Here consideration is given to the influence of spherical aberrations, smooth within a beam that arise in the optical channel of laser setups on the quality of phase conjugation at stimulated Brillouin scattering (SBS). A numerical simulation of phase conjugation at SBS was conducted. It was approximated to real conditions and took into account such factors as transient processes, diffraction of radiation, 3D of the medium, reverse influence of Stokes radiation on laser radiation (SBS saturation). It has been obtained that aberration of defocusing type is dangerous from the point of view of a considerable decrease of the reflection coefficient and the phase conjugation quality both in the quasi-steady-state and substantially transient mode of SBS excitation.

Method of increasing the efficiency and quality of associative (by a fragment) data retrieval in the resulting zero reflective order of a system, composed of a thin off-axis hologram and a feedback mirror, situated in its -1-st diffractin order, is considered on the example of lensless Fourier-holograms. As a feedback mirror an adopted static phase-conjugating mirror is used based on hologram of mutally conjoined waves.

The generation dynamics of a pulse-periodical Nd:YAG laser with a three-mirror interferometer inside a loop cavity is investigated numerically. A parametrical back coupling is made by dynamics gratings in an active element inside the interferometer. An index mirror of the interferometer lets the intensity of colliding reference waves change and influence on the formation of holographic gain gratings, born in the process of four-wave mixing. The mathematical model is based on kinetic equations in the single mode and single frequency approximation in description of radiation propagation in the free space and in an active medium. Also the mathematical model includes the coupled waves equation in the description of four-wave mixing. The mathematical modeling has shown, that the investigated scheme allows to receive larger power output parameters of radiation in a regime of phase-conjugation in LiF:F₂^-, in comparison with an ordinary loop scheme. The comparative analysis of generation dynamics in an offered scheme and in the loop scheme wihtout any three-mirror interferometer showed the differentiation of mechanisms of dynamic gratings formation in Nd:YAG active mediums and defined conditions for optimal work of each schemes. The conditions for optimal work of each schemes were defined.

Stimulated Raman scattering in BaWO₄ crystal under high-energy pumping of a self-phase-conjugated LiF:F₂^- Q-switched Nd:GGG laser is investigated. The output Stokes radiation obtained has the pulse train energy of up to 2 J, the peak power of up to 1 MW, and the conversion efficiency of up to 20%.

We present a modal phase-reconstruction method for analyzing wave front aberrations of rotationally symmetric optical components in two beam shearing interferometry. The optical configuration requires only two mutually coherent off-axis plane wave fronts transmitted through or reflected by the optical component under test. Finite moire beating between the interferograms and the CCD array is used to subtract the linear carrier introduced by defocus and the tilt making the presense of high order aberrations more evident. The difference wave front is described by elliptical Zernike polynomials as a function of the amount of lateral displacement between the two aberrated wave fronts. The method allows for accurate wave front reconstruction inside the quasi-elliptical overlap area between the laterally sheared interfering beams. Results of numerical experiments and applications of the technique for measuring aberrations of simple biconvex spherical lenses are presented.

The system of a mirror with a variable focal length, controlled by pressure variations generated in a cooling medium behind the mirror plate, was developed and investigated for the high power cw CO₂ industrial laser. The mirror was tested under condition of the laser operation as inter and outer cavity mirror. The results of the experimental analysis confirm that the use of the controllable curvature mirror in the laser resonator allows the dynamic changes in the resonator configuration and corresponding modification of the lasers output characteristics. Measurements performed for the variable focal length mirror, integrated into the beam delivery system prove the possibility for the controllable dynamic adjustment of the focus position as well as the focus size in the range, which is dependent on the mirror location relatively to the focusing optics.

Diffraction microlens arrays has been fabricated in silica substrates by deep UV photolithography and wet chemical etching. The calculated kinoform profile has been approximated by multistep function and this microrelief has been transfered into the surface with wet etching through the photoresist mask. The diffraction efficiency of eight-level kinoform microlens is as high as 85%.

Beam quality control methods are important topics for laser beam users. In particular, highly controlled spatial and temporal profiles of a shot-by-shot single laser pulse are widely required for different scientific fields. We are developing a maintenance-free, highly qualified UV-laser pulse as a light source of the photo-cathode rf electron gun for the injector of a free electron laser (FEL) at SPring-8. The improvement of the UV-laser profile is essential for emittance reduction in the electrom beam from the rf gun. We planned to use a deformable mirror for spatial shaping, and a spatial light modulator (SLM) for temporal shaping at the same time. As the first test run, using a microlens array in a spatial filter, the spatila profile of the UV laser as a light source for the rf gun was improved. As a result, we obtained a minimum emittance value of 2π mm x mrad with a beam energy of 3.1 MeV, holding its charge to 0.1 nC/bunch. In the next test run, we applied a deformable mirror to automatically shape the spatial UV-laser profile with a feedback routine based on genetic algorithms. We report herein the principle and developing process of our beam quality control systems.

The calibration way of a Shack-Hartmann sensor for the absolute wave front measurement of collimated beams is represented. Nearly perfect spherical wave fronts originating from a single mode fiber were used as references. After the calibration, the uncertainty of the wave front curvature is below 0.002 m^-1 over a diameter of 6 mm for the investigated sensor with a focal length of 27 mm. The procedure of the collimated beam preparation with the ultimate flat wave front over one millimeter for an atom interferometer is demonstrated.

A new type of wave front sensor for applications in adaptive optics is presented. The main feature of the system is its possibility to be simultaneously used both as a wave front sensor for control of adaptive or multi-modular imaging telescopes and as a Fourier hyper spectral video spectrometer. The opportunity of work of such sensor, both on a special reference light source and on extended object is shown.

Multimode Deformable Mirrors allow to superpose aberration modes up to high orders. The elasticity analysis leads to consider manily Clebsch-Zernike modes that belong to a sub-class of aberration modes. Theoretical results and associated geometries are derived for some single modes that allows to find degenerated solutions leading to a minimum set of applied external forces. Interferometric results from various Active Optics experiments are presented.

The report gives the description of schematic optical diagram for two-beam interferometer based on two reflection gratings and two plane mirrors. The results of experimental investigation have been given.

It is established that imbedding of the defective layers into one-dimensional three-layered periodic structure leads to appearance new photonic band gaps, quantity and width of which are dependent on number of the periods of the structure, located between the next defective layers. It has been obtained that it is possible to achieve omnidirectional reflection from three- layered structure with introduced defects simultaneously at several closely arrange frequency regions.

In this work a theoretical study of the interaction between a light beam and an anisotropic nonlinear interferometer has been considered and methods to control the transmission of the microcavity using optical and magnetic fields have been developed. It has been demonstrated that anisotrophy of intracavity media determines the differences in transmission functions for various polarization modes and produces polarization instability. Varying spectroscopic parameters of the resonant medium and parameters of the anisotropic element, different types of intensity self-oscillations for different polarization modes can be obtained. To control the characteristics of nonlinear interferometer, it is proposed to use an additional light beam whose frequency is tuned into the absorption band from the excited level. The propagation characteristics of periodic magento-optical and dielectric multilayer films made of alternating layers of these materials having a symmetric periodicity with the center of the structure under a magnetic field is analyzed. The magnetic induction on this type of materials is temperature dependent and modifies the transmission and reflection characteristics of these structures. This kinds of structures, gives us the possibilities for an additional controlling of the characteristics of nonlinear interferometer.

We demonstrate a way of controlling planar defect modes in three-dimensional photonic crystals. Modification of the profile of the interfaces between the photonic crystals and the defect changes the boundary condition of the defect modes. This change brings about modulation of the frequency of the defect modes. A planar defect in three-dimensional photonic crystals has two interfaces between the defect and photonic crystals. They can support surface modes. When the frequency of a planar defect mode comes into the surface modes, the defect mode is assisted by the surface mode. If the frequency comes near the band edge, the defect mode couples to a standing wave at the band edge. Otherwise, the planar defect modes are not excited so effectively because reflection from photonic crystals is diffraction.

We describe the investigation of a dual laser injection seeding and switching of an optical parametric oscillator. This option is part of a differential absorption lidar (DIAL) transmitter system for measuring environmental species at two wavelengths. For instance the realization was accomplished by using an injection seeded diode pumped Nd:YAG laser as pump for an optical parametric oscillator (OPO). The purpose of these studies was an evaluation of different injection seeding techniques and their practical applicability. The suitable wavelengths were generated by injection seeding the OPO at the signal wavelength. Experiments with one and two external cavity diode lasers were performed to generate the required two idler wavelengths for the measurement. By this method line-narrowing occurs. A spectral width of the pulsed OPO of 200 MHz was achieved. Within the seeding and switching range at these two wavelengths inter-mode mixing was observed.

The main requirement of stable work of tunable lasers is the constancy of reflection coefficient for laser mirrors in the necessary spectral range. In order to synthesize and make mirrors for IR-range we elaborated multilayer film structures of two kinds. In the first case received mirrors with the special quarter-wave films - substrate design have being used for the tunable CO₂-laser in the range 9÷11 μm. In ot her case we designed and investigated mirror's multilayer structures similar to unsymmetrical Fabry-Perot interferometer's one. The really fabricated interferometer based on such mirrors had the dissolution 13±1 cm^-1 in the range 800÷1300 cm^-1.

A phase-locked loop (PLL) method application for processing the recorded spectral interferograms obtained under a partial dispersion compensation in a white-light interferometer is considered. The PLL method, which is a special simplified version of the general dynamic recurrence non-linear data processing method, has been realized in iterative m ode which provides the unwrapped phase recovery in temporal Fourier holography. The accuracy of the iterative PLL method has been investigated via the comparison of the unwrapped spectral fringe phase obtained by processing the recorded spectral interferograms with the absolute phase resulting from knowledge of both dispersion in the interferometer and the absolute distance between mirrors of the interferometer.

The results of investigations and developments of hologram and rule diffraction gratings for tunable lasers intended for autocollimation and grazing incidence of radiation are presented.

The composition and time evolution of the Stokes pulse spectram have been studied. A cell with CCl₄ was pumped with the radiation from the TEM₀₀ YAG:Nd laser with the electrooptic shutter. Its spectrum consisted of several (1-6) longitudinal modes whose number chnaged stochastically from pulse to pulse. The SBS spectrum of the laser pulse compressed from 8ns to 1.2ns consisted predominantly of one frequency or, rarely, of two to three ones. The chronography of the Fabry-Perot interference pictures of the Stokes pulse showed simultaneous excitation of these frequencies.

A method for the laser probing of an imploding plasma in the S-300 high-current generator (current of 4 MA, impedance of 0.15 Ω and current rise time of 100ns) with the use of a YAG:Nd laser diagnostic setup is described. The setup enables the five-frame probing of the plasma with an exposure of 1 ns and an interval between frames of 10ns. Stimulated Brillouin scattering in carbon tetrachloride is used to compress the laser pulse of the master oscillator. Five stages of the second harmonic generators with optic delay lines form the intervals of the probing beams. Runs of shallow photographs of the plasma of wire liners and Z-pinches have been obtained.

Temporal and modulating characteristics of a fullerene-doped nematic liquid crystal spatial light modulator based on Mg-phthalocyanine nanocrystals have been investigate. It has been established that the structure exhibits high speed and operates at supply voltage pulse frequency of more ethan 100 Hz. A mechanism of a liquid crystal mesophase orientation using a complex formation between fullerene and phthalocyanine has been discussed. Possibilities of the system for display application have been examined.

An efficient increasing of transmission line can be produced with hollow waveguide at IR range. In this paper we are discussed the current status of hollow waveguides. The hollow core structure is well suited for the transmission of high laser powers as well as for some other applications. Hollow waveguides are an attractive alternative to solid-core IR fibers. Today losses for these unique guides are as 0.1 dB/m. Optical connecting of a waveguide laser with the hollow waveguides are discussed. A theoretical model of a fiber-coupling CO₂ laser and a pigtail-type CO₂ laser with As₂S₃ optical fiber are analyzed also.

A specific nonspecular effect which should attend the partial reflectance of a light beam at a plane interference of two isotropic media is considered. The effect should take place when the incident beam carries the well-defined orbital angular momentum, it consists in such a redistribution of the electromagnetic energy inside the reflected beam that the intensity increases at one side from the plane of incidence and decreases at the other. The effect is described on the basis of the concepts of a local angle of incidence and of local reflectivity. The key points of this approach are as follows: the azimuthal variation of the phase of the incident beam stipulates the variation of the local angle of incidence across the interface, this variation, in turn, stipulates the variation of the local reflectivity and, as a consequence, the modulation of the intensity profile of the reflected beam.

The report considers composition, technical characteristics and application of complete sets of hologram optical elements "HOLOS" proposed for using in secondary and high educational institutions for educational and investigational works, mainly in the field of diffraction and laser optics. Methodical materials for laboratory works using sets "HOLOS" and laser radiation sources have been given.

Programmable diffractive optics utilizing a high-resolution liquid-crystal phase modulator is demonstrated as a technique for large-range, two-dimensional aberration control. A high-resolution phase modulator system introduces modulo-2π phase compensation via discrete-step phase modulation and operates with 307,200 independently addressable elements, and total optical efficiencies of up to 93%. Near-diffraction-limited imaging and beam directing is demonstrated in a telescope system with large off-axis aberrations. Wavelength-agile and extended spectral bandwidth operation are also demonstrated.