Optical reflectivity and transmissivity measurements have been used to investigate the dynamics of melting and recrystallization of thin films of Si and Ge after laser-annealing with a ns Nd:YAG-laser pulse. We report on temperature dependent changes of the reflectivity of the liquid phase above and below the melting point and on various nucleation and solidification scenarios in thin films, depending on the energy density of the annealing laser.

Pulsed Nd⁺³ laser and 100 W cw CO₂ laser have been used to form ohmic contacts to p-Si. The contact region consists of a layered structure of Ag(5 micrometers )/Pd(300 angstroms)/Ti(1200 angstroms)/p-Si. 1 kW cw CO₂ laser was applied to obtain ohmic contacts on Au/Au-Ge:Ni/n-InP structure. Secondary Ions Mass-Spectroscopy, Electron Auger Spectroscopy and I-V dependence measurements were carried out, and these results are presented. High-quality ohmic contacts with the resistivity of 5 X 10^-5 (Omega) (DOT) cm² can be achieved using cw CO₂ laser.

A new method for the studies of the spontaneous magnetic field in quasi-2D systems such as high-temperature oxide superconductors is presented. For measuring of magnetic field was used deconfinement anyons at interplanar hopping induced by laser irradiation. Magnetometer with optical access was used for measurement of the light induced changes of magnetization at different temperature and intensity of light and external magnetic field. Observed behavior is probably the evidence of the existing of a phase with fractional statistics and spontaneous magnetic field.

Superconducting Y₁Ba₂Cu₃O₇ thin films were prepared by in-situ oxygen plasma-assisted laser deposition. It was revealed that cw CO₂ laser heating of substrate surface may be a method for reduction of particulate density. The buffer layers such as Ba(Sr)TiO₃ and YSZ(111) were successfully experimented for preparation of good superconducting thin films. A multistep superfast CO₂ laser annealing was investigated as a method of modification of the Y₁Ba₂Co₃O₇ thin films on Si. It is shown that N₂ laser ablation may be a proper technique for patterning Y₁Ba₂Cu₃O₇ thin films. The films were characterized by EDAX, SEM, XRD and Raman spectroscopy.

Electron microscopy studies are performed on steel samples submitted to high-intensity CO₂ laser irradiation. The results are analyzed in connection with the macroscopic characteristics of the laser irradiation bead as against the required performances for a quality laser welding. An appropriate description of the experimental evidence is obtained through the intermediary of a 2D numerical analysis of the cooling dynamics subsequent laser irradiation.

The high-power laser beam welding is a progressive technology which can be employed in optoelectronics and integrated optics. Its advantageous feature is the possibility to achieve a long-term stable and high mechanically reliable coupling between a semiconductor injection laser and an optical waveguide. Two proposed and investigated schemes of stable and reliable couplings of semiconductor laser to fiber-optic waveguides are described. Both schemes employ high-power impulse Nd-YAG laser beam for the fixation of the fiber-optic waveguide to the laser diode heat sink. Specially designed mechanical components are used for this purpose.

Epitaxial superconductive and ferroelectric thin films, buffer layers and multilayers were created by laser ablation deposition on monocrystalline and technological substrates. Deposition of complex multilayer systems composed of YBaCuO, YSZ, ZrO₂, CeO₂, SrTiO₃, PZT, PLZT, and PMN layers, and some properties of these systems characterized by XRD and electrical measurements are presented.

The principal experimental data are reported and the models are developed for the photodescription of alkali atoms from a surface of transparent dielectrics and for their photodetachment from own metals.

Simple single-particle iterative procedure is proposed to simulate molecular flows in capillaries. Intermolecular collisions are taken into account. Based on the computer simulation the mechanism of laser action on slip flows in capillaries is described. Some perspectives of laser gas-mixture separation in capillaries are discussed.

The interaction changes between two molecules in dimer due to excitation presence are considered. The two levels approach is used. The changes in the dynamic and in the spectroscopy of such dimers are predicted.

The possibility of a low temperature technique development including combined photochemical processes of the silicon substrate cleaning, chemical vapor deposition and post treatment of SiO₂ has been demonstrated.

We review the nonlinear optical properties and their dynamics for CuCl nanocrystallites, embedded in a borosilicate glass matrix. Because of the high exciton binding energy of this compound, elementary electronical excitations are always in the weak confinement regime. In this limit, the optical properties of the quantum dots and their dynamics are essentially described by those of the bulk material. One has to consider, however, that the lack of translational invariance modifies the selection rules of optical transitions and hinders a classification in terms of longitudinal and transverse excitons.

We have conducted an extensive experimental investigations of optical properties of porous silicon with special emphasis to their dependence upon the microstructure of the material. We present the results of direct STM observation of `quantum wires' in porous silicon and time- resolved optical spectrum of nonlinear transmittance, featuring sharp peaks which can be attributed to the saturation of the optical transition between spatially quantized levels of carriers in `quantum wires'. It was found that porous silicon is strongly nonlinear optical material with Im(chi) ⁽³) approximately equals 10^-8 esu.

Nucleous layer of amorphous silicon has been used for chemically etched porous Si preparation in solution HF:H₂O (HF:HNO₃:H₂O). This effect has been utilized to produce selective-area photoemission in porous Si with submicrometer resolution for the first time. This technique can be easily incorporated into conventional semiconductor fabrication technology.

We performed graphite vaporization by an iodine photodissociation laser and obtained C₆₀ as the first by IR laser. We obtained sufficient macroscopic amount of fullerene, which enabled us to apply solvent extraction method and UV spectrophotometry.

It has been studied the fluorescence spectra of C₆₀, embedded in porous glass matrix. When compared to the spectra of C₆₀ in solution or in other solid substrates (Al, Ag, Si), these spectra demonstrate apparent difference. From the fluorescence spectroscopy results, obtained for different pump wavelength (456.9, 488, 497.5, 514.5 nm) we got the wavelength shift dependence upon the pump light wavelength.

A new non-destructive method for visualization of free carrier accumulations in standard semiconductors wafers (VCA or scanning low-angle light scattering) is being proposed first. The method has been applied to visualize large-scale electrically active defect accumulations in a number of semiconductor crystals. It allows mapping and investigating technological semiconductor wafers, being sensitive to low concentration of free carriers in the accumulations.

The method for investigation and control of large-scale recombination-active defects in near- surface regions of semiconductor wafers is proposed. The potentialities of the technique proposed are illustrated by the example of germanium single crystals.

For the first time the total transfer of pump energy to signal wave has been registered in the optical parametric oscillator with multiple frequencies. Both cases of quadratic and cubic nonlinearities have been investigated. The influence of phase mismatches (Delta) k₃ equals k₃ - k₂ - k₁ and (Delta) k₂ equals k₂ - 2k₁ on the operation of OPO is discussed.