We show that coupled Kerr oscillators externally pumped can generate chaotic and hyperchaotic beats. The appearance of chaos within beats depends strongly on the type of interactions between the nonlinear oscillators. To indicate chaotic behavior of the system we make use of the Lyapunov exponents. The structure of chaotic beats can be qualitatively different - the envelope function can be smooth if the system is undamped or can give the impression of noise structure in the presence of strong damping and nonlinear interactions between the individual oscillators. The system considered can be used, in practice, as generators of chaotic beats with chaotically modulated envelopes.

A two level atom driven by a strong resonant field and coupled to a structured reservoir is studied. The generalized master equation describing the evolution of the atom is derived under the Born-Markov approximation. To derive the master equation the dressing transformation on the atomic operators is performed first and next the dressed operators are coupled to the reservoir and the corresponding damping rates are calculated. The modifications introduced by a strong field and/or by the reservoir with non-flat density of modes lead to non-standard terms in the master equation, some of which are reminiscent of terms known for squeezed vacuum reservoirs although the reservoir is not a squeezed vacuum. The optical Bloch equations based on this generalized master equation are obtained and solved for the steady state. The resonance fluorescence spectra of the atom are shortly discussed.

Statistical properties of light generated in nonlinear optical couplers are discussed. Methods suitable for the description of non-classical properties of light are mentioned; special attention is paid to generalized superposition of coherent fields and noise. Regimes suitable for non-classical light generation in various types of nonlinear couplers based on second-harmonic and second- subharmonic generation, optical parametric processes, Kerr effect as well as Raman and Brillouin processes are analyzed. Special attention is devoted to the generation of light with sub-Poissonian statistics, squeezed light, and light in purely quantum states. Role of real effects like damping of optical fields and phase mismatches is also discussed.

We propose a substituting scheme for nonlinear optical couplers operating by means of degenerate parametric down- conversion with strong coherent pumping. The scheme, which provides the same unitary input-output transformation as the original coupler, consists of simple linear and nonlinear optical devices: beam splitter and optical parametric amplifiers. Using group theoretical approach, we find analytical formulas for parameters of these optical elements. The scheme allows us to get a better insight into the coupler behavior, because the complex dynamics of the coupler is transformed into a sequence of simpler evolutions governed by the beam splitter and parametric amplifiers, whose properties are well known and understood.

We investigate quantum phase properties of two-mode optical fields whose quasi distributions have Gaussian form. We show how to simplify calculation of the joint phase distribution defined via radial integration of the quasi distribution related to s-ordering of the field operators. Introducing hyper spherical coordinates, we can carry out analytically one of two required integrations. The second integral over a finite interval is then evaluated numerically. Analytical formula for the joint phase distribution can be obtained in special case of vanishing coherent components of both modes. The general results are applied to analysis of quantum phase properties of two-mode Stokes-anti-Stokes field generated by means of Raman scattering with broad reservoir phonon system and strong coherent laser pumping.

The stochastic simulations of quantum evolution are introduced, alternatively to the Ito-stochastic simulations, for the normal, symmetrical and antinormal ordering in the double dimensional phase-space. The nonclassical effects in the linearized parametric amplifier can be very well simulated in contrast to the collapses-revivals effect in the nonlinear version of amplifier. It is illustrated that the stochastic simulation method using the continuous variables cannot be used if the discreteness of light has pronounced influence on the dynamics.

The chaotical dynamics of two linearly coupled Kerr oscillators is studied. The system is damped and pumped by external time-dependent forces. We show that the chaotic Kerr oscillators can be synchronized and the unidirectional and mutual synchronizations are studied. Phase portraits of the system are presented as well as the time evolution of differential signal of oscillators. The efficiency of synchronization is investigated.

Since reflection or transmission of a quantum particle on a beamsplitter is inherently random quantum process, a device built on this principle does not suffer from drawbacks of neither pseudo-random computer generators or classical noise sources. Nevertheless, a number of physical conditions necessary for high quality random numbers generation must be satisfied. Luckily, in quantum optics realization they can be well controlled. We present an easy random number generator based on the division of weak light pulses on a beamsplitter. The randomness of the generated bit stream is supported by passing the data through series of 15 statistical test. The device generates at a rate of 109.7 kbit/s.

A realistic model for a photon source based on postselection from correlated photon pairs produced by parametric frequency down-conversion is suggested. Its efficiency in producing approximation of single photon states is examined. The application of such source in quantum key distribution schemes is discussed and comparison with currently used sources of photons is given. Future prospects of this type of photon source are outlined.

In this paper propagation of stationary hybrid TE-TM electromagnetic fields through nonlinear Kerr dielectric is considered. The nonlinear material equations are generalized to contain the phase shift between TE and TM components. The resulting system of Maxwell's and material equation is solved numerically. The shape of the field as function of the mechanism of Kerr nonlinearity, propagation constant, quotient of the TE to TM component and phase shift between them is discussed. The solutions of spatial soliton form are thoroughly analyzed. The approximate solution of the equations describing fundamentals hybrid solitons is obtained. The accuracy of the approximation is discussed.

In the framework of the Heisenberg-Langevin theory the statistical effects arising from a mutual interaction of two non-degenerate down-conversion processes are investigated. Primarily, we focus on the possibility to control the intensity and statistical properties of the light generate din one nonlinear medium by the light entering the other one. We also show that the model discussed is an interesting generalization of the famous experiments by Zou, Wang, and Mandel on the induced coherence without induced emission.

We study optical parametric amplification of an attenuated chaotic output beam of a downconverter considering both the quantum single-photon and classical many-photon limits. We compare various correlation measurements of the signal fields.

An experimental comparison of several operational phase concepts is presented. In particular, it is shown that statistically motivated evaluation of experimental data may lead to a significant improvement in phase fitting upon the conventional Noh, Fourgeres and Mandel procedure. The analysis is extended to the asymptotic limit of large intensities, where a strong evidence in favor of multi- dimensional procedures has been found.

To increase the transmission capacity of future communication networks is becoming very critical. This task can only be accomplished by taking advantage of optical networks where multiplexing techniques such as Dense Wavelength Division Multiplexing and Optical Time Division Multiplexing are employed. To avoid electronic bottlenecks a whole new generation of ultrafast devices is needed. To fulfill these needs a new class of all optical devices has been proposed and developed. By taking advantage of the nonlinear dynamics the semiconductor optical amplifiers in combination with the fiber interferometers a new generation of ultrafast all-optical demultiplexers and wavelength converters has been demonstrated. Newly developed broadband optical fiber, a new generation of fiber amplifiers, and extensive progress in dispersion management has helped substantially to increase bitrates and transmission distances in the current optical networks. The latest technologies in the area of micro-machining have created very attractive low cost MEMS. Recently announced use of bubble technology for all-optical switching might also lead to the development of next generation large scale switching fabrics. In this paper we discuss progress and new trends in some of these areas.

We discuss possibilities of quantum manipulations of trapped ions from the perspective of quantum information processing. We show how from a restricted set of feasible microscopic interactions a physical implementation of an arbitrary unitary operator can be realized. An example is given for the discrete Fourier transform. The synthesis of operators enables to realize universal quantum gates to process unknown input qubits which can be encoded into vibrational levels of trapped ions. We discuss also problem of an arbitrary measurement which can be performed using quantum gates.

Application of incoherent holography for achievement of the depth-discriminated microscopic imaging was proved. The image quality described by the coherent transfer function is comparable with that of a conventional confocal microscope; the imaging speed can be substantially higher. The observed plane is imaged as a whole, continuously in time, without any scanning system. Besides the amplitude, the phase of the confocal image is reconstructed, carrying information about phase shifts inside the specimen. The depth discrimination property can be enhanced beyond the capability of a conventional confocal microscope by the use of a broad-band illumination.

Electronic speckle pattern interferometry pioneered 30 years ago, represents one of the most powerful tools for industrial nondestructive testing and metrology. Main advantages include speed of data acquisition and processing, relative simplicity and possibility to work outside the laboratory. Steady progress in optoelectronics, fiber technology, and informatics facilitates the development of compact and robust systems for new tasks in engineering analysis.

The presented paper deals with the usefulness, applicability, effectiveness and other aspects of the exploitation of laser interferometry and holographic/speckle interferometry optical setups in the field of experimental mechanics. By describing of several examples an incomplete review is given about the basic principles of these 'classic' optical techniques. The basic optical schemes are described and a few interferograms, obtained at the testing experiments with mechanically loaded structural elements, are presented. Also, the evaluating principles of the stress state are presented, which are as a rule inevitable when solving the problems in mechanics of solids.

In this paper, the causes of nonlinearity of a laser interferometer with a single-frequency laser and a detection system with two signals in quadrature are described. Several methods of nonlinearity measurement are presented. Experimentally was tested a method with a linear mechanical shift and a method of linearity measurement using optical resonator. When using linearity compensation by means of a PC program, a deviation from linearity in limits of +/- 0.5 nm for the linear mechanical shift method was achieved. The preliminary results recorded during the linearity measurement with the optical resonator are below the limit of +/- 1.0 nm.

The effect of a detecting system consisting of a monochromator of a variable spectral bandpass and a broadband detector on time-domain and spectral-domain two- beam interference in a Michelson interferometer is analyzed theoretically and experimentally. The time-domain theoretical analysis of the two-beam interference shows that the visibility function for the spatial interference fringes, that is, the visibility of the spatial interference fringes as a function of the delay in the interferometer, is affected by the bandpass of the monochromator. Similarly, the spectral-domain theoretical analysis of the two-beam interference gives the visibility function for the spectral interference fringes that varies with the bandpass of the spectrometer. The time-domain theoretical conclusions are confirmed experimentally in the Michelson interferometer configuration using a TOLD 9140 laser diode operated below the threshold and the detecting system of the variable spectral bandpass consisting of a prism or grating monochromator and a PIN photodetector. The spectral-domain theoretical conclusions are confirmed experimentally using the TOLD 9140 laser diode and the prism or grating spectrometer, and using the TOLD 9211 laser diode and the grating spectrometer. The measured time-domain and the spectral-domain visibility functions are also used to obtain the reciprocal linear dispersion of the monochromator or spectrometer.

Spectral-domain optical interference phenomena for broadband spectra take in the case of a two-beam interference the forms of the spectral interferograms. The group optical path differences between interfering beams that include information about the distance to be measured and about the properties of propagating wavefronts are inscribed in phase functions of the corresponding spectra interferograms. To recover the phase functions, a standard Fourier-transform method, or a new, recurrence non-linear data processing method can be used.

Cylindrical optical elements play an important role in processing diode laser beams. Alternatively, diffractive elements can be used especially if they are simply holographically recorded. Analysis of the holographic recording process of elements transforming beams with spherical wave fronts into beams with cylindrical wave fronts is presented. Only rotationally symmetric beams can be used for recording. Four equations provide four unknown parameters. Two examples were realized: one for transformation of a divergent beam with a spherical wave front into a cylindrical divergent beam with a cylindrical wave front the focal line of which lies in the meridional plane and the other for transformation of a collimated beam into a convergent beam with a cylindrical wave front with the same property of the focal line.

This paper presents a contribution to experimental methods to determine anisotropy of a uniaxial plate-shaped material with the optic axis parallel to its surface. Some preliminary observations and considerations dealing with a thick holographic phase grating anisotropy are included.

In this paper the diffraction of Gaussian beam with optical vortex by simple object is considered. The calculations are based on the scalar, near field diffraction integral. The dynamics of the optical vortex within the diffracted wave front is analyzed in particular.

The subject of the paper is the presentation of applications of the full-field heterodyne interferometer. The description of the interferometer used is given. The basic relations for the fast CCD Dalsa camera are cited. The sources of the measurement errors are discussed. The result of testing the frequency difference stability of acousto-optic modulators are described.

The practical problem of the lack of quarterwave plate for arbitrary wavelength has been solved. It has been shown that is possible to substitute this plate with a combination of two phase plates with phase shift different from 90 degrees. Some formulae have been derived for several of the most important cases of wave plates application in measurement setup. All the formulae are valid for arbitrary phase difference of component plates.

Numerical modeling of wave propagation in anisotropic single crystal is based on the angular spectrum technique. The decomposition of initial acoustic signal distribution into its angular spectrum is performed by the calculation of 2D Fourier transformation. Phase shift of each harmonic plane wave component depends on the distance between initial and observation planes and the normal component of the wave phase slowness vector. In anisotropic media slowness depends on direction of propagation vector and on polarization. In acoustics directionally depending phase velocities are calculated from Christoffel equation. Decomposition of initial distribution and superposition of plane waves in observation plane is performed by the use of FFT algorithm. One may use this procedure in forward or back propagation. Here we use this technique for reconstruction of point source and a structure located inside of a single crystal. The complex data sets of synthetic aperture type were measured by scanning ultrasonic microscope with phase contrast.

The interferometric measurement method of a thin film optical thickness is presented in this report. This measurement is realized by Michelson's interferometer. Interferogram of a measured sample with one half of the surface covered by a laser and the other without a layer is digitally recorded from the screen by CCD camera. The video- signal from two rows of the intensity distribution from the part with and without a layer are numerically filtered via fast Fourier transformation and the phase change of the two periodical 'continuous' functions is evaluated by the first and second derivatives. This phase change allows to determine the path difference and finally the optical thickness of the layer.

In this contribution, a new mathematical procedure enabling us to calculate the optical quantities of the inhomogeneous thin films such as reflectance, transmittance and ellipsometric parameters will be described. This procedure is based on combining the known matrix formalism and Drude approximation. The inhomogeneous thin films is replaced by a multilayer system containing the thin films with a linear profiles of the dielectric function and different thicknesses. Every individual film of the multilayer system is described by the matrix corresponding to the Drude approximation. Using this procedure one can construct an efficient algorithm allowing to calculate the values of the optical quantities of the inhomogeneous thin films exhibiting great gradients of the refractive index profiles.

The fluorescence detector, a component of the AUGER project, is designed to observe fluorescent light generated in interactions of high energy cosmic rays with nitrogen atoms in the Earth's atmosphere. This article present several designs of optical filters transmitting in the range 300 nm- 420 nm, where the fluorescent light is emitted. Two approaches are proposed: a system of thin dielectric layers and a combination of suitable glass plate. Quality of different filters is determined according to the value of transmittance in the required wavelength range, the shape of the transmittance curve at the edge of the transmitting window, long-term stability as well as feasibility and cost of their mass production. Selected types of filters were prepared, their parameters measured and compared with predicted values.

The periodic self-reconstruction of the transverse spatial intensity profile of the coherent monochromatic wave field and the spatio-temporal self-reconstruction of the wave packet are analyzed. We present both the theoretical description of the effect and the approximate model related to the experimental realization. Applications of the self- reconstruction resulting in the beam self-guiding and the self-imaging are also discussed and demonstrated in numerical simulations.

TM-modes coupling in an magneto-optic waveguide caused by periodic perturbation of the interface have been analyzed. Introducing into waveguide structure a gryotropic material gives an additional 'degree of freedom' namely external magnetic field. Using the coupled-mode theory the problem of mod interaction is reduced to a pair of coupled equations. Coupling between the modes propagating in the opposite direction is analyzed. When the approximate phase matching condition is satisfied, the incident TM mode power decreases exponentially along the perturbation region. This evanescence behavior is the result of the distributed 'reflection' of incident power into the backward traveling TM mode. The evanescence behavior occurs for a range of frequencies called 'forbidden' zone in which the propagation constant has an imaginary part. In magneto-optic waveguide the center frequency of the gap can be easily controlled by external magnetic field.

The results of modeling spectral characteristics of modal birefringence and its sensitivity to temperature using different approaches for calculation the residual thermal stress are presented. The modeling was carried out using the modified perturbation approach first proposed by Kumar.

The commutation of optic signals is an important operation for photonic and telecommunication systems. The switching integrated optic circuits permit to increase power of integration of hybric IOC and to unite different IOCs for the creation of a photonic system. The waveguide switching acousto-optical IOC on 4 by 4 channel is presented.

A fiber-optic sensor for simultaneous measurements of pressure and temperature is presented. The sensor is based on highly birefringent fibers and uses coherent addressing principle to retrieve information about changes of the two parameters. The bow-tie fiber is used as a temperature sensing element while information about pressure changes is decoded from the differential pattern produced by the side- hole and the bow-tie fiber. The sensor characteristic and responses to simultaneous changes of pressure and temperature are demonstrated.

The theoretical analysis of second-order magneto-optical effects is presented. A material anisotropy is introduced by relative permittivity tensor whose components are expressed using Voigt magneto-optical parameter Q and Lissberger's parameter f. The permeability corresponds to isotropic medium. Three principal configurations are studied according to the magnetization-transversal, polar and longitudinal. The governing wave equation for the field vector leads to four polarization states described by complex polarization vectors. Their components have been derived in closed form. The eignemode polarization states in planar structures with magnetic ordering for the classical materials applied for magneto-optical media are analyzed in detail.

Asymptotic solution to estimate single mode fibers splice reflection attenuation is proposed. The basis of calculation algorithm is approximation of splice zone by sectionally regular weakly guiding single model lightguides. A fiber waveguide Gaussian approximation to determine lightguide parameters of each section is applied. For model being investigated a generalization of known from the guiding system theory recursion solution for equivalent reflective coefficient is used. Model of splice of single model optical fibers and algorithm of calculation are described. The results of calculations being depended of mode field diameter range and length of splice zone for splice of optical fibers with typical parameters are performed.

Realization of the optical frequency laser standards is the basis of the length metrology. In accordance with the mise en pratique of the definition of the meter there is possible to realize the length unit by means of one of twelve recommended radiations listed in the Recommendation I issued by the CIPM. Technical progress in the laser diode development enables to apply these elements as the length standards. Our article is devoted to the thermoelectric tuning of the laser diode frequency.

For a fundamental etalon of optical frequency based on the external-cavity semiconductor laser (ECL), not only the long-term frequency stability but also the linewidth seems to be an important parameter. The linewidth broadening is dominated by fluctuations of the optical frequency. Parameters of these fluctuations and their spectral characteristics are crucial information for their suppression. We present an experimental setup for the frequency noise measurements designed for a free running 633 nm ECL with a stabilized reference He-Ne laser. We observed the corner frequency of the 1/f noise of the ECL of approximately 10 MHz. No significant spectral components over the 1/f noise corner frequency were found.

The optical intensity distribution is theoretically studied in a double-heterostructure (DH), Al_xGa_1-xAs- GaAs material system using PICS3D software simulation. The electrical and optical equations to describe the behavior of semiconductor lasers are reviewed. To investigate the optical and carrier confinement in basic DH, the index x of AlAs mole fraction is varied. From computational results and technological considerations, index x 0.35 is chosen for a dielectric slab waveguide. In order to accomplish optical and electrical confinement in the lateral direction, oxide- stripe and ridge waveguide geometry is treated. The light verus current characteristics, electron concentration profiles, optical intensity distribution, as well as current flow are evaluated. Finally, it follows from the computed characteristics that optical and carrier confinement in transverse and lateral directions is accomplished for ridge- waveguide geometry with a ridge height of 540 nm.

For the study of the longitudinal mode structure of semiconductor lasers, a diagnostic method is needed in which the spectral resolution is many times better than the distance between the adjacent longitudinal modes. A diagnostic method based on the high-resolution spectroscopy, the lock-in detection technique and a specially designed software package has been developed. The measured spectra of a semiconductor laser show that the method describes the spectrum with sufficient spectral and signal resolutions.

We present experimental results obtained by deposition of single layer and double-layer system made by means of electron-beam vacuum evaporation technique. We oriented our effort to short-wavelength 635-633 nm laser diodes emitting close to the wavelength of traditional He-Ne lasers with an intention to use them in extended-cavity laser design for metrological purposes. The resulting reflectivities were evaluated by measuring a testing plate of GaAs and by measuring a 'modulation depth' of a coated diode emission spectra. Our best results were reflectivities well below 10^-4 and the repeatability of the deposition process in a range not exceeding 2 by 10^-4.

We present a tunable extended-cavity semiconductor laser system based on the Littman configuration emitting in the visible region of spectra with the wavelength close to the 633 nm of He-Ne lasers. It has been frequency stabilized to Doppler free hyperfine transmission in molecular iodine. The stability was measured compared to the reference He-Ne-I₂ laser system, the present most commonly used laser primary standard. While the semiconductor laser was locked on components of the P(33) 6-3 transmission close enough to the reference R(127) 11-5 line to arrange a beat frequency counting. A relative stability of 4 by 10^-12 over a 100 s integration time was achieved. The laser configuration allowed a mode-hop free tuning over a range including a group of strong overlapping transitions R(60) 8-4, R(125) 9- 4 and P(54) 8-4 with higher signal-to-noise ratio.

This paper builds on the general theory of determination of the small deformation tensor by means of the method availing the statistical properties of speckle pattern propagating through free-space and image-field. It concentrates on vibrations determination in the direction of the normal to the object surface plane. In the first part of this paper the basic theoretical equations are mentioned, next some experimental configurations are designed for the measurement of the normal vibrations of an investigated object with a rough surface, finally the analysis of sensitivity and accuracy is done and some experimental results are also presented.

The basic behavior of microparticles placed in the Gaussian standing wave is studied theoretically in this article. It is shown that the optical force depends periodically on the particle size and, as the consequence, the equilibrium object position is alternating between the standing wave antinodes and nodes. It is presented that the particle confinement is disabled for certain particle sizes. Simplified theoretical description giving analytical formulae for weak dielectric spherical objects of micrometer sizes is presented. Coincidence with the generalized Lorenz- Mie theory is studied here. Experimental confirmation of the theoretical results is briefly discussed.

One marked the field of radiation of the electric dipole and next cross section on scattering. One analyzed the scattering lights on molecules not possessing of own dipole moment and then polar small particles. Treating the small parts of dust and of suspensions as elementary centers of scattering gone measured the angle distribution of scattered light intensity for selected size of particles. During measurements one used a monochromatic laser light researching scattering process in range of angle from 5 to 175 degrees.

The scanning table, which is controlled by a PZT control system that has been constructed, is presented. It is used for a fine manipulation of a probe in measurement of the profile of the laser beam focused by high NA lens e.g.. The whole system has been calibrated by a two-axis laser interferometer. Where the PZT control system and the interferometer were connected to the CAN network and the actual X-Y position was saved to the PC synchronously with the CAN network time stamps generated by the PZT control system. Precision about 300nm at the positioning system was reached.

The topic of this paper is theoretical consideration on utilization of light scattering for measurement of surface roughness. We use correlation of laser speckle fields generated by light of two different wavelengths, which illuminates investigated randomly rough surface. We present the solution of the problem within the framework of the scalar Kirchhoff theory of wave scattering from random rough surfaces. We use the Fresnel approximation in description of the scattered wave. Our solution is a contribution to the Kirchhoff theory of electromagnetic wave scattering from random roughly rough surfaces.

The harmonic nature of the potential well for the small displacement of the probe from its equilibrium position allows us to classify the trap characteristics with three independent spring constants. These can be obtained from the spectral analysis of the thermal noise of the particle position. Probe position in all three dimensions is monitored with a single quadrant photodiode placed in the back focal plane of the microscope condenser. Experimental results of the trap stiffness measurements are presented.

The paper describes a conception of an instrument for remote detector of carbon monoxide in free atmosphere which utilizes differential absorption of optical radiation. The CO molecule strongly absorbs in the band centered at 4.7 micrometers . The goal of the present effort is to build an instrument capable to detect both low and high concentrations of CO. The key problem is that absorption of CO, for a length of measuring path greater than 200 m, is saturated even at non-lethal concentration. In this case it is not possible to use the simplest concentration of an optical remote detector and it is necessary to measure absorption spectrum of the atmosphere, at least in the region from 4.4 micrometers to 5.0 micrometers .

In this paper, there is described the influence of various modifications of the laser resonator on the energy of laser radiation studied for the application of material drilling. We used pulsed 150W Nd:YAG laser from LASAG AG company, Switzerland. This laser was developed for industrial material processing - cutting, welding and drilling. The diameter and divergence of the output laser beam can vary by replacement of optical elements in the laser resonator and by change of the distance between them. Heating of Nd:YAG crystal during laser action resulting in its function as an internal lens has an important effect on a beam quality. This quality is characterized by a beam parameter product depending on a charging power and type of resonator. The goal of our experiment is to find minimal parameters for cutting and drilling of some metallic sheets with thickness from 0.1 mm to 10 mm and to verify an increasing beam quality by reducing a laser output power and by modification of a resonator arrangement. Nitrogen was used as an assist gas. Measured experimental results were summarized in graphs and tables and were prepared for quick reference of laser parameters used for processing various work-pieces.

The cornea does not play any significant role in accommodation and is not expected to alter in curvature during the process. Nevertheless, some residual shape change may occur. In this paper we present preliminary results of a study in which we looked at the shape of the cornea for two separate accommodative states. Corneal power was measured with a Javal keratometer in tow states of the eye on one eye each from 12 emmetropic subjects aged between 20 and 28 years. These results suggest that there may be slight changes in central corneal curvature with accommodation.

Human beings receive predominant percentage of the information about the environment thanks to their sense of vision. Therefore the vision quality is one of the most important parameters determining our well-being. By the vision quality we understand the possibility of perceiving light and darkness, colors and shadows, differentiating details form background and recognition of various objects. Vision quality depends on number of factors connected with the optical system of an eye, the light detection by retina, transmission of neural signals from eye to brain and the psychological process of signal interpretation. Vision quality is thus a complex idea.

The method of the measurement of the corneal topography was worked out. This measurement system uses an interferometer based on radial shearing. This paper presents the preliminary results of the experiments. The results are compared with other methods.

In this paper, it has been shown an apochromatic triplet can be designed without employing special glasses. This possibility is offered when optical system is composed of two lenses, i.e., hybrid and glass ones. Such a system is proposed and its spherochromatic aberration is determined. Aberration characteristic of the system is compared with that of conventional glass apochromat.

This article presents the proposal of two new methods of the statistical and computer evaluations of the iris structure of a human eye in view of personal identification, based partly on the correlation analysis and partly on the median binary code of commensurable regions of digitized iris images. The results of the measurement by the mentioned methods are presented, compared and evaluated subsequently.

The recognition of a unique human iris structure belongs among the most investigating biometric methods of a person identification at present. The results of two tested modified evaluating methods for a possible indirect identification of person by means of Fourier spectra of the optical transmission binary models of irises are presented in this paper.

Special equipment was realized for measurement of biomechanical characteristics of samples of lower part of the spine that means the lumbar part L1-L5. The measuring was carried out on 3 spinal samples. At first on an intact spinal sample, on a destabilized spinal sample and on a stabilized spinal sample. The stabilization was carry out by cylindrical cages and fixation screws. Using force-meters each specimen was tested sequentially nondestructively in axial torsion, compression, flexion and extension and lateral bending. Stiffness of destabilized and stabilized samples were computed to that of intact spine. During straining and measurement of ht rigidity of the sample as a whole it is also necessary to observe the movement of individual parts of the sample. This movement is followed with the help of round targets connected to the appropriate vertebra to be observed. The detectional targets are lit with a lamp, in some cases with a laser, and are watched by two CCD cameras. An optical signal is brought into a computer and evaluated by the fast Fourier transformation method. The period and direction of interference fringes determine the size and the direction of the shift.

Recently, the use of far IR spectral region (FIR), especially in range 8-13 micrometers , is widely discussed. One of the main areas of applications is monitoring of human body for health care. On the other hand, the health care and banking industries are faced with fraud. There is a need to elaborate the systems that can be used not only for health diagnosis, but also for unique identification of human bodies. This paper discusses the possibility of exploiting of the registration of FIR images and their computer aided processing for facial recognition systems.

Excitability, i.e., a large-amplitude response to a super- threshold perturbation while a sub-threshold perturbation leaves the system almost unchanged, is the key property of neural cells of the retina of human eye. Basic terms are introduced and the dynamic behavior under single-pulse and under periodic perturbation is discussed in detail using the firing ratio as a function of the perturbation amplitude and of the perturbation period forming a 'devil staircase' structure.

The realized equipment for measurement of the granularity of black-and-white and color photographic materials is based on low-speed rotation of the optically transmitting granularity sample and microphotometrical scanning of its image. The obtained electrical analogous signal is amplified and converted to the digital form by an analog-to-digital converter and the processed by a special computer system. It is a modern digital-microphotometrical rotational granulometer with originally designed mechanical sample stage and electronical processing system which is useful for the laboratory practice. Its outputs consist of random optical transmittance data of the granularity sample under measurement their mean value and dispersion.

The main aim of this paper is a presentation of a new method, being a consecutive attempt to describe the excitations into condensed systems. Using the Fourier analysis, the author tries to combine the quasi particles theory with quantum Schrodinger equation obtaining in consequence series interesting results.