the stress-related contribution to the overall pressure sensitivity were analyzed separately. Our results show that both factors decrease modal birefringence, which results in negative sign of pressure sensitivity. Furthermore, we show that the pressure sensitivity of the analyzed structure is of the same order as sensitivities of the commercially available highly birefringent fibers with stress applying elements like Panda or Bow-Tie.

The configuration of injection laser on the basis of asymmetric quantum well heterostructure with heterogeneous excitation of active region permissive to weaken essentially the threshold current and output power dependence on temperature is suggested. It is shown, that decreasing of output power with spontaneous recombination rate rising while heating the laser diode can be compensated by increasing of injection efficiency of carriers into amplifying quantum well at constant pumping current.

We present theoretical and numerical analysis of stability of Fabry-Perot semiconductor laser with external optical feedback on the basis of wave equation. The analytical expressions for stability criterion and modulation part of photon density have been obtained taking into account singing of radiation in external cavity. The bounds of adaptability of equation based on slowly varying amplitude approximation are described.

Application of remote controlled measurement system for the Light Beam Induced Current (LBIC) technique equipped with digital data acquisition and processing system in the diagnostics of semiconductors has been described. Point by point scanning of the selected region by focused light beam enables to create distribution maps shown as the digital images with 256 gray shades and as the color images. On the basis of measurement of amplitude and phase of generated photocurrent it is possible to locate electrically active defects existing inside semiconductor structure. In the paper application of LBIC technique in examinations of silicon polycrystalline solar cells has been outlined.

The p⁺-v-n⁺ detectors applied in selective detection of nuclear radiation have been examined by the Light Beam Induced Current (LBIC) method. The LBIC method enables the comprehensive analysis of photocurrent generated by focused light beam in the microregion in active area of detector. Results of LBIC examinations allowed comparing two kinds of structures. One kind of the structures is those that fulfill requirements regarding parameters of diodes applied in the detection of nuclear radiation. For other kind, dark current exceeds the permissible value. The capacity-voltage characteristics have been presented too.

In this paper we present the results of a study of the effect of high-temperature stress annealing in nitrogen on the index of refraction of SiO₂ layers in MOS (metal/oxide/semiconductor) devices. The dependence of mechanical stress in the Si-SiO₂ system on the annealing conditions has been experimentally characterized. Subsequently, we have correlated such properties with the dependence of the index of refraction on processing conditions and oxide thickness.

We have analyzed the basic examples of cases of completely transmitted light. The text presents a theory of light transmission through material media. This theory is universal for all electromagnetic ranges. The Law of Light Transmittance is proposed. Moreover, the Ewald-Oseen extinction theorem corresponds to the Law of Light Transmittance, which is shown.

The subject of this paper is concerned with analysis of bio-optical signals to be acquired from a tissue slab exposed to selective transillumination. Changes in biophysical and optical parameters of the layered living tissue composition are considered to predict output results of occurring interactions. Especially, influence of changes in optical pathway on efficiency of light transmission through tissues is considered. Series of computer-aided simulation for a representative tissue set have been performed. On the background of data reported in the literature, the authors of this paper describe results collected by them during comparative analytical as well as experimental studies. Taking into account the 3-D approach to the object modeling, it was assumed that dimensions of the smallest component in the object structure are 10 μm x 10 μm x 10 μm. All layers were divided into such elementary cubes. During more than 100,000 simulations in a given direction, the effects of increase in the optical pathway were studied. Exemplary results of calculations for the transilluminated tissue slab are presented, at red light to be acting. The results are presented graphically, where specific changes in the transmittance intensity are given against the thickness of a given layer, which should be treated either optically thin or thick.

Optical imaging of objects inside high scattering medium by use of light instead of X-rays is called optical tomography. There are several types of optical tomography methods. One of them is direct transillumination with laser light in order to collect shadow images as a starting point for tomography procedure leading to three-dimensional object imaging. In this paper we present a modification of a direct transillumination optical tomography method with neural processing to measure a position of the object placed inside water solution of Intralipid, i.e. inside liquid, which simulates optical properties of a living tissue. As a light source a laser diode emitting red light beam (λ ≈ 670 nm) is used. Detection system of transillumination images is based on scanning of the optical field by photodiode. Scattered field measurements for opposite directions of object illumination, are processed by the neural net. In this approach all the time-consuming computations are conducted while training the artificial neural network. Results of object position measurement obtained in works leading to the paper show that neural processing is helpful in better accuracy of the object positioning, than direct image processing.

The essential properties of polymer-dispersed liquid crystals are described. The main attention is paid to the influence of system morphology on electro-optical properties of nematic-containing systems. The thermo-optical properties of dispersed chiral nematics are presented. Electro-optical switching in systems containing ferro- and antiferroelectric liquid crystal phases is shown. The selected applications of the discussed systems are presented, including electrically switchable windows, fast light modulators, sensors, fiber-optic devices and presentations for teaching physics.

In the paper using of vision system to following of position and orientation of mobile robots is presented. Description of the experimental setup is introduced. Two methods of determining mobile robot position and orientation are presented. They are based on two different robot labeling patterns. The first one makes extensive usage of markers, which have individual shape and color. The second method uses four LED diodes placed at the corners of the robot upper surface. The diodes are the active light source. The methods of image processing are also described. Both algorithms of the image processing which extract desired features are also presented. Finally, two applications examples of such measurements information in the control system of the mobile robot or group of mobile robots is presented.

The optical properties of deposition zones formed by an erosion plamsa torch diverging in a vacuum, arising as a result of the action of a high-intensity, unpolarized laser radiation on a copper target are investigated. A very interesting effect has been revealed. On the substrate, approximately at the center of the deposition zone, coaxially to the laser beam, a ring with clearly defined boundaries was detected. The density of the deposited material in this ring was much smaller than in other places. An analysis of the state of the substrate in the ring has shown that this region is formed as a result of the effect of ionic clearing of the surface.

Initial results of study a lateral stress, static and dynamic, on a light propagation in a high birefringent fiber are presented. A permanent birefringence in optical fiber arises due to large thermal stress in the core. Ambient parameters like temperature and hydrostatic pressure influence the stress anisotropy and thus the light propagation. The parameters can be assumed as uniform and the optical response does not depend on the position of the fiber birefringent axes. For a stress (lateral pressure) the optical response of a fiber reveals an azimuth dependence on mutual direction of an exerted pressure and birefringent axes. With dynamic perturbation, even slowly varying, some additional effects like strain can not be avoided. The effective optical response is composed and strongly depends on the direction of stress.