Single-electron excitation of He atoms by 30 and 50 keV He⁺ impact was investigated using anticrossing spectroscopy. The measured anticrossing spectra give evidence for the assumption that in the intermediate energy range, where the excitation cross-sections have resonance-like maxima, excitation proceeds via Paul-trap promotion. The electron to be excited gains energy by transiently riding during the collison on the saddle of the two-center potential of the (He⁺)₂ molecular core.

The lowest E1(³E⁺) Rydberg state of the CdNe and CdAr van der Waals complex has been investigated by an optical-optical double resonance. Two A0⁺(5³P₁) electronic states have been used as intermediates for probing the final E1(6³S₁) state. We have measured the bound-bound laser excitation spectra of the E1"A0⁺ transition which correspond to the first observation of the bound CdNe/CdAr complexes in the E1 state. By means of Birge-Sponer linear plot of the vN-progression we estimated the spectroscopical parameters of the potential well of the Cd(6³S₁)!Ne(2¹S₀)/Ar(3¹S₀) interaction. On the other hand, in the excitation spectrum of the E1"B1 transition we observed the characteristic nodal structure of the bound-free absorption, which can be elucidated by the Franck-Condon projection of vibrational wave-function of the B1 state onto the "hump" of the E1-state potential as it was predicted in ab initio calculation of Czuchaj and Stoll. Assuming a Morse function as an adequate approximation of the inner E1-potential well we simulated the observed bound-bound spectra and hence, we obtained additional information regarding the location of the potential well minimum (R_e). Simple energy considerations made also possible an evaluation of the height of potential barrier predicted theoretically in the potential energy curve of the E1 state.

We present angularly resolved spectra of 65 fs laser pulses at 800 nm after propagation through bulk fused silica. For the first time we report angular dependence of the spectrum after propagation in a solid sample far from resonances. Reproducible spectral and spatial effects have been observed for pulse powers several times above critical power for self-focusing.

We have performed transient multi-photon ionization experiments on small alkali clusters of different size in order to probe their wave packet dynamics, structural reorientations, charge transfers and dissociative events in different vibrationally excited electronic states including their ground state. The observed processes were highly dependent on the irradiated pulse parameters like wavelength range or its phase and amplitude; an emphasis to employ a feedback control system for generating the optimum pulse shapes. Their spectral and temporal behavior reflects interesting properties about the investigated system and the irradiated photo-chemical process. First, we present the vibrational dynamics of bound electronically excited states of alkali dimers and trimers. The scheme for observing the wave packet dynamics in the electronic ground state using stimulated Raman-pumping is shown. Since the employed pulse parameters significantly influence the efficiency of the irradiated dynamic pathways photo-induced ioniziation experiments were carried out. The controllability of 3-photon ionization pathways is investigated on the model-like systems NaK and K₂. A closed learning loop for adaptive feedback control is used to find the optimal fs pulse shape. Sinusoidal parameterizations of the spectral phase modulation are investigated in regard to the obtained optimal field. By reducing the number of parameters and thereby the complexity of the phase moduation, optimal pulse shapes can be generated that carry fingerprints of the molecule's dynamical properties. This enables to find "understandable" optimal pulse forms and offers the possiblity to gain insight into the photo-induced control process. Characteristic motions of the involved wave packets are proposed to explain the optimized dynamic dissociation pathways.

Line shapes in hot fusion plasma can refelct the existence of velocity shear in the plasma. High resolution spectroscopy is needed to differentiate between line broadening by this effect and thermal line broadening. We used this technique to study plasma rotation on the RTP tokamak and the T2R reversed field pinch. Line shifts of hydrogen revealed atom speeds of 40 km/s resp. 20 km/s. Observations of the C IV resonance lines on RTP showed a relation between changes in velocity shear and the deposition of electron cyclotron heating with respect to the location of electron thermal transport barriers as well as a poloidal roation of several km/s.

Using a laser-induced fluorescence method a detailed analysis of the profiles of the ¹¹⁴Cd326.1 nm line perturbed by all rare gases was performed which revealed departures from the ordinary Voigt profile. These departures are shown to be consistent with fits of experimental profiles to a speed-dependent asymmetric Voigt profile or asymmetric Voigt profile.

In the spectral range between 480 nm and 630 nm the Stark effect of the transitions n¹Q-2¹S, n¹Q-2¹P and n³Q-2³P(n=3÷9, Q=S, P,...) was studied using electric field up to 1500 kV/cm. For such a high field the Stark splitting becomes greater than the simple structure of the atom. Hence, anticrossings of the Stark components of the same magnetic quantum number occur. The experimental results have been compared with the theoretically determined shifts. The results of caluclations show good agreement with observation not only for low field values, but also in high fields and in case of level anticrossings.

A review of the innershell photoionization of the 3d transition elements in the region of the 3p ionization (30-70 eV) and of the 2p ionization (400-900 eV) is given. For the 3p ionization the photoelectron spectra can be described by the dominant Coulomb interaction between the 3p hole and 3d valence subshells causing a large exchange splitting between the so-called high-spin and low-spin components and the spin dependence of the sub-sequent Auger decay causing a large broadening of the low-spin components. The 2p photoelectron spectra offer a complex situation due to the different influence of the spin-orbit splitting of the 2p hole, the Coulomb interaction of the 2p hole with the 3d valence subshell and the Coulomb interaction within the 3d valence subshell itself.

Atomic or molecular collision complexes are difficult to observe, because they have typical lifetimes of the order of picoseconds. The technique of differential optical collisions can be used in different ways to serve this purpose. We discuss here the methods allowing geometric observations for typical examples involving atomic and molecular collision pairs.

The results of theoretical study of orientation, alignment and coherence effects in atomic collisions are presented. The conventional and coherence cross-sections that can be measured in collisional experiments with atomic beams are expressed via quantities dependent on the dynamics only and independent of geometry. The quantities introduced are the generalized Grawert parameters describing the collisional processes that occur in gas cell experiments (average cross-sections). The generalization of Grawert parameters allows us to obtian direct relationships between the average cross-sections and the conventional and coherence cross-sections.

Results obtained recently in the studies of electron scattering by atoms and molecules in the region of large scattering angles, up to 180° have been presented.

The plasma sources basing on electrical discharges near the surfaces of ferroelectric materials have been described. It was shown that the ferroelectric plasma sources are especially useful for investigations in the field of optical spectroscopy. They have been found to be especially useful for exciting the atoms and ions or rare earth elements.

Basic research problems in Atomic Physics with positrons (total cross sections, Ramsauer minima, positronium formation, selective ionization) and some benchmark measurements in Solid State Physics using positron annihilation (He-created nano-voids in Si, Oxygen precipitates in Si, low ε materials) are discussed.

The main trends, results and methods of the investigations in AES are reviewed. The majority of the papers were devoted to the regularities and processes in electric discharges applied as spectra excitation sources. For this task the methods of plasma diagnostics, computer simulation, Fourier analysis of the noises, fluctuation as well as the correlation methods were developed and applied in AES. Lately much attention was paid to the metrological problems in spectrochemistry and analytical chemistry. At present the methods of inductively coupled plasma mass spectroscopy are implemented.

Adiabatic potential-energy curves of the low-lying ¹Σ⁺, ³Σ⁺, ¹Π and ³Π states have been determined for the N⁵⁺+He and Si⁴⁺+He systems. An ab initio calculation method with configuration interaction by means of the MOLPRO numerical code have been employed.

Van der Waals (vdW) molecules are of current interest for several reasons. They represent a unique class of simple diatomic species with weak long-range boundary forces. Properties of small vdW clusters allow one to understand forces that hold liquids and solids together. There is an increasing interest in various branches of atomic and molecular physics in determination of potential energy (PE) curves of these objects. The studies are interesting especially in the context of a prospective application as new laser media as well as experiments with cold molecules in various types of traps. Moreover, there are exist discrepancies between theoretical ab initio calculations concerning shape of the PE curves and results of analysis of experimental data. This concerns, for example, cadmium-rare gas (CdRG) and Cd₂ systems. Therefore, there is a very strong motivation for the investigations which are presented in this short communications.

Emission spectrum of the Cd vapor excited optically with strong laser light at 326.1 nm is measured over a spectral range of (200-500) nm. Many atomic transitions involving also Rydberg states and two ionic lines originating from the lowest doublet of Cd⁺ are observed and interpreted. Several systems of bands of Cd₂ dimer exhibiting extensive vibrational structure are discovered. The systems appearing in the region (320-345) nm associated with vibronic transitions from the upper states 0_u^-(6¹S₀) and 1_u(6³S₁) are analyzed and spectroscopic constants for these states are derived for the first time.

The coherence analysis technique has been used to determine the state of polarizatitn of 228.8 nm radiation emitted by cadmium atoms excited to 5¹P₁ state by electron impact. Data have been obtained for incident electron energy of 100 eV for scattering angles in the range from 10° to 40°. Reduced Stokes parameters and electron impact coherence parameters (EICP), characterizing the state of the excited atoms immediately after the collision, have been extracted from the measurements and compared with results of relativistic distorted-wave approximation calculations. Theoretical predictions are in good qualitative agreement with experimental values.

The time dependent solution of the density matrix is analyzed for the two-color light excitation of the sodium atom for the D₁ transition. The light storage effect and the slowing down of the light are investigated in terms of the populations, the dipole moment and the Raman coherences.

Line shape calculations and measurements of the Paschen β line of hydrogen (λ=12818 Å) are reported. Measurements were performed at electron densities of the plasma between 10¹⁵ cm^-3 and 10¹⁶ cm^-3. A wall-stabilized arc operated at atmospheric pressure in a helium-hydrogen gas mixture was applied as the excitation source. The radiation of the plasma, originating from nearly homogeneous plasma layers, in the end-on direction, was analyzed. A grating spectrometer equipped with a CCD detector was used for the radiation detection. The measured line profiles are compared with results of available experimental and theoretical Stark broadening data e.g. based on simulation techniques, applied also in our calculations.

To study the usefulness of second-order Moller-Plesset (MP2) correlation energies for ground states of closed-shell atoms (referred to as MP2/CA energies) in estimations of the total correlation energies of larger closed-shell atoms, we have considered atoms and ions containing from 10 to 86 electrons. First, it is demonstrated that for N-electron systems, 10≤N≤18, the MP2/CA energies provide very good approximations to the very accurate estimates of atomic correlation energies by Chakravorty and Davidson. Next, for systems with 10≤N≤54 comparisons are made with the semiempirical energies obtained when using the models by Charkravorty and Clementi as well as by Clementi and Corongiu. Finally, for atoms with 10≤N≤86 the MP2/CA energies are employed for comparison with DFT energies recently obtained by Andrae et al. The MP2/CA results have proven to provide reasonable estimates to the total correlation energies in all the cases considered.

In the previous paper steric effects in the chemiluminescence reactions of metastable calcium atoms with isomeric propyl halide have been studied. Substantial differences in the CaCl(B²Σ)/CaCl(A²Π) branching ratio were found with isomeric variation of the targets. This has been a motivation for research presented in this work. Reactions of metastable calcium atoms in the metastable ³P_J states with all commercially available normal and branched alkyl halides were studied in a beam-gas arrangement. Chemiluminescence spectra of alkaline earth monohalides were observed for calcium reactions. Total collision and chemiluminescence cross sections were measured.

A new method of retrieving of the aerosol size distribution from the signals of a multiwavelength lidar is presented. The method allows to reconstruct the distribution without assuming the lidar ratio. The method was tested on artifical data. A good agreement with the assumed distribution was shown.

Excitation energy transfer between laurdan and octadecyl rhodamine B in glycerol has been studied. The value of spectral overlap integral JDA(ν) was determined for different temperatures.

The paper presents the general model describing the absorption and emission phenomenon of the fluorescent probe molecules showing the local excited and charge transfer electronic state. We reveal the complex character of inhomogeneous broadening of the charge transfer band in solutions, where, at least, three major mechanisms are responsible for this phenomenon. The distribution of molecules describing relative orientations of the twisting moiety in respect to the basic plane of the molecule is one of the important factors, contribution to the spectral displays. It is shown that this distribution depends on the space structure of the molecule as well as on the excitation wavelength. These factors create an opportunity to appear various red edge effects at proper conditions in a solution. As an example for such modeling the experimental data obtained for laurdan probe molecules in glycerol are used.

The maximum-likelihood estimation method is considered. It is based on three-level Dehmelt scheme of isolated quantum system and it makes use of the theory of Markov-modulated Poison process. This method is applied to the analysis of the photon-counting distribution resulting from a single molecule fluorescence experiment. It is assumed that the data available for the estimation contain only the number of collected photons per time interval.

Mid-IR absorption and Raman scattering measurements were carried out for ferroelectric ceramics with composition of Ba(Ti_1-xZr_x)O₃. The main aim of presented research was to analyze the ability of these complementary optical methods to estimate the efficiency of manufacturing process as well as to investigate the molecular strcuture of synthesized material. Task is very difficult, because of sophisticated structure of presented materials as well as technology of their manufacturing. Moreover, at the room temperature, the influence of difference in crystal phases as well as existence of remnants of oxides introduces significant changes to the spectrum. Results of presented research suggests that the efficiency of atom substitution can be investigated by means of optical spectroscopy.

Optical (VIS photoluminescence, photoluminescence decay, IR absorption) measurements on Czochralski-grown silicon, subjected to several thermal treatments are presented. These data are supplemented by positron annihiliation techniques (lifetime Doppler broadening). We report also some preliminary positron-annihilation data on these films of Si-related, low-ε materials.

Set-up for positron-molecule scattering measurements in the range of energy 0.1-20 eV is presented. To obtain a positron beam with suitable electron optical parameters apparatus uses brightness enhancement stage.

The application of a reflectometric method for determining ionic concentration in water using dry test is presented. The shape of reflectance spectum of dry tests changes in proportion to ionic concentration. A portable optical reader for acquisition of these spectra was developed to assure consistency and repeatability of measurements. A portable computer controls the process of measurement and calculates ionic concentration from the acquired spectrum.

Recent studies about non-contact temperature measurement concern passive multiband radiometric systems. These systems give a potential possibility of accurate temperature measurements in case of unknown and wavelength depended emissivity of the examined object. Modeling of such systems, what is usually the first stage of system designing, requires acceptance of several simplifications and approximations. In this paper an experimental verification of modeling result is performed. Based on developed experimental setup some tests are performed. It allows us to determine some systems parameters and whole system estimation.

White-light interfermetry, also referred to as low-coherence interferometry, is an interferometric technique employing broadband light sources in order to make absolute, high-resolution measurements of several physical quantities, such as position, displacement, temperature and pressure. In the paper a model of a low-coherence interferometric temperature sensor using a Fabry-Perot sensing interferometer is presented and optimization of the sensor is discussed. The sensor uses an inexpensive source such as LED or VCSEL, standard telecommunication fibers and components, which makes it a potentially low-cost solution.

The main topic of this work is the development and optimization of a new measurement method used for in-situ thickness monitoring of thin films grown using plasma. Because of their inherent limitations, measurements methods described in literature cannot be used during the low-temperature plasma processes as they are sensitive to optical noise generated by plasma and the substrate heater. To address this problem, a new method, based on chromatic sensor, has been developed. The monitored film is illuminated by polychromatic light which interferes in it, is reflected from it and collected by three detectors with spectral responsivities coincided with human eye. Based on signals from these detectors and known relationship between the spectrum of the reflected light and the thickness of the film, it is possible to monitor the thickness of the film in real time.

For a few years, the Institute of Applied Optics have been conducting research leading to the development of GRIN lenses made of phosphate glass. Such lenses were obtained with the use of diffusion of sodium and lithium ions into phosphase glass including the silver ions, but the diameter of lenses was limited to few millimeters. Refractive index of lenses of 3-7 mm dia is expanded to the fourther exponent of the radius.

Relative abundances of positively ionized water clusters formed in a low-pressure electrical discharge as function of reduced electric field were obtained by using drift cell and quadrupole mass spectrometer. It was noticed that some clusters say with n=4 were more abundant than others, at comparable drift conditions. Dissociation energies have been derived form equilibrium conditions for relative clusters abundances. The Hartree-Fock method in 6-311G** molecular-basis set has been applied to calculations of binding energies for different structural "families" of clusters.

Results of measurements of the ratio of transverse (D_T/μ) and longitudinal (D_L/μ) diffusion coefficients to mobility and drift velocity (W) as function of reduced electrical field (E/N) for electrons in nitrous oxide are presented. The coefficients D_T/μ and D_L/μ have been determined by applying the Townsend-Huxley method. The drift velocities were obtained by using the Bradbury-Nielsen technique. A set of total and partial cross sections has been used to calculate numerically the D_T/μ and W.

Raman spectorscopy was applied to study the reactions between amine and epoxy groups, which had been expected to proceed during synthesis of hybrid polymer based on three monomers: 3-aminopropyltrimethoxysilane, 3-glycidyloxypropyl-trimethoxysilane and methacryloxy-propyltrimethoxysilane. Efficiency of the investigated reaction determines the molecular structure of the organic network and consequently - mechanical and optical properties of manufactured material. An optical system developed for the real-time Raman monitoring was connected with typical glass reaction vessel and non-invasive measurements were made. Additional FT-Raman investigation was carried out to confirm obtained results. Transformation of primary amine as well as epoxy ring opening was confirmed and role of catalyzers was discussed.