This PDF file contains the front matter associated with SPIE Proceedings Volume 9065, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Interaction of ultrashort laser pulse with metals is considered. Ultrafast heating in our range of absorbed fluences F_abs > 10 mJjcm² transfers matter into two-temperature (2T) state and induces expressed thermomechani­ cal response. To analyze our case, where 2T, thermomechanical, and multidimensional (formation of surface structures) effects are significant, we use density functional theory (DFT), solutions of kinetic equations in τ- approximation, 2T-hydrodynamics, and molecular dynamics simulations. We have studied transition from light absorption in a skin layer to 2T state, and from 2T stage to hydrodynamical motions. We describe (i) formation of very peculiar (superelasticity) acoustic wave irradiated from the laser heated surface layer and (ii) rich com­ plex of surface phenomena including fast melting, nucleation of seed bubbles in hydrodynamically stretched fluid, evolution of vapor-liquid mixture into very spatially extended foam, mechanical breaking of liquid membranes in foam (foam disintegration), strong surface tension oscillations driven by breaking of membranes, non-equilibrium freezing of overcooled molten metals, transition to nano-domain solid, and formation of surface nanostructures.

Two-temperature thermal conductivity coefficient κ, and electron-ion coupling parameter o: are obtained using Boltzmann kinetic equation in the relaxation time approximation. These coefficients are necessary for the quantitative description of the two-temperature state with hot electrons T_e much greater than T_i created as result of absorption of femtosecond laser pulse. Simple, noble, and transition metals are considered. An influence of d- band electrons, which play a significant role, has been evaluated for two latter groups of metals.

We demonstrate comparing two types of X-ray generation source based respectively on 10 Hz repetition rate laser pulses with using massive solid target and 1 KHz repetition rate from a thin-foil target in a rather small configuration. The variation of generation parameters such as the incidence angle of laser pulse, size of target and target materials was described and evaluated by theoretical estimations. The dependence of number K_áphotons generated by Cu and Ni targets has shown as function of the intensity laser radiation. The size of x-ray source was detected in both cases.

The laser-induced damage (LID) thresholds of pure fused silica (Corning 7980) have been measured with single temporal mode nanosecond pulses at 1064 nm. The laser beam has been focused by spherical and conical lenses into 1.6 μm diameter spots. In the case of pseudo-Bessel beam (conical lens) which inherently was not subjected to self-focusing the threshold has been close to the intrinsic threshold in fused silica. However, the measurement with pseudo-Gaussian beam (spherical lens) has shown about 30% lower value of threshold. Complete identity in the cross-section distributions of beam intensities and considerable difference in measured thresholds indicate that self-focusing influence on the LID of dielectrics even for tight focused laser beams.

Laser-induced electronic excitation, absorption and relaxation are the key issues in ultra-short laser interactions with dielectric materials. To numerically analyze these processes, a detailed non-equilibrium model is developed based on the kinetic Boltzmann equations without any appeal to the classical Drude model. The calculations are performed including all possible collisional processes. As a result, electron energy distributions are obtained allowing a better analysis of ultra-short laser interactions. A remarkable effect of the laser-field on collision frequencies is demonstrated leading to smaller free-carriers absorption than the one predicted by Drude model with a non-field dependent collision frequency. Both electron-electron and electron-phonon relaxation are then examined, and the mean energy density of the electron sub-system is investigated as a function of laser fluence and pulse duration. The developed model is useful for many laser applications including high precision in laser treatment, laser-assisted atomic probe tomography, and for the development of new powerful laser systems.

The electrostatic problem for a homogeneous axisymmetric particle is considered. The approach applied is similar to the extended boundary condition method often used in the light scattering theory. The surface integrals forming the elements of an analog of the well known T–matrix are studied in detail. The inverse problem is solved under the condition that the internal field is uniform. It is proved that this condition is satisfied for axisymmetric particles only if they are spheroids. Approximate solutions to the electrostatic problem that are based on the assumption of the uniform internal field are discussed as well.

Using open-aperture (OA) and closed-aperture (CA) Z-scan techniques, the nonlinear absorption and refraction in pure, Mg- and Zr-doped congruent LiNbO3 crystals were evaluated with cw-laser beams. The CA Z-scan technique is used for a study of the strong nonlinearities including thermo-optical and photorefractive nonlinearity in LiNbO₃ crystals. Theoretical calculations together with the measurements make possible to characterize quantitatively the thermo-optical nonlinearity and to determine the threshold dopant concentration of the photorefractive damage which is very important for nonlinear optical applications.

The paper is devoted to modeling of thin metallic film on a glass substrate oxidation under the action of ultrashort laser pulse sequence with taking into account surface and bulk oxidation and electronic excitation.

Thermography methods have found their applications in different fields of human activity. The non-destructive feature of these methods along with the additional advantage by automated remote control and tests of nuclear installations without personnel attendance in the contaminated zone are of particular interest. Laser active pyrometry and laser lock-in thermography for in situ non-destructive characterization of micrometric layers on graphite substrates from European tokamaks were under extensive experimental and theoretical studies in CEA (France). The studies were aimed to obtain layer characterization with cross-checking the layer thermal contact coefficients determined by active laser pyrometry and lock-in thermography. The experimental installation comprised a Nd-YAG pulsed repetition rate laser (1 Hz - 10 kHz repetition rate frequency, homogeneous spot) and a home-made pyrometer system based on two pyrometers for the temperature measurements in 500 - 2600 K range. For both methods, the layer characterization was provided by the best fit of the experimental results and simulations. The layer thermal contact coefficients determined by both methods were quite comparable. Though there was no gain in the measurements accuracy, lock-in measurements have proved their advantage as being much more rapid. The obtained experimental and theoretical results are presented. Some practical applications and possible improvements of the methods are discussed.

Laser ignition can yield certain advantages compared to conventional sparkplug ignition. Among other already frequently discussed reasons due to: i) option for sequential or multipoint ignition which can contribute to more reliable ignition in direct injection engines; ii) ignition of leaner mixtures at higher compression being most relevant for gas engines. A satisfying solution to the above mentioned requirements is the longitudinally diode-pumped passively Q-switched Cr⁴⁺:YAG/Nd ³⁺:YAG laser capable of emitting ∼1-ns-pulses of at least 20 mJ . This type of solid-state laser (SSL) confectioned in an engine-compatible form can be called a laser sparkplug. Early versions of this concept comprised a high-power diode pump laser (quasi-cw power <500 W @ ∼500 μs duration) which were placed remote from the engine to avoid detrimental influences of temperature, vibrations, pollution etc. In this case only the SSL is exposed to the elevated temperature in the vicinity of the cylinder walls (<100°C). Recently, technical and cost-oriented considerations allow a change of concept from fiber-based remote pumping via edge emitter arrays to the use of newly developed so-called power VCSELs with two-dimensional stacking. Collimation to form a round pump beam thereby becomes much easier. Their temperature resistance allows lower-cost direct mounting although thereby a wavelength shift is induced. The Q-switched SSL in the sparkplug also faces temperature dependent phenomena like reduction of pulse energy and efficiency, a change of pulse timing and beam profile which will be discussed in the paper.

This paper introduces quantum communication concepts to the scientists starting to work in the field of quantum optics and quantum information. Several topics are covered: (1) single and entangled photon sources; (2) quantum key distribution protocols; (3) current and future quantum communication networks; (4) experimental realization of singlephoton sources: state-of-the-art. More details on single photon generation and characterization methods are provided on the examples of the author’s results on room-temperature single-photon sources with definite linear and circular polarizations.

The stable colloid with silver nanoparticles has been produced by irradiation of metal target in deionized water by pulse 1064 nm laser. The dependences of the nanoparticle size and colloid stability on fluence, ablation time, surface conditions of the target, and thickness of the water layer have been studied. The sizes and shape of nanoparticles have been measured by dynamic light scattering and by scanning electron microscopy. It has been shown that decrease of the water layer thickness above the target surface leads to increase of the colloid stability. The proper number of treatment cycles allowed to prepare the target surface for production of the nanoparticles with average size about 34 nm obtained by statistical analysis of the scanning electron microscope images. Several methods have been used to increase the colloid stability: (1) increase of the laser fluence, (2) decrease of the water layer thickness above the target surface, (3) the treatment of the target surface by laser beam scanning. The subsequent increase of the colloid concentration by partial drying slightly enhanced the nanoparticle size. The optimized synthesis conditions and drying parameters allowed to produce the pure colloid with concentration about 0.5 g/l and stability over a month of almost spherical silver nanoparticles with typical size 45±5 nm.

Multi-function integrated optics chips consisting of a linear polarizer, phase electro-optic modulators and Y-branching power divider were fabricated in x-cut LiNbO₃ wafers with the aid of annealed proton exchange technique. Insertion losses, power transfer coefficient, splitting ratio and its spectral dependence were measured for Y-branching power dividers of different branching topologies based on channel waveguides. The parasitic spectral selectivity and photorefractive damage were suppressed by optimization of branching topology, introducing an extra taper with variable parameters.

In this paper we considered the effect of growth of sub-micron fibers on the surface of the enamel using focused beam of pulsed Yb-fiber laser in ambient conditions. There were disordered fibers growing perpendicular to the surface. Using the optical and electronic microscopy allowed to evaluate the diameter of the obtained fibers in the range from a few micrometers to tens of nanometer, and EDX analysis showed a chemical composition of the fibers. High-speed videotaping and thermal imaging of process of fibers growth made possible to clarify the nature of appearing fibers.

The study showed that organic alcohols with 1,2,3,5,6 hydroxyl groups can be used as reducing agents for laser-induced copper deposition from solutions (LCLD).Multiatomic alcohols, sorbitol, xylitol, and glycerol, are shown to be effective reducing agents for performing LCLD at glass-ceramic surfaces. High-conductivity copper tracks with good topology were synthesized.

The article presents the results of writing of high-performance fiber Bragg gratings in birefringent optical fibers with an elliptical stress cladding by a single 17 ns pulse of ArF excimer laser (193 nm). The gratings’ efficiency produced by a single pulse was up to 100%. Experimental results on visualization of these gratings are presented.

The deposition of nano-size copper particles was carried out by means of ink-jet printing on the ceramic substrate (silicon and faience) using Nd⁺³:YAG laser. Glycerin and aqueous based nano copper inks were prepared and were inkjetted in this study. The sintered copper film had a grainy structure with neck-like junctions. The microstructure and soldering properties were examined using XRD, SEM-EDX and optical microscopy. The dependence of the electrical resistance of the ink-jetted copper interconnection lines on the parameters of laser sintering regimes was estimated.

Under full temperature monitoring investigation of the melting of overhang layers has been conducted. Mechanisms of the melt penetration into loose powder bed have been determined. Also temperature regimes of the selective laser melting process of the 3D object from steel 316L powder were investigated.

By means of first principles calculations we studied the intense femtosecond-laser excitation of several boron­ nitride nanotubes and a boron-nitride doped graphene layer up to irradiation levels where these structures disintegrate. We performed molecular dynamics simulations using our in-house Code for Highly excited Valence Electron Systems (CHIVES). For different boron-nitride nanotubes we determined the damage threshold in terms of the electronic temperature and the absorbed energy per atom. We found that all nanotubes studied were destroyed in the first 200 fs after an ultrafast laser excitation heating the electrons to 108 mHa (34103 K). Some tubes also disintegrated at lower electronic temperatures. For the boron-nitride doped graphene we found that at a laser-induced electronic temperature of 100 mHa (31577 K) bonds break and the boron-nitride dimer leaves the structure.

In this paper, we discuss the issues relevant for the laser-machining process, including the precision and the material removal rate. We have investigated a surface morphology and a mass loss of technical rubber and plastic, industrial silicon and stainless steel ribbon after irradiation by microsecond laser pulses at different pulse energies, repetition rate and irradiation strategies. Laser milling with microsecond pulses (~ 10^-5-10^-6 s) is a thermal material removal process usually associated with detrimental effects such as heat affected zones, a recast layer and debris. It was shown, that process optimization can lead to considerable reduction of the above mentioned negative effects. The mass removal rates are analyzed depending on environment conditions and laser influence regimes. At the optimum operation parameters, have demonstrated that the experimental mass lost is significantly different from the theoretical estimations and this demands a future model improvement.

Laser-induced crystallization in the volume of plates of Foturan™ photosensitive glass (PG) at heat treatment under the CO₂-laser radiation on previously produced microdefects is considered. Processes of a crystal phase nucleation and growth during exposure of PG plate by CO₂-laser are investigated. Comparison of heat treatment conditions of PG plate under furnace heating and when exposed to irradiation of CO₂-laser is made.

Laser-applied thermochemical modification of thin metal films is the basement for perspective technology writing the submicron structures. Using the materials that are produce the transparent oxides layers during the heating should be perspective for to increase the resolution of this technology, but a detailed study about dependence of the oxidation process on the dynamics of the optical characteristics should be made at first. This article presents an attempt for to creation a new theoretical model, which allows showing in dynamics the process of metal film oxidation by laser pulses.

Glass-phase materials, such as glass-carbon, ceramics etc., are a wide class of substances applied in electronic industry. These materials often need special technologies for their processing. Unlike traditional methods of micromachining, focused ultrashort laser pulses of sufficiently high fluence makes it possible not only to avoid the majority of side effects, including temperature, but also to create a qualitatively new laser technology for "hard materials". When using ultrafast lasers in micromachining processes it is necessary to account the possible negative effects that occur in the processing of brittle materials. Removing material from the surface in cold ablation process caused by laser light, in such a short period of time with such a high rate, creates the area of high pressure in the interaction zone that could cause a microdamage of brittle materials. To study the stress-strain state arising in brittle materials under the influence of ultrafast lasers, the special physicalmathematical model of the process was formulated. As a measure of the mechanical action of laser radiation on the processed material in cold ablation the reactive force was taken. As a mechanical reaction of the treated glass-carbon substrate a back pressure generated by the reactive force was considered. Brittle materials suffer plastic deformation, as a rule, only in the areas of high-temperature heating. Hence, in case of picosecond treatment in cold ablation process the material, from a mechanical point of view, was seen as a perfectly elastic up to its destruction. From a geometrical point of view, the processed object was presented in the form of a thin rectangular plate, loosely founded on the elastic base.

In this report we have presented the results of forming waveguide structures in the bulk of porous glass (PG) plates soddened with water solutions of different concentrations of glycerol — substance with high polarizability under the laser irradiation of wavelength low absorbed by plate material. Chemical composition of the plate used in experiment was such: 94.73SiO₂ – 4.97 B₂O₃ – 0.30 Na₂O, with porosity δ_pg= 0.26 cm³/cm³ and average channel size 2÷4 nm. As the irradiation source the pulse fiber ytterbium laser with wavelength 1.07 um and with pulse duration ~100 ns and pulse frequency 10÷100 kHz was used. Waveguide structure forming was occurred while the PG plate was moving with velocity 2÷3 um/s relatively to the formed irradiation beam.

We presented the results of local modification of the optical properties in a bulk of photochromic plates of porous silicate glasses impregnated with silver halides, under the influence of pulsed fiber ytterbium laser. We have presented a research by optical methods of the modified areas which have an extended and the complex structure formed during laser irradiation. Such a microstructure in the amount of glass may be the basic elements of optical fiber systems for various applications.

The results of the study of the polariton mechanism of microstructuring of silicon in near-IR range during irradiation by picosecond laser pulses are presented to discussion. The experimental results of influence of laser pulses (1064 nm, 33 ps) on silicon in the dependence of laser energy, focusing conditions and number of pulses, as well as numerical modeling of conditions of excitation of the surface polaritons are presented. Low probability of surface polaritons excitation during picosecond laser irradiation is shown.

The formation of morphological structures on system SiO₂/Si by pulsed ytterbium fiber laser has been investigated. The resulting structures are investigated by atomic force microscopy. It is shown that during irradiation on surface of the monocrystalline silicon wafer covered by a thin layer of thermally grown silicon dioxide (SiO₂), there are significant structural changes associated with localization on the surface of the silicon strips of slip-lines and grid of slip-line formed by the intersection of these strips. It is also shown that exposed to laser radiation in the silicon-silicon dioxide system there are structural changes that lead to the change of the electrophysical properties of SiO₂/Si system. Changes in electrophysical properties of the oxide and the interface are more observed in the area of direct exposure to the laser beam on the silicon substrate where there are maximum structural changes of the silicon surface manifested in the form of a lattice slip lines. It is found that there are laser-induced defects in areas remote from the irradiation zone.

In this work, the formation of micro-and nanoscale periodic structures on the surface of system SiO₂/Si by nanosecond laser pulses has been investigated. Under irradiation of experimental samples with ultraviolet ArF laser pulse (193 nm) were obtained periodic wave-like structures on the surface. The dependence of the surface topology of system SiO₂/Si on the energy density of the laser pulse and the number of pulses has been studied.

In this work, we report an observation of process of local destruction monocrystalline silicon with a scanning beam irradiation of pulse ytterbium fiber laser with a wavelength λ= 1062 nm, accompanied by the oxidation of ablation microparticles. It is shown that depending on the power density of irradiation was observed a large scatter size of the microparticles. From a certain average power density is observed beginning oxidation particulate emitted from the surface of the irradiated area. By varying the parameters of the laser beam such as scanning speed, pulse repetition rate, overlap of laser spot, radiation dose can be achieved almost complete oxidation of all formed during the ablation of microparticles.

We investigate the structural changes induced in molecular layers of dicarbocyanine by single pulse laser radiation. The successive resonance excitation of all-trans isomer causes changes of the spatial orientation and relative concentration of the different molecular forms. The dependences of relative concentration on the total energy density of the photostimulation irregularly change with single pulse energy, initial concentration of the molecules the layer, and all-trans- isomer concentration (the latter is a measure of the absorbed energy for each pulse). The model of the photostimulated structural changes in cyanine layers is suggested.

Photonic properties and photoinduced transformations of hybrid materials comprising silver nanoparticles and polymethine dye layers were studied. Granular films were obtained via thermal evaporation of Ag on transparent substrates in a vacuum. Polymethine dye was spin-coated over the Ag films. The samples were characterized by optical spectroscopy, confocal fluorescent and scanning electron microscopy. Transformations of polymethine dye molecules were studied under the action of pulsed and cw laser irradiation. The threshold of laser induced transformations of dye molecules in hybrid films was found to be much lower than that for the bare dielectric substrate under the action of Nd:YAG laser second harmonic pulses. In the case of a hybrid film, transformations lead to the increased absorption in the J-aggregate band while the dye layers on a bare substrate experience, albeit 3.5 times smaller, decrease of absorption. Enhancement of absorption and fluorescence of dyes in the fields of Ag nanoparticles was observed.

The focus of this paper is to show the work experiences with laser cleaning on sculptures made of terracotta, plaster, wood and wax. These materials exhibit peculiar features that often prevent the use of traditional cleaning procedures to remove the surface dirt, soot or carbonaceous deposits and other materials coming from environment or ancient conservative interventions. To overcome the difficulties in the cleaning of the above mentioned materials, laser technology was tested. The laser irradiation and cleaning tests were carried out with a Q-switched Nd:YAG system under the following conditions: wavelength 1064 nm and 532 nm; energy 4-28 mJ; pulse duration 10 ns; spot diameter 2-8 mm; frequency 5 Hz. The irradiated surfaces were analyzed before and after the laser tests, with the aid of a video microscope and a reflectance spectrophotometer, in order to evaluate the morphology and colour changes of the surfaces. Before starting with the cleaning intervention, some diagnostic analysis was performed on the sculptures in order to obtain the identification of the original materials and of the surface deposits. Concerning this, Fourier Transform Infrared spectroscopy, X-ray fluorescence spectroscopy, and internal micro stratigraphic analysis were performed. This research demonstrated that the laser cleaning is an effective method to remove the surface deposits preserving the original patina of the sculptures and the opacity of the wax. The results gathered in this work encourage to continue the research in order to better understand the interactions between the laser beam and the surfaces and to find the most appropriate laser conditions to clean the sculptures.

Fluorescence lidar imaging can be regarded as an effective tool for early diagnostics and documentation of the outdoor cultural heritage, with the aim of a correct planning of conservation and restoration of monuments. In this paper we present the latest advancements on fluorescence hyperspectral lidar imaging recently achieved at IFAC-CNR in terms of instrumentation and novel applications. In particular, the paper focuses on the upgrading of some key technical features, such as: the scan speed of the sensor, spatial resolution at the surface and field of view of the instrument. The upgrading of these technical characteristics has also made it possible to successfully extend the applicability of the technique to the diagnostics on wall paintings, which requires an improved spatial resolution. Finally, we outline the potential of a new concept of fluorescence lidar imaging system, based on the integration of hyperspectral and fluorescence lifetime spectroscopy, which enhances the capabilities of the technique for the characterization of the materials to be investigated in cultural heritage assets.

Two innovative laser scanning prototypes have been developed at ENEA for diagnostics of large surfaces relevant to monumental cultural heritage. The first, based on amplitude modulation technique in the visible, is a trichromatic (Red /Green /Blue) imaging topologic radar (RGB-ITR) specialized to collect high resolution 3D models. After proper color calibration, it allows for hyper-realistic rendering of colored features on painted surfaces and for precise localization of irregularities. The second is a line scanning system, working either in reflectance or laser induced fluorescence mode, capable of fast 2D monochromatic images acquisition on up to 90 different spectral channels in the visible/UV range, which was developed to investigate the presence of different substances onto the painted surface. Data collected during former field campaigns on frescos by means each scanning system will be reported and discussed extracting information of interest to conservators by means of specific data processing methodologies and respective software tools. Recent results relevant to paints of the Assumption on slate and canvas by Scipione Pulzone named “il Gaetano” collected in two churches in Rome (San Silvestro al Quirinale, Bandini chapel; Santa Caterina dei Funari, Solano della Vetera Chapel) from the late XVI century are presented in order to demonstrate the increased diagnostic capabilities coming from data integration. From combination of reflectance data from both instruments, the first true remote differential colorimetry has been implemented, giving a chance to test the color quality in the future from the archived images.

Terahertz (THz) spectroscopy and imaging is a non-destructive, non-contact, non-invasive technology emerging as a tool for the analysis of cultural heritage. THz Time Domain Spectroscopy (TDS) techniques have the ability to retrieve information from different layers within a stratified sample, that enable the identification of hidden sub-layers in the case of paints and mural paintings. In this paper, we present the THz TDS2 system developed in the European Commission's 7th Framework Program project CHARISMA [grant agreement no. 228330]. Bespoke single processing algorithms; including a deconvolution algorithm can be deployed to increase the resolution and the global performance of the system. The potential and impact of this work is demonstrated through two case studies of mural paintings, where the capability to reveal the stratigraphy of the artworks is demonstrated.

The modern city facilities are often being attacked by graffiti artists, and increasingly vandals leave "tags" using paints, which compound based on acids, hydrofluoric or acetic commonly. These paints not only ink the surface, but also increase the surface roughness, and such impact can not be corrected by conventional cleaning. Thus, it was requested to develop technology that would not only clean the surface, but also to restore its structure by smoothing out irregularities and roughness formed after exposure in acid. In this work we investigated the effect of restoring the surface of the glass, spoiled by acid-based paint and then treated with CO₂-laser. During the experiments, it was found that it is real to create the single-step laser surface restoring technology.

In this work we focused on the laser removal of fungi growths and foxing stains from old paper artifacts. Irradiation tests have been carried out using Nd:YAG laser’s second harmonic and characterized through morphological analysis by means of optical microscopy and UV-VIS fluorescence, along with SEM-EDX microscopy. In addition, FTIR spectroscopy and VIS diffuse reflectance spectroscopy have provided, respectively, very useful information on chemical processes of the paper ageing and on the laser removal effectiveness. High selectivity and removal gradualness were observed in the treatment of metal-induced foxing (Fe and Pb), likely arising from the contact with metal objects. Moreover, similarly satisfactory results have been achieved for the removal of fungal colonies without inducing detectable structural damage to the cellulose fibers. The best operating conditions determined have been finally used in order to approach a practical conservation problem of an original engraving by G. B. Piranesi entitled Veduta del Ponte e Castello Sant’Angelo (18th century).

In this work laser derusting and passivation process of iron objects of conservation interest were investigated. In particular, the effects induced by laser irradiation of three lasers with different temporal emission regimes were studied, exhibiting very different behavior. Nd:YAG(1064 nm) laser systems were employed in the experiments: a Q-Switching laser with pulse duration of 8 ns, a Long Q-Switching laser with pulse duration of 120 ns and a Short Free Running pulse duration in a range of 40–120 μs. These lasers are commonly used in conservation. Lasers treatments were applied on iron samples subjected to natural weathering in outdoor conditions for about five years. Moreover some experiments were also performed on metallic parts of an original chandelier from the seventies as well as on a deeply corroded Roman sword. Results obtained reveals that longer pulse duration leads to phase changes on the rust layer and a homogeneous black-grayish coating is formed on the surface (identified as magnetite) after treatment. Whereas, QS laser pulses are capable to induce ablation of the corrosion layer exposing the pure metal underneath. Finally, LQS interaction includes deep ablation with localized micro-melting of the metal surface and partial transformation of the residual mineral areas was observed. The irradiation results were characterized through optical and BS- ESEM along with Raman spectroscopy, which allowed a clear phenomenological differentiation among the three operating regimes and provided information on their optimal exploitation in restoration of iron artifacts.

Pulmonary diseases diagnostics always occupies one of the key positions in medicine practices. A large variety of high technology methods are used today, but none of them cannot be used for early screening of pulmonary diseases. We discuss abilities of methods of IR and terahertz laser spectroscopy for noninvasive express diagnostics of pulmonary diseases on a base of analysis of absorption spectra of patient’s gas emission, in particular, exhaled air. Experience in the field of approaches to experimental data analysis and hard-ware realization of gas analyzers for medical applications is also discussed.

The objective of the investigation was to test the biocompatibility of 3D porous biopolymer matrices (tissue-cellular scaffolds), made of biocompatible and bioresorbable polymers (polycarbonate, polyetheretherketone /PEEK/, polycaprolactone), including the materials with biocompatible oxide ceramics additive (TiO₂, Al₂O₃, ZrO₂ and hydroxyapatite) of micron and nano sizes, for tissue-engineering purposes. The porous samples were prepared via a layer-by-layer SLS method. The surface microstructures and their roughness were analyzed by the optical microscopy equipped with the cell analysis software. The cellular morphology, proliferative activity and adhesion of the polymeric and ceramopolymeric matrices were the subjects for comparison. The study showed that all the tested materials posessed biocompatible properties. The experimentally estimated cell duplication speed per day turned out to be maximal for polycarbonate (0.279 duplications per day) and for PEEK + Al₂O₃ = 3:1 group (0.30 dupl/day) against 0.387 dupl/day for the reference sample and 0.270 dupl/day for the group of cells placed close to the pure titanium samples.

Possibility of nanosized carbon coatings synthesis on metal and dielectric surfaces at the result of carbon emission from different impurity amount graphite materials under millisecond pulses of Glass: Yb, Er laser. Size of particles and morphology of obtained coatings were investigated with scanning electron microscopy. It was found experimentally, that separated particles of obtained carbon coating has a size about 50-100 nm. Also Raman spectras of nanosized carbon coatings were obtained to investigate a structure. At the result of Raman spectras analysis was found, that coatings are contained of different structural units depends on graphite material impurity amount. For graphite material 99.9% products of laser evaporation are amorphous carbon nanoparticles, and for graphite material with impurity amount about 30% - graphitized nanoparticles. In this article mechanical properties, such as microhardness, of obtained coatings were estimated. It is shown that microhardness of metal surfaces and surface of substrates prepared from human tooth enamel and dentin could be increased significantly due to nanosized carbon coating. Also for tooth enamel and dentin substrates was observed an ability to increase its acid resistance and protective property of obtained coatings to the action of phosphic acid (37.5%).

We present an experimental work of a broadband amplifier centered at 1550 nm using erbium doped fiber and ytterbium doped fiber pumped at 976.8 nm. The preliminary experimental results show that the gain is practically independent of the state of polarization of the pump and the signal. We propose that the Ytterbium doped fiber could be used as an option to filter the pump power. These amplifiers are based on the telecommunications amplifiers and could have direct application in wavelength multiplexed arrangements of fiber sensors, like a fiber-optic acoustic sensor or in general, in any sensors in which a broadband source and stable light source is required.

Two innovative laser scanning prototypes have been developed at ENEA for diagnostics of large surfaces relevant to monumental cultural heritage. The first, based on amplitude modulation technique in the visible, is a trichromatic (Red /Green /Blue) imaging topologic radar (RGB-ITR) specialized to collect high resolution 3D models. After proper color calibration, it allows for hyper-realistic rendering of colored features on painted surfaces and for precise localization of irregularities. The second is a line scanning system, working either in reflectance or laser induced fluorescence mode, capable of fast 2D monochromatic images acquisition on up to 90 different spectral channels in the visible/UV range, which was developed to investigate the presence of different substances onto the painted surface. Data collected during former field campaigns on frescos by means each scanning system will be reported and discussed extracting information of interest to conservators by means of specific data processing methodologies and respective software tools. Recent results relevant to paints of the Assumption on slate and canvas by Scipione Pulzone named “il Gaetano” collected in two churches in Rome (San Silvestro al Quirinale, Bandini chapel; Santa Caterina dei Funari, Solano della Vetera Chapel) from the late XVI century are presented in order to demonstrate the increased diagnostic capabilities coming from data integration. From combination of reflectance data from both instruments, the first true remote differential colorimetry has been implemented, giving a chance to test the color quality in the future from the archived images.

Experimental investigations of the absorption of laser radiation in the optical discharge when placed in the laser cavity were conducted. A significant increase in the absorption until complete absorption was established. An optical schemes of the initiation and maintenance of the optical discharge in the cavity are proposed, which greatly extends the field of application of optical discharge in technology.