A generalization of the Talbot effect or the self-imaging phenomenon to a tapered gradient-index (GRIN) medium by Fourier Optics is considered. A new interpretation of this effect from the viewpoint of number theory as the output/input relationship between the integer and noninteger difference of position and slope of rays coming from a periodic object is presented. The Talbot effect is demonstrated inside a standar quarter-pitch selfoc microlens.

An approximation to the technological needs of the lighting industry is addressed. Typical photometric tests for different types of luminaries or lighting devices, optical design and simulation processes using specific software, as well as programmes for luminous simulation in projects and reports produced are presented.

Various original applications of dispersive white-light spectral interferometry employing a low-resolution spectrometer and based on the equalization wavelength determinations are reviewed. First, the differential group refractive index dispersion or the chromatic dispersion of a dispersive sample of known thickness is measured determining the equalization wavelength as a function of the displacement of the interferometer mirror. Similarly, the effective thickness of a dispersive sample is determined measuring the mirror displacement as a function of the group refractive index of material. Second, the technique, which needs no phase retrieving procedure to be applied, is used to measure mirror distances and displacements when dispersion in a two-beam interferometer is known. Third, a technique of dispersive spectral interferometry is used for a slightly dispersive interferometer including the effect of thin films. The technique, which needs phase retrieving procedure to be applied in processing spectral interferograms resolved over a wide spectral range, is used to determine the spectral phase of thin films or the positions of the interferometer mirror.

The knowledge of the spectral, power, polarization, and temporal characteristics of laser diodes is of great importance for the development of efficient methods of the light emission control which is required for various applications. In the paper, results of a comprehensive study of the output performance characteristics of quantum-well heterostructure lasers are presented. The main attention is given to asymmetric multiple-quantum-well heterolasers which are possessed of unique functional properties, such as wide-band tuning the emission spectra, multi-wavelength lasing, power switching, and insensitivity to light polarization. The influence of cavity detuning on the nonlinear dynamics of the heterolasers with harmonic modulation of the pump current is analyzed in detail. Four different models of the active medium which allow to simulate different practical situations with respect to the modulation frequency and tuned lasing wavelength are described. Effects of the radiation polarization state on the performance of the heterolasers are studied and operation parameters of the laser diodes required for optoelectronic applications are determined.

In this paper we show different methods of defining and computing of colofulness of the image from digital image processing point of view. All experiments have been carried out on the set of natural color images with different perceptual colorfulness. We have tested the images using following simple colorfulness estimate based on statistical parameters of the pixel cloud along red-green and yellow-blue axes. During image processing the colorfulness of the image can be changed by increasing after color enhancement or by decreasing after image compression. Sometimes the colorfulness of the image should be invariant. We have presented it on examples, which show that the colorfulness can be useful for evaluating the color quantization algorithms beside such traditional performance functions as RMSE and ΔE .

Fast-growing applications of microelements and microsystems, including actuators and sensors, introduce pioneering requirements on their design and testing to ensure product quality and reliability. Optical whole-field experimental techniques are of particular interest because of their speed, noncontact and noncontaminating character. Vibration testing enables providing material properties at the microlevel, design validation, and the information for the manufacturing process optimization. In particular, time average two-beam interference microscopy with automated computer processing of interferograms using the temporal phase shifting (TPS) method is reviewed. The principle of retrieving the zero-order Bessel function (sinusoidal vibrations) by calibrating the contrast variation or intensity modulation of time-average recordings is presented. The influence of main experimental errors is discussed using numerical simulations and comparisons with experimental data. Exemplary results of measurements performed with active micromembranes and AFM cantilevers are presented.

The paper presents benefits of optical time-of-flight spectroscopy for the pulp and paper characterization. A semiconductor pulse laser and a streak camera as the photodetector were utilized in experimental part of research described in this paper. Distribution of the time of flight of photons through various kinds of wood pulp (e.g. pulp after mechanical treatment coming both fi-om tree species giving hard and soft wood and pulp after thermo-mechanical treatment) was measured. The pulp samples used in the measurements had consistency ranging from 0 to 5% of dry mass in the suspension. The influence of additives (kaolin, talc and calcium carbonate) present in the suspension on the time of flight distribution of photons was studied as well. Finally, dependence of the time of flight of photons through various kinds of the paper (i.e. newspaper, copy paper, and tissue) on the thickness of the sample was investigated.

In the prismatic corrections there are described the differences between the nominal and interior prisms, or tilts of the eye to fix straightforward (Augenausgleichbewegung). In the astigmatic corrections, if the prism doesn't lie in the principal sections of the cylinder, the directions of both events are different. In the corrections of the horizontal strabismus there appears the vertical component of the interior prism. The approximated formulae describing these phenomena are presented. The suitable setting can correct the quality of the vision in the important for the patient direction.

Here we analyze simulation of vortex interference with plane colinear wave and experimental verification of that one. The vortex was created with the application of synthethic hologram. Interferometer used for experimental investigation, contain three branches: vortex field, test colinear wave and off axis reference wave. The position of vortex were found in two stages, first with the help of reference wave, characteristic fork pattern was used to localize vortex area, and finally exact position of vortex were found by paraboloid shape matching to intensity distribution . Finally, dependence of vortex position on amplitude and phase of testing wave is presented.

Investigation of liquid thin layers deposited on multimodal waveguide with gradient - index profile has been presented. Properties of the layers have been studied by the generalized m-line spectroscopy method. Deposited on the planar waveguide thin liquid layers have been investigated on the range refractive index 1.0002 - 1.5300. The profile of refractive index of waveguide has not been deformed because of depositing of the thin layer. Depositing of the thin layer on multimodal planar waveguide has caused the change of coupling angle to the waveguide but proportionately to successive modes of the waveguide structure. This study will be helpful to determine, for instance, illness changes of diabetic patients (sugar level in blood).

Optical response on periodic stress on the high birefringent fibers was studied. The stress frequency was varied in the range from few hundreds Hz to few kHz. Sensitivity of the response dependence on the azimuth of an exerted force was examined. A phase change of the optical response with the azimuth variation was observed. As a result of the study detection of vibro-acoustic signals with a polarimetric sensor was proved.

The refractive indices n_e, and n_o, of thin films of some liquid crystalline substances in the region of the third telecommunication window, at 1.5 micrometer were determined. The thin LC films were applied as optical waveguides and with the m-line spectroscopy the refractive indices for three wavelengths in visible area were measured and then with the Cauchy formula the refractive indices n_e, and n_o, within the field of interest were evaluated.

A spectral-domain white-light interferometric technique employing a low-resolution spectrometer is used for measuring dispersion characteristics of a two-mode elliptical-core optical fiber. The technique utilizes the fact that the spectral interference fringes are resolved at the output of a tandem configuration of a Michelson interferometer and a two-mode optical fiber under test only in the vicinities of so-called equalization wavelengths at which the optical path difference (OPD) in the interferometer is the same as the intermodal or differential group OPD. Measuring the OPD adjusted in the interferometer as a function of the equalization wavelength serves for dispersion characterization of the optical fiber guiding two spatial modes in two polarizations. We measured the dispersion of the intermodal group OPD between the LP_0l and LP₁₁ spatial modes, which were X-polarized or Y-polarized, and the dispersion of the group modal birefringence for the LP_0l and LP₁₁ spatial modes. The measured data were fitted to polynomials to obtain the dispersions of both the differences between propagation constants of the LP modes and the phase modal birefringences.

The Four-Color Matrix method (FCM) was developed to improve the accuracy of chromaticity measurements of various display colors. The method is valid for each type of display having similar spectra. To develop the Four-Color correction matrix, spectral measurements of primary red, green, blue, and white colors of a display are needed. Consequently, a calibration facility should be equipped with a number of different displays. This is very inconvenient and expensive. A spectrally tunable light source (STS) that can mimic different display spectral distributions would eliminate the need for maintaining a wide variety of displays and would enable a colorimeter to be calibrated for a number of different displays using the same setup. Simulations show that an STS that can create red, green, blue and white distributions that are close to the real spectral power distribution (SPD) of a display works well with the FCM for the calibration of colorimeters.

Due to potential of applications, self-trapping of a peak-power laser pulse in a so called filament became an intensively investigated phenomenon. In this paper we demonstrate experimentally advantages of using filaments for the remote laser induced plasma spectroscopy (LIBS). This novel approach can increase effective range of conventional LIBS system up to single kilometers. We also show that Fourier-limited pulse does not optimize LIBS signal, opening the perspective for the pulse shaping techniques in a break-down spectroscopy.

The current status of optical metrology of LCD (Liquid Crystal Display) is reviewed in general and shortcomings of characterization of the visual performance of LCD-screens when high visual fidelity is a prime issue are described. We introduce instrumentation, procedures and evaluations for assessment of the visual properties of LCD-TV screens as a solid basis for a clear and objective rating of their performance. Identification of visual artifacts, color and gray-scale fidelity over the complete viewing-cone and under realistic ambient illumination as well as balanced response times between gray-levels are topics of this paper. A novel approach for scanning of the viewing-directions with simultaneous acquisition of 9 spectra is introduced as a solution for the dilemma of speed of measurement and colorimetric precision.

Our work describes a method for wave-front shape evaluation in microwave range. The evaluation is carried out by measurement and analysis of the interference field that originates from interference of the reference microwave field with the investigated (object) wave field. The phase of investigated microwave field is then determined from values of squared amplitude of the electric field intensity using the phase-shifting technique. The advantage of the proposed method is the fact that the method is based only on scalar measurements of microwave field. The proposed evaluation method is an analogy to phase-shifting interferometry in optical testing, but it uses microwaves instead of optical wavelengths. Due to physical properties of microwaves, the method can be used for various applications in nondestructive testing.

Measurements of very small phase changes in optics are usually performed by interferometric methods on the basis of evaluation of interference patterns that corresponds to a specific phase change of the investigated wave field. If values of the phase change are small, it is difficult to evaluate accurately the phase values, and one needs a very expensive measurement systems. Our work describes a simple method for evaluation of small phase variations that uses the interference of polychromatic light. The phase change has effect on the colour of the interference pattern. Every colour of the interference pattern can be assigned to a specific phase change and it can be evaluated using colorimetric methods, The proposed method offers very accurate results and it is suitable for practical utilization in optical industry due to its simplicity.

Our paper describes a relatively simple method for testing a general shape of optical surfaces (i.e. flat, spherical or aspherical surfaces). The aim of this work is to propose a simple evaluation method that will enable to speed up the testing process of optical surfaces. The proposed method does not require to make a detail analysis of the interference field, i.e. determination of the shape and orders of interference fringes as it is necessary with existing interferometric methods. The deviation of the tested surface from its nominal shape is characterized by a correlation coefficient between the tested wave field and reference wave field that corresponds to the nominal shape of surface. By minimization of the correlation coefficient, one can obtain information about the deviation of the tested optical surface from its nominal shape. The evaluation method is universal and can be used for testing flat, spherical or aspherical optical surfaces.

In the paper the accuracy of a mathematical model of the arterial blood pulse waveform is discussed. The valeus of square means error and correlation coefficient between a pulse waveform and response of its model are given. The methods of model accuracy improvement are considered. The results of numerical adjustment of pulse waveform model are presented.

Camptothecins are fluorescent compounds which exhibit anticancer properties. A disadvantage which seriously limits application of camptothecins in antitumor chemotherapy is the hydrolysis of these compounds. They convert into inactive carboxylate forms. The process of hydrolysis is inhibited when the molecules of camptothecin are bound to cell membranes. So it is desirable that camptothecins molecules bind easily to membranes. A quantitative measure of drugs affinity to membranes is the association constant. To determine this parameter the small unilamellar lipids vesicles i.e. unilamellar liposomes are used as model membranes. The affinities of 10-hydroxycamptothecin and SN-38 to model membranes are determined in this work. Fluorescence spectra of these analogues change in presence of liposomes: the fluorescence intensity increases and besides green band the blue band appears. The spectra of 10-hydroxycamptothecins and SN-38 change over lipids concentration. On the basis of these changes the association constants to membranes are determined.

Optical tomography with narrow laser beam allows for imaging of objects in high scattering medium but with not sufficient resolution and accuracy. In order to improve the method, polarization parameters of scattered light are taken into analysis. In addition a neural network software for processing of data collected during imaging procedure is used. New tomographic method was tested experimentally. As a light source a laser diode module lasing at 660 nm with 35 mW maximum optical power output and internal 2.5 kHz modulation was applied. Intralipid solution in plastic container was used as scattering medium in which a probe with more dense Intralipid solution played role of an object. Scattered light was detected by photodiode with system of polarization analysis and amplified by selective nanovoltmeter. Computer controlled an angular scanning procedure and collected the data from detecting system. After several steps of learning process required by neural software procedure an imaging of placement of object in container was obtained. In conclusion, possible applications of other kind of neural networks are briefly discussed.

The difficulties in accuracy of performed measurements assessment was appeared when author analyzed measurement results of joint space width on the basis of radiographs. It's followed mainly from accuracy of patient position at X-ray unit. So that to solve this problem author worked out methods of elimination measured data of patients for which variation of measurement results was highest (i.e. lowest repeatability of radiographs execution). In this way we can perform fewer radiographs for the others patients to decrease of mean standard deviation of measured data identified with measuring error. Author checked practical application of methods outlying observation reduction and innovative methods of elimination measured data with excess variance at independence as well as dependence of variables. Elaborated methods were verified on the basis of measurement results of knee-joint width space got from radiographs. Measurements were carried out by two methods: directly on the radiographs as well as indirectly on the digital images of radiographs. Results of examination confirmed legitimacy to using of elaborated methodology and measurement procedures. It's solved important problems from metrology, which have application in many medical departments, especially if it's hard to achieve reduction of random error by increase numbers of measurements. Radiology is such a discipline. There is the most essential to reduce ionizing radiation dose for patient during examinations.

Recently surgery requires extensive support from imaging technologies in order to increase effectiveness and safety of operations. One of important tasks is to enhance visualisation of quasi-phase (transparent) 3D structures. In this paper authors present a few of practical hardware solutions using of operational stereoscopic microscope with two image acquisition channels, stereoscopic adapter and Helmet Mounted Display (HMD) for stereoscopic visualization of operational field "in real time". Special attention is paid to the development of opto- mechanical unit. The authors focus on searching cheap, accurate and ergonomic solutions. A few proposals are analyzed: typical stereoscopic adapter with two image acquisition channels equipped with developed software for image low contrast enhancement for stereoscopic observation in stereoscopic HMD of operational field, visual - picture adapter (real operational view through microscope channels or processed operational field images observation in "real time").

The model of laser hyperthermia of cancer of glandular epithelium of bronchi is offered. The conditions for achievement of destruction of cancer are determined. Simulation of processes of interaction of the continuous and pulse laser radiation with a multi-layer biotissue taking into account distribution of energy in laser radiation beam, blood stream, heat transfer, processes of absorption and dispersion are realized. Peculiar properties of hyperthermia of cancer of bronch at laser action are considered.

SERS and MEF phenomena are the result of resonance excitation of localized surface plasmons in nanoparticles of some metals. By adequate choice of shapes and sizes of metallic nanoparticles, kind of adsorbed molecules and wavelength of exciting light, it is possible to achieve enhancement of intensity of Raman scattering equal to 10¹²-10¹⁴. It means that only few molecules inside exciting light beam are sufficient to record the Raman spectrum. Then SERS can be very sensitive tools of trace analysis and very useful in recording Raman spectra of extremely low concentrated biomolecules. The MEF technique can become very useful in study of low fluorescent compounds. In contraire to SERS system for MEF has to be specially prepared to avoid quenching of fluorescence i.e. between the metal nanoparticles and fluorophores should exist the distance layer formed by dielectric or by adsorbed nonfluorescent macromolecules. Increase of fluorescence intensity of low fluorescent compound and possibility of record fluorescence of extremely low concentrated compound cause that MEF can become very promising techniques in biomedical research.

We describe a novel method that estimates the Doppler angle and flow velocity. This method uses en-face OCT imaging and border detection in order to evaluate the Doppler angle. C-scan images are collected at different depths for two particular orientations of the pipe. We evaluate the possible sources of errors in an experiment of intralipid flow at different speeds through a 1.3 mm pipe. Using a FFT signal analyser, we collected at different depths, the Doppler frequency shift due to the axial motion of flow. Knowing the Doppler frequency shift, the flow velocity can be estimated using the Doppler angle achieved applying the method introduced here.

Nowadays biological sensing is representing a very active area of research due to the many possible applications in environmental control, food testing, pharmaceutical screening, and genetic analysis. A particular need exists for miniature biosensors for the detection of proteins, DNA, toxins and, more generally, infectious agents. Several optical techniques have proven to be quite effective, and biophotonics is a continuously growing discipline. Here we provide a quick overview of the recent progresses in the development of optical biosensors based on resonant cavities constituted by dielectric microspheres, where light propagation occurs through whispering-gallery modes (WGMs). The effect of any perturbation to the optical resonance structure of a microsphere is such that a very high sensitivity can be achieved.

Three basic stages towards the global modeling of the eye are presented. In the first stage, an adequate choice of the basis geometrical model, general ellipsoid in this case, permits, to fit in a natural way the typical "melon" shape of the cornea with minimum complexity. In addition it facilitates to extract most of its optically relevant parameters, such as the position and orientation of it optical axis in the 3D space, the paraxial and overall refractive power, the amount and axis of astigmatism, etc. In the second level, this geometrical model, along with optical design and optimization tools, is applied to build customized optical models of individual eyes, able to reproduce the measured wave aberration with high fidelity. Finally, we put together a sequence of schematic, but functionally realistic models of the different stages of image acquisition, coding and analysis in the visual system, along with a probabilistic Bayesian maximum a posteriori identification approach. This permitted us to build a realistic simulation of the all the essential processes involved in a visual acuity clinical exam. It is remarkable that at all three levels, it has been possible for the models to predict the experimental data with high accuracy.

In this work we investigated the photoactive properties sol-gel biocoatings doped with Protoporphyrin IX (PP IX). It was demonstrated that PP IX entrapped in sol-gel preserves it's chemical activity and may have contact with the external environment. The chemical reactions with zinc cations and pyridine, as well as protonation, occurred quite fast. This indicates, that the interconnected porous network could be easily penetrated by relatively large molecules (e.g. mentioned by pyridine molecule). Further, we observed that PP IX molecules do not leave the pores. Structural changes caused by the addition of PP IX to the sol-gel matrix influence not only on the optical properties, but also on durability of the coatings. The altering of PP IX doped silica sol-gel coatings is quite slow.

We describe here the construction of sol-gel based applicators for interstitial thermotheraphy. The silica sol-gel coatings were prepared from silicate precursor TEOS (tetraethylorthosilicate) mixed with ethyl alcohol in acid catalyzed hydrolysis. The matrices were produced with various ratios R=5, 10, 20, 32, 50, whereas R denotes the number of solvent molds (here ethanol) to the number of TEOS moles. The spatial light intensity distribution was examined in order to find out the influence of R factor on the light distribution shape. It was shows that the most homogeneous patterns are observed for sol-gel coatings with R factors equal 10 and 20.

The modification of optical fibers by exploiting various coatings may be important for construction of fiberoptics, sensors or applicators for interstitial laser therapy. We report here on sol-gel films placed on fiber cores, replacing the original fiber coatings. The silica sol-gel coatings where prepared form silicate precursor TEOS (tetraethylorthosilicate) mixed with ethyl alcohol in acid catalyzed hydrolysis. The matrices were produced with various ratios R=5, 15, 20, 32, 40, 50, whereas R denotes the number of solvent moles (here ethanol) to the number of TEOS moles. Two types of coatings were produced: pure sol-gel matrices and sol-gel doped with Protophyrin IX in two various concentrations. The angular light intensity distribution was examined in order to find out the influence of R factor on the light intensity distribution near the fiber tip. Then, the light pattern was captured by means of CCD camera and the three dimensional luminances were calculated. The same experiments were repeated for silica sol-gel coatings doped with natural porphyrine Protoporphyrine IX and different patterns were observed.

In this work, the special portable apparatus was constructed for performing the transillumination examination on interphalangeal joints of patients suffering from rheumatoid arthritis. It consisted of He-Ne laser with optics for collimated illumination, special holder for placing the finger (perpendicular to optical axis, dorsal site towards camera), and CCD camera with memory stick. The captured images in JPEG format with 1152x864 resolution were converted into the gray level pictures and analyzed by means of image processing program from OPTIMAS. 35 ill patients and 11 healthy volunteers were examined. The histograms and 35 luminances were calculated. The average function was applied in order to calculate the mean gray level values in images of corresponding fingers of healthy subjects. These values were compared with values calculated for ill persons. We proved that that transillumination images may have a diagnostic value. For RA suffering patients the corresponding transillumination images represented the lower gray level values than the average value of finger of health volunteers. For II finger of left hand 96% images of ill persons have lower gray level and in case of right hand it was 93%. This proves that basing in transillumination one can diagnose with high probability the patient with rheumatoid arthritis.