Dynamics of vertical-cavity surfac-emitting injectio lasers (VCSEL) was simulated. The model of VCSEL is based on the set of self-consistent differential equations in partition derivatives and material relations for quantum well structure. An optical field in active resonator was numerically obtained by effective frequency method in cylindrical coordinates. The variables separation method was used for 3D wave equation resolving. An optical field outside laser mirror was calculated by Fresnel integrals. Two-mode self-pulsing regime at approximately 2 GHz repetition rate was observed at bias current value of about twice threshold. The obtained near- and far-field dynamical behavior of LP01 and LP02 lateral modes represented the processes of spatial energy exchange between the two modes as well as between the parts of particular mode. In the vicinity about of 20 microns near output VCSEL surface (diffraction zone) the sharp spatial oscillations of optical field in the center of beam were observed. It was shown that the above dynamical processes are caused by non-uniform carriers rearrangement in active layer.

Novel photoelectric techniques of characterization of semiconductor laser and photodetector materials have elaborated. The measurements of photodiffusion current spectra allow to determine not only the photoionization energy of impurity centers and intrinsic defects but also the type of the photogenerated carriers. In this work for the first time we have also developed novel and efficient technique for characterization of nonlinear and laser materials by using a time-resolved photoelectric spectroscopy. This make possible to study the processes of trapping and detrapping of photoinduced electrons. Mentioned above techniques was used for characterization of energy structure of defects and transport of carriers in the photorefractive CdTe:V crystals.

Fivefold decrease of RMS jitter of 1 pps pulse from GPS receiver after SA switch-off and relatively short period required to filter it out has enabled the construction of GPS synchronized frequency sources of parameters almost order of magnitude better than with SA. New design challenge has been to achieve 10^-11 frequency accuracy over time period of 1000 seconds. Basic block diagram of GPS disciplined frequency source is presented in fig 1. The only non purely digital blocks of the source are quartz oscillator and digital to analog converter D/A and their specs decide about the parameters of the output frequency signal. Design requirements for internal quartz oscillator as well as digital to analog converter based on required minimal frequency control loop time of about 10000 seconds have been derived and presented. To summarize, quartz oscillator has to exhibit aging not worse than 3 • 10^-11/24h and temperature coefficient 1•10^-12/°C while digital to analog converter has to be an 18-bit device with 1 LSB differential nonlinearity and extremely low temperature coefficient. Alternately as devices with very low temperature drift are very expensive, the converter can take its reference voltage from the oscillator, where the reference source is temperature stabilized. This of course places higher demands on the oscillator voltage reference source.

The main mode lateral field excited resonators exhibit high value of motional resistance and very low value of motional capacitance. One undesirable property of these resonators is difficult frequency calibration and oscillator frequency adjustment. The anharmonic mode resonators exhibit lower motional resistance and few times higher motional capacitance. Because of that frequency calibration and frequency adjustment in oscillator is significantly easier. Different versions of SC 301 and 310 mode resonators have been designed and elaborated over past several years. The result were optimized practically versions of 301 and 311 mode resonators. For lateral field excited resonators the double oven OCXO oscillator was designed. The resonators were mounted in oscillators. Next the short term stability, long term stability and thermal stability of oscillators were measured, using conventional methods of measurement. The long term frequency stability measurements were carried out in laboratory with ambient temperature stabilization in the range 20 ± 1 °C. The oscillators exhibited long term frequency stability below 2 E-11 per day and short term frequency stability below 8E-13 per second. The analysis of the oscillator parameters measurement showed main influence on them not resonator quality but the oscillator construction and utilized electronic components quality. The result of analysis of these parameters was the new design of hermetically sealed oscillator with carefully selected electronic component. The oscillators were hermetically sealed for prevent of environmental conditions.

The effect of doping with CuI and NiI₂ on non-linear optical properties of CdI₂ crystals was studied. The change of non-linear optical properties of these crystals caused by the ordering of admixture centers was investigated. The ordering was achieved by the interaction of the orienting magnetic field and the membrane oscillations of the lattice with the admixture ions located in the inter-layer space.

Basic problems of relaxed optics are discussed in historical, theoretical and experimental retrospective and perspective. The classification of basic relaxed optical phenomena are discussed. The way of possible development the relaxed optics in exeperimental and theoretical directions and its possible applications are discussed too. Few models of irreversible interaction light and solid in self-absorption range are represented and analyzed.

The influence of defocusing value on the effectiveness of the laser method of vibration parameters measuring is shown in this work. The analysis is made using mathematical modeling and physical simulations.

The theory of electron, hole and exciton spectra in the opened complicated spherical quantum dots (QD) in the medium is developed in the framework of the S-matrix method. The main properties of the quasistationary states are analyzed for the particular heterosystems. The ability of quasiparticle localization in the different shells of the system.

Light bullets i.e. ultra short spatial-temporal solitons propagating in the Kerr nonlinear media are investigated in the framework of the paraxial approximation by means of both aberrationless approximation and variational approach. It is shown that oscillatory light bullets of picosecond and femtosecond ranges may be stable for significant distances in the Kerr media. Different possible modes of propagation are investigated, critical threshold values of the energy of the pulse defining the limits of these modes are found. Exact expression for the focal distance of the collapse is found in the (1 + 2)-dimensional case.

The aim of this work is to illustrate features of computation for MQW strained semiconductor lasers based on type-I and II heterostructures. The theoretical results founded on the given distinctions allowed to investigate the threshold current temperature dependence and research the behavior of all its components for InGaAsSb/AlGaAsSb and InGaAsSb/GaSb heterolasers which we have chosen as examples of type-I and II heterostructures respectively. The obtained data and additionally carried out computations assure that further threshold current optimization will result in its lowering.

We report on the growth by MBE and characterization of optically-pumped mid-infrared Vertical Cavity Surface Emitting Lasers (VCSELs), where the optical cavity is formed by a semiconductor Sb-based Bragg mirror, an air gap and a high reflectivity dielectric concave mirror. These lasers operate between 2 μm and 2.5 μm in continuous wave regime at room temperature with a circular TEM₀₀ beam. Two different fabrication processes are tested and the properties of the corresponding devices are compared.

Raman, spectroscopic and laser investigation of new multifunctional Nd³⁺:SrWO₄ laser active and Raman crystal are presented. Efficient intracavity stimulated Raman scattering in Nd³⁺:SrWO₄ laser was obtained at 1.16 μm.

We present a full set of the solution of the parabolic wave equation in the form of mode beams with the eigen polarizations. The theoretical analysis showed that the paraxial fundamental Gaussian beam can transform into a singular beam bearing the double charged optical vortex: the left-hand circularly polarized beam converts into the right-hand polarized beam with a positive topological charge whereas the right-hand one generates the left-hand polarized beam with a negative charged vortex. Moreover, the device can transform high-order singular beams in such a way that the negative topological charge of the vortex in the right-hand polarized beam raises by two units but the positive vortex charge in the same beam diminishes by two units.

New type of gain flattening filter for WDM systems is considered. It is based on the use of nonlinear Fabry-Perot interferometer as an amplitude mask in the Fourier-synthesis of short optical pulses. Results of numerical simulation show that the flat broadband gain spectrum of EDFA can be obtained in the proposed scheme by means of applying additional holding beams of mW powers.

As well known, rectangular Hermite-Gaussian modes as well as cylindrical Laguerre-Gaussian modes do form an orthogonal set endowed with shape-invariance properties. So they can form an expansion basis for many propagation-invariant wave fields in the paraxial regime. Especially for those coupled from laser resonators or oscillating inside. In this contribution, is addressed the determination of the sufficient number of modes in the expansion for both sets and in different aperturing kinds: hard, soft and moderate.

The holographic methods of phase micro-objects visualization (the holographic phase contrast method and the method of holographic interferometry) are considered. Comparative analysis of classical and holographic methods in microscopy of phase micro-objects is carried out. An arrangement of the holographic interference microscope realizing the holographic methods and experimental results of 3-D imaging of native blood erythrocytes are presented. It is shown that 3-D morphology of blood erythrocytes reflects and determines the state of a human organism and those different physical and chemical factors and internal pathologies influence erythrocytes morphology. The holographic interference microscope was used for investigation of ozone therapy influence on human blood erythrocytes. Blood samples of 60 patients of different age with neurosensoric hardness of hearing before and after ozone therapy were investigated. It was shown that all patients have changed erythrocytes mrophology. Ozone therapy treatment results in normalization of erythrocytes morphology of patients.

Deep insight into thermal effects in the broad-area lasers is the main condition of obtaining the improved devices. We present the analytical solution of the two-dimensional, stationary heat conduction equation yielding the temperature profile in the laser cross-section in plane parallel to the mirrors. Our approach allows for considering various heating mechanisms and assessing their contribution to the total temperature of the device.

Design of all-optical packet switch with time division multiplexing for channel level of DWDM fiber networks is presented. Main feature of the device is the realization of data buffer on the basis of transverse interconnects within the 2D-array of optically bistable pixels. Functionality of key components of the switch is shown experimentally. Applications of such a device are discussed in the context of data rates and network services.

Dynamics of the mean amplitude of oscillations of a crystal oscillator with a linear feedback is outlined for low drives when the losses (friction) of a resonator become large and nonlinear after a long storage. The drive-level-dependence (DLD) of the crystal resonator losses is assumed to change inversely to the piezoelectric current. A stochastic differential equation for the mean amplitude is derived and solved in a sense of Ito. The development and attenuation processes are learned and it is shown that attenuation finishes at some non-zero level associated with the effect termed "sleeping sickness." The critical value of the friction is calculated and the conditions are discussed to avoid attenuation. Based upon, we show in that (1) if the value of the DLD coefficient of the resonator losses ranges below the critical point, the effect occurs primarilly in a delay of self-excitation; (2) contrary, noise drives the crystal oscillator.

We present the generalized asymptotical model of a single-mode crystal oscillator with a nonlinear resonator. The motional and static equivalent parameters associated with the fundamental mode of a crystal resonator are assumed to be drive level dependent (DLD) and flicker noisy. A thermal noise of the resonator losses is also taken into account. A concept of the feedback amplifier is discussed resulting in a series branch of the equivalent resistance and inductance (both flicker-noisy and negative) along with the thermal additive noise source. The generic differential equation of the second order is derived, in which the auxiliary sub-functions are introduced being responsible for the equilibrium, anisochronisms, thermal noise (additive and multiplicative) effect, and colored (flicker) noise effect. We show that such a model covers all three special ranges of the piezoelectric current, namely those with low, normal, and high drives.

In this paper, exact analytical Helmholtz bright and dark soliton solutions for a Kerr nonlinearity are presented. Numerical simulations verify that these solutions are both robust and act as attractors in nonlinear beam dynamics. Results dealing with the coherent interaction of Helmholtz bright solitons are also presented, for the first time. These considerations extend previous (paraxial) studies that are only valid for vanishingly small interaction angles.

The temporal shape of ruby laser pulse is experimentally investigated in the cavity typical for the intracavity processing of Al-film evaporated on the glass substrate. This results in forming of the train of nanosecond pulses with nearly 100% modulation. It is shown the possibility to form nano-sized periodic surface structures by single-pulse ruby laser treatment.

While Internet traffic increases dramatically and now it exceeds the almost stable voice traffic, new efficient solutions for network architecture are sought. One of the main problems to be resolved is the basic concept of the future network performance. While actual networks are based on 'circuit switching' connection networks with IP packets forwarded given the network offers some free resources, a number of researchers foresee the future network as a 'packet switched' connectionless network which would support also the traditional real time services with phone calls as the most representative example. This is driven by the growing use of voice over IP services. Unfortunately, the Quality of Service is actually not sufficient for wide acceptance of that technique. In fact, Internet is based on the 'best-effort' principle in what it fudamentally differs from circuit-switched network which has been developed uniquely to provide excellent voice quality during last century. Moreover, the reliability of the network is a crucial factor in emergency communications, what has recently became a subject of intense activity at national and international scale. As a consequence, the idea of dropping the converged network with voice-over-IP concept is hard to accept for a great majority and those expressing it are usually looked as strange or even dangerous individuals. Nevertheless, those fundamental difficulties become obvious for a growing number of people who approach the future network evolution more fundamentally, and try to trace reasonable and economic ways of the future network development. The author of this paper has extensively developed a concept of a "hybrid network" which consists of real-time subnetwork and packet network separated in the optical frequency domain that will be discussed in detail in this paper. This optimized network concept is intended to guarantee both reliability of the network and Quality of Service as well.

The semiconductor laser is commonly used as a light source in fiber-optical telecommunication systems. In order to send as much information as possible in a short time, it is important that the laser has a large modulation bandwidth, i.e., the turn-on and turn-off time should be as short as possible. In analogue fiber optic systems for transmission of radio or television signals, it is also important that the light from the laser increases linearly with driving current even at high modulation frequencies. Otherwise, the transmitted signal will become distorted. The modulation bandwidth and the modulation distortion are dependent both on the laser structure and the gain characteristics of the active material. One of the most useful approaches for the time-domain description of the response of optoelectronic devices is the so-called "rate equation model," which has been widely used to describe laser performance. Commonly, laser models with simple gain expressions are used for simulation of laser dynamics. In these models the small-signal dynamic parameters like the differential gain and gain saturation parameter are extracted from modulation response measurements. However, we show that in order to correctly calculate distortion, an accurate model of the dependence of gain on carrier density, n, and photon density, s, is needed. Commonly used gain models, fitted to give exactly the same modulation response can give significantly different distortion behavior.

Some possibilities of simple and thus reliable schemes of experiment "self-control" exploiting intrinsic features of studied non-linear phenomena like wave front reversal under stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS) and coherent anti-Stokes Raman scattering (CARS) rather than outer sensors and controls are described. The schemes discussed provide input signal dynamic region broadening in stimulated scattering converters and angle of synchronism self-tuning while two frequency pumping.

The methods of geometrical optics are of a great importance of calculation of wave fields in inhomogeneous surroundings. In particular, the applications are extremely interesting in correspondence with description of extending and radiation of light waves in inhomogeneous lens devices and also in waveguides with inhomogeneous filling, nonregular waveguides and the waveguides containing casual dissimilarities. Process of origin of optical caustics in a near field on a back of short pieces of a multimode waveguides is interlinked either with the transient behavior of natural modes of a light pipe, or with the diffraction location effects of the plane waves localized on surface of surroundings. The important role of the caustic surfaces in wave problems is defined by that they characterize a family of optical rays and allow estimating a pattern of behavior of a field in all space of the waveguide. The wave caustics formed after short pieces of a multimode fiber have a vertical nature. Such assertion expressed by M. Berry and J. Nye in terms of catastrophe theory are the subject of the given experimental work. The caustic near its cuspidal point contains the vortices in the coupled states with the twofold topological charge. Transition of the wave caustic is accompanied by the vortex sign conversion. At the cuspidal spike the two vortices are unified in the vertical unfolding.

For the account of the propagation speed of radiation, a precision laser rangefinders based on a two-frequency opto-electronic recirculation and the phase method of measurements have been developed. A semiconductor laser diode with asymmetric quantum-well heterostructure is used as the source of radiation at two different optical wavelengths. It allows to receive information on the propagation speed of laser radiation along the line of supervision and to take into account the exact value of the radiation speed in the distance calculations.

The temperature dependence of the lasing threshold in the GaInAs-GaInAsP-InP bi-quantum-well heterolasers with different widths of the quantum wells (4 and 9 nm) has been determined. Processes of non-radiative Auger recombination which occur in the active region of the quantum-well lasers have been included into consideration. The analytical approach for the evaluation of the characteristic temperature of the lasing threshold is presented. For described asymmetric quantum-well heterostructure lasers, it is shown that the influence of Auger recombination processes on the temperature behavior of the lasing threshold is not essential until the temperature of the active region is lower than 360 K and the cavity losses do not exceed 80 cm^-1.

The paper presents an overview of semiconductor laser and detector structures for the Mid-Infrared wavelength range (3 - 5 μm). Recent progresses in new laser systems are described: intersubband InAs/AlSb quantum cascade lasers (QCLs), interband type-II "W" lasers, and interband quantum cascade lasers (ICLs). All these laser structures employing AlSb, InAs, GaSb and related alloys have the potentiality to reach the challenge of room temperature operation in continuous wave for modern applications. The description of detector structures is focused on interband transition systems based on bulk InAs_0.9Sb_0.1, type-III InAs/GaSb superlattices or InSb/GaSb quantum dots.

The high-intensity singular beam turns out to be created by means of the ordinary cover glass for a microscope. For this it is necessary to place the edge of the cover glass into the high-power fundamental laser beam. At the expense of the technical wedging of the cover glass beyond the transparent appears the high-quality singular beam bearing the optical vortex. The given paper represents the physical mechanism of such process illustrated with the vast experimental and theoretical results.

In the present paper the modified effective-index model of photonic-crystal waveguide is proved and presented. This model allows to reduce the three-dimensional numerical analysis to the two-dimensional consideration of the waveguiding due to representing of the waveguide as its step-index analog with the cladding region described by the effective refractive index of two-dimensional photonic crystal (PC) and the effective core size. The effective core size allowing equivalent description of waveguiding properties in the PC waveguide using the modified effective-index model and its numerical approximation are numerically defined. The obtained data have been used for numerical investigation of waveguide couplers formed by tapered photonic crystal fiber (PCF). It was shown that the couplers have smaller loss in comparison with couplers made by tapered step-index fiber.

Several types of switches based on optically bistable (OB) thin Fabry-Perot interferometers are reviewed. Applications for time-division multiplexing are proposed and demonstrated experimentally using both separate OB pixels and those coupled by transverse effects in arrays of various types. Compatibility with modern WDM/DWDM fiber optical networks is discussed.

Interaction of two coaxial Gaussian pulses of different frequencies simultaneously propagating in the media with cubic nonlinearity and anomalous group velocity dispersion is considered in the case of two spatial dimensions: one transverse spatial dimension and one longitudinal dimension for the propagation axis. Variational approach (the so-called average Lagrangian method) is applied to the set of two coupled nonlinear Srodinger equations with the ansatz in the form of two Gaussian pulses the same center. Different possible modes of propagation are investigated and key parameters defining their limits are found. It is shown that nonlinear interaction results in the complicated non-trivial effects in the interaction of the simultaneously propagating pulses.

A near-field structure of the semiconductor laser emission is revealed using image deconvolution of SNOM measurements. The comparison with the atomic-force microscope measurements of the emitting surface relief shows that inhomogenities of this structure are likely related to nano-scale inhomogeneities of the emitting laser surface. To retrieve the true structure of near-field laser emission taking into account the probe transfer function, the image deconvolution method based on the Tikhonov's method of generalized discrepancy was used. As a result, in the SNOM measurements small (3-4%) variations with a spatial size of about 50 nm have been discerned.

The paper addresses an analysis of the transversely varying thickness modes of a piezoelectric resonator affected by a convex anisotropic boundary surface. We show that anisotropy of the boundary surface strongly influences the frequency spectrum of eigenvibrations so that some frequencies increase whereas some others reduce. The relations to calculate the frequency spectrum and relative amplitudes of vibrations are derived. A numerical simulation is provided for the crystal resonator of SC-cut.

The automated control technique of optical fibers positioning for switching fiber-optical component manufacturing is considered. The agreed filtration as an autoconvolution of an optical field distribution, emitted by core at longitudinal illumination or focused by fiber at transversal illumination is used for fiber core axes offset determination. The autoconvolution maximum coordinates correspond to the core center double displacement concerning base coordinates. The technique mathematical thesis, results of a computer simulation modeling and experimental researches on the acting technological equipment are adduced. The offered technique is more effective than traditional methods of a filtration in frequent or space area, as requires a smaller amount of mathematical operations, does not put forward a problem of filter pulse response direct determination and ensures high accuracy parameters.

It is experimentally and theoretically shown that a vectorial topological dipole is formed in the radiation after a basic canal of a fiber-optical coupler. The dipole consists of two polarized umbilics: "star" and "lemon" or "star" and "monstar" to be a steady field structure since its total topological index is preserved as the radiation transmits through the fiber.

Conversion of singular beams in a single-axis crystal is experimentally studied. It is shown that the given system is able to generate singular beams in a wide spectral range.

Probes for a scanning near-field optical microscope on the base of a single-mode adiabatically tapered optical fiber have been fabricated by the chemical etching only. The transmission coefficient of light in this probes is 2 - 3 orders magnitude higher than that of mechanically pulled fiber probes. The probe may be used for green (λ = 0.48 - 0.55 μm), red (0.60 - 0.68 μm) and near infrared (0.78 = 1.05 μm) wavelength ranges. The reason of this effect is explained. Probe of the scanning near-field optical microscope on the base of microstrip line is proposed. Review of optical near-field microscopy, surface structure diagnostics and surface modification with nanometer resolution are observed.

In this work the theoretical study of pulse string construction of holographic gratings in photopolymeric materials with light-induced optical attenuation has been carried out. The analytical model describing spatial-temporal transformation of holographic grating field during construction process is developed. The model has a view of recurrence relation and takes into consideration light-induced changing of optical attenuation and diffusion processes. The results of numerical simulation on the base of the model are presented and include analysis of record stage, self-amplification stage and whole pulse string construction. The behavior of spatial profile and diffraction characteristics of constructed gratings are estimated with the help of numerical simulation. Fitting experiment and theoretical data has been made. The researched photopolymer was made in Institute of Organic Chemistry of the Siberian Separation of a Russian Academy of Sciences (Novosibirsk).

For registration and processing optical information signals was offered and realized opto-electronic vernier method of temporary situation definition of pulse information sequences, which used one opto-electronic recirculation generator with two optical wavelengths. On one wavelength in a recirculation mode there are information pulses, and on other wavelength-pulses of reference temporary scale. The developed method of automatic digtial-to-analog correction of scales is used. The signal-to-noise ratio in fiber-optic processing systems with avalanche photodiode was investigated.

The dipolar method associated with a non-linear time domain simulation program make up a powerful tool to analyse high Q-factor circuits like quartz crystal oscillators. After a brief remainder of the dipolar method, the paper will attempt to identify the main amplifier characteristics such as limitation mechanism, input and output impedances, etc. and to point out their influence on the amplifier dipolar impedance. The effect of the amplifier non-linearities on the oscillator characteristics, as well as the particular role of the crystal parallel capacitance are particularly emphasized.

We investigate polarization state evolution in the fundamental mode in a weakly guiding highly elliptic twisted optical fiber. On the basis of the scalar wave equation the analytical expression for the fundamental mode is obtained. Twisting-induced polarization corrections to the propagation constant are found. It is demonstrated that in some limiting case the rise of such corrections can be explained as a manifestation of topological Pancharatnam-Berry's phase.

We investigate the band-gap structure in a weakly guiding strongly anisotropic optical fiber, in which the anisotropy axis uniformly rotates in a transverse plane with z increasing. It is demonstrated that there is a gap in the spectrum of the scalar wave equation with the width proportional to the anisotropy constant.