This PDF file contains the front matter associated with SPIE Proceedings Volume 6598, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

The purpose of this study was to summarize our experiences in clinical application of Nd:YAG, Ho:YAG and Er:YAG in otolaryngology- head and neck surgery. Choosing the laser type and parameters for the particular procedures was based on our previous research on tissue effects of those lasers. During the period of 1993-2006 we performed 3988 surgical procedures with the Nd:YAG laser. Over 87% of those were made for the nasal cavity pathologies as polyps, hyperplasia of inferior nasal turbinate, granulation tissue, postoperative adhesions, vascular malformations, under the local anesthesia conditions. In our experience Nd:YAG laser gives the possibility of good clinical control and low risk of side effects for disorders of high recurrence and frequent interventions necessity, as nasal polyps or respiratory papillomatosis. Nd:YAG assisted uvulopalatoplasty gives an interesting alternative for surgical procedures for snoring and slight/mild OSA-recognized patients. Due to its good hemostatic properties, it is a perfect tool for removal of the chemodectoma from meddle ear. During the period of 1995-2006 we performed 229 surgical procedures with the Ho:YAG laser, mostly for larynx pathologies (adhesion and scar tissue removal). In our experience Ho:YAG laser can serve as a precise laser knife for both soft and bony tissue. The ER:YAG laser still remain under clinical trial. Since 2001 year we performed 24 procedures of removing stone deposits from salivary glands. We believe it may become a promising method to cope with sialolithiasis which allows for glandule function preservation. All of the laser types mentioned above, can be easily coupled with endoscopes, what makes them available for all of the head and necklocalized disorders.

Photodynamic Therapy (PDT) requires three components: a dye applied as the photosensitizer, a source of light, and a possibly large amount of oxygen dissolved in the tissue. The considerably higher absorption of porphyrin photosensitizers by tumorous tissues allows the application of these photosensitizers in the diagnosis and therapy of tumors. The cytotoxic and cytolethal effects of the photodynamic therapy are associated with the formation of a singlet oxygen or production of radical species by the porphyrin photosensitizers. In the cell, the singlet oxygen or radical species impair important macromolecules like membrane phospholipids, structural proteins, enzymes, and DNA. This study describes the photodynamic effect of the PP(AA)₂Arg₂ group photosensitizers on the activity of adenosine deaminase, DNA-ase and trypsin in relation to the photosensitizer dose and the excitation energy.

Authors described one of diagnostic method in oncology Photodynamic Therapy (PDT) to recognizing head and neck cancer. They used own, modified way to inserting the photosensitizer in cancer cells. The aim of this report was presentation some patients who were suspected cancer disease of laryngeal organs on based of PDT and biopsy. The comparison of these results confirmed efficacy of PDT as diagnostic method.

The goal of the paper is to compare the results of frenuloplasty performed by means of the conventional surgical procedure and using the CO₂ laser.

The article presents the evaluation of the number of oxygenic and anaerobic bacteria in post extraction wounds subsequent to low-level laser therapy.

Titanium nitride (TiN) is regarded as a potential biomaterial for blood-contact applications. TiN thin films were fabricated by pulsed laser deposition with the Nd:YAG laser on biologically applied polyurethane. Transmission electron microscopy (TEM) study of 350 nm thick films revealed columnar structure. Such films were observed to be brittle. In order to improve the coatings elasticity, the thickness was reduced to 50nm, which limited the deposition mechanism operation to the early stage. A biological test showed that TiN surface film produced on polyurethane is characterized by good biocompatibility and decreased surface affinity for cell adhesion. The physical explanation of TEM images was based on the performed finite element calculations of the temperature and stress distribution using the ADINA program. Boron nitride thin layers were produced by means of the pulsed laser deposition technique from hexagonal boron nitride target. Two types of laser i.e. Nd:YAG with Q-switch as well as KrF coupled with RF generator were used. Influence of deposition parameters on surface morphology, phase composition as well as mechanical properties is discussed. There are an increasing number of applications in tribology where the properties of a single material are not sufficient. One way to surmount this problem is to use a multilayer coating. Application of metallic interlayers improves adhesion of nitride hard layer in multilayer systems. Tribological coatings consisted of 4, 8 and 32 layers of Cr/CrN and Ti/TiN types were fabricated with the PLD technique. It is found in transmission electron examinations on thin foils prepared from cross-section that both nitride-based multilayer structures studied are characterized by small columnar crystallite sizes and high defect density, what might raise their hardness but compromise coating adhesion. The intermediate metallic layers contained larger sized and less defective columnar structure compared to the nitride layers, which should improve the coatings toughness. Switching from single layer to multi-layer metal/nitride composition improved resistance to delamination.

Thin films of CeO₂ doped with Cu or Nd and Bi₂O₃ doped with Y were elaborated by Pulsed Laser Deposition technique from sintered Cu-CeO₂, Nd-CeO₂ and Bi₂O₃ or Y- Bi₂O₃ targets. Two types of laser ablation equipment have been applied: one worked with a KrF excimer and second with an Q-switched Nd:YAG. The films were deposited on (100) and (110) oriented Si substrates. Scanning and transmission electron microscopy, as well as, x-ray diffraction analyses showed correlation between a copper and neodymium atom fractions and crystalline structure of the (Cu, Ce)O₂ and (Nd, Ce)O₂ thin films. As demonstrated by x-ray diffraction analysis, with increased quantity of Cu, and Nd the both types of doped CeO₂ thin films manufactured by laser ablation show a change of the crystal growth preferential orientation (c-axis- orientation) from strong <111> to a strong <200> ones. In case of pure bismuth oxide deposition, both TEM and X-ray examinations revealed that at applied experimental conditions only &agr; - Bi₂O₃ (not &dgr; - Bi₂O₃) crystals were formed during ablation process. Microstructural TEM examinations permitted to show high grain refinement in Y- Bi₂O₃ thin films. Preliminary measurements show also high level of electrical conductivity in case of this oxide. Due to SiO₂ amorphous layer present at the surface of Si substrate, its crystallographic orientation doesn't influence the thin film structure of all analyzed oxides.

Controlled melting of ceramic coatings caused the need to determine the influence of laser beam power density and scanning rate within the melting depth of the coating. Applying numerical simulation method it was possible to elaborate the model of heat exchange process for three layer plate of finite thickness with deposited ceramic coating. Heat energy of laser beam moving with constant rate acted on that plate.

In this paper the results of the investigations of Al-Cu-Fe surface layers deposited by PLD technique are presented. The study was carried using different parameters of process. The morphology and chemical composition of obtained surface layers was examined. In the frames of the investigations the oxidation resistance tests of the Al-Cu-Fe layers was performed. The results indicate that it is possible to apply obtained layers as oxidation barrier.

Hydroxyapatite layers (Ca₁₀(PO₄)6(OH)₂) were deposited by means of laser ablation method using an ArF excimer laser (193 nm). The influence of substrate temperature on the structure of deposited layers was studied. The layers were deposited on Ti6Al4V titanium alloy which temperature varied from 250 °C to 700 °C. The characteristics of the hydroxyapatite coatings were determined by means of Fourier Transform Infrared spectroscopy (FTIR). The obtained spectra reveal that the presence and abundance of the PO₄ absorption bands depend on the substrate temperature. The topography of the deposited layers were analyzed with the use of an Atomic Force Microscope.

The paper describes the laser cladding of hypereutectic Al-Si alloy with chromium. An impulse Nd:YAG laser was employed for laser cladding process. The article presents the changes of microstructure, chemical composition, microhardness of the obtained clad layers, which were depended on the effect of the laser processing parameters and the thickness of chromium coatings. The laser cladding produced the very fine microstructure and higher hardness of clad layers.

The general objective of the work was formation of highly wear resistant metal matrix composite (MMC) surface layers on aluminium based Al 6061 alloy by means of laser dispersing. The surface of the substrate is locally melted by the high power diode laser beam and simultaneously powder particles are injected into molten material. The optimal process parameter window for the laser dispersing of SiC in Al 6061 has been found. The measured values of the wear rates of the sample with dispersed SiC particles are about seven times lower than that of the reference Al-substrates. Results show that laser dispersing is highly promising technology to improve the surface, mainly wear properties of light metals. However the possibilities of industrial application are still limited due to considerable laser beam power and preheating temperature applied as well low productivity because of low scanning speed, and therefore further investigations are required.

The time dependent temperature and strain-stress fields are numerically calculated for the laser cladding of protective stellite SF6 coatings on the X10Cr13 chromium steel. The temperature dependent material properties and also effects of the base preheating and time delay between cladding of the consecutive layers are taken into account. Results of the model calculations indicate that the micro-cracking susceptibility of the coating is smaller for the preheated base. In the case of the substrate initial temperature of 600 °C the calculated strain stresses lie below the limit of the stellite tensile strength. This is confirmed in experiment by the crack-free coatings while for the samples cladded on the non-preheated substrate cracks are produced. An increase of the cracking susceptibility with prolonged time delay between preparation cycles of the consecutive layers is evidenced by modelling, which agrees with experiment, too.

This paper presents results of SEM, microhardness, residual stress (measured using Weissman-Philips method) and abrasion resistance examination of a surface layer of the tools steels remelted with a laser beam. Laser remelting of the tool steels provides strengthening an increase of the surface layer as a result of formation of highly refined, nonequilibrium products of the austenite transformation. There is obtained an increase of microhardness and abrasion resistance of the surface layer in relation to traditionally heat treated steels. The influence of the tempering temperature after a laser hardening on the distribution and the residual stresses values was also examined. The values of the stresses decrease with the distance from the surface treated. Tempering steels after a laser treatment led to decreased values of the residual stresses by about 30 to 50 MPa.

Results on micro- and nanoprocessing of organic polymers using X-rays and extreme ultraviolet (EUV) generated from laser-plasma radiation sources are presented in the paper. The sources used in the studies are based on the gas puff target approach developed at the Institute of Optoelectronics, Warsaw. Processing of polymers is connected with non-thermal ablation under the influence of energetic photons of X-ray and EUV radiation. The process can be useful for practical applications as it makes possible to produce structures with sub-micron spatial resolution that is not possible using the thermal ablation. The new technology will be used for production of photonic microstructures and for modification of polymer surfaces for biomedical applications.

This paper presents a physical model characterizing the geometry of gas-assisted laser cutting of the AlSi-alloy/SiCp composite. In the model, a lot of relevant parameters that describe the inhomogeneous optical and thermophysical properties of AlSi-alloy/SiC_p have been used. Numerical evaluations of this model give some explanations of "double slope" formation mechanism during laser cutting of the AlSi-alloy/SiC_p. The theoretical results are compared with experimental data. It is found that increasing laser beam scanning speed increases the slope of cutting front.

The increasing demands for miniaturization and better functionality of electronic components and devices have a significant effect on the requirements facing the printed circuit board (PCB) industry. PCB manufactures are driving for producing high density interconnect (HDI) boards at significantly reduced cost and reduced implementation time. The interconnection complexity of the PCB is still growing and today calls for 50/50 &mgr;m or 25/25 &mgr;m technology are real. Existing technologies are unable to offer acceptable solution. Recently the Laser Direct Imaging (LDI) technology is considered as an answer for these challenges. LDI is a process of imaging electric circuits directly on PCB without the use of a phototool or mask. The exposure of the photo-sensitive resist is carried out using a laser beam that is scanned across photoresist surface and switched on and off by means of a computer control system according to the electrical circuit pattern. Usually the laser used in the LDI generates a UV line, which is suitable to the commonly available photoresists. Our laboratory system for Laser Direct Imaging is designed for tracks and spaces on PCB with minimum width distance of 50/50 &mgr;m. In comparison with conventional photolithography method, this technology is much better for 50/50 &mgr;m track and spaces. In our research we used photoresist with resolution 50 &mgr;m, but in case of using laser photoresists with better resolution (e.g. 25 &mgr;m) it will be possible to image tracks in super-fine-line technology (25/25 &mgr;m). The comparison between two technology of creating mosaic pattern tracks on PCB proved that laser imaging is promising technology in high density interconnects patterns, which are widely use in multilayered PCB and similar applications.

Systems for laser micromachining of the materials are very popular around the world. Unfortunately, this technology is not used widely in Poland. This is a result of very high prices of systems for laser micromachining, which Polish electronic manufacturers can not afford for. This article is focused on Polish proposition of the system for laser micromachining, which is adapted to producing metal stencils used in PCB manufacturing. Metal stencils are used during one of the PCB manufacturing steps. It allows to precisely position soldering paste on PCB laminate exactly on soldering places.

In the paper the authors present results about research dealing with deformations of low-carbon samples influenced by a stagnant or not moving CO₂ laser impulse. Permanent and non-permanent deformations were analysed for two cases: for constant power and for constant maximal surface temperature. Laser-based forming methods known till now, use moving laser beams. As a results of the paper it is found, that in case of constant power (for each experimental points) non-permanent (temporary) deformation decreases with pulse duration and permanent (residual) deformation is maximal for some pulse duration. But in case when surface temperature is kept constant, non-permanent deformation is constant with pulse duration and curvature of permanent deformation can be positive negative or kept zero. Aim of the research is to show possibility of laser forming by a not moving laser beam with suitable power and pulse duration with control of sample residual curvature.

In order to obtain a properly laser beam hardened track, it is necessary to make a careful selection of scanning parameters. The paper gives an initial analysis of the impact of surface temperature and scanning velocity on the hardened track width. The experiment involved laser beam hardening of flat carbon steel specimens.

Analytical modelling of thermal bending of plates by use of a laser beam with circular cross-section is presented. The most important parameters in this process have been found: the pick surface temperature and the Fourier number, which are the similarity numbers. Experimental verification was performed. Temperature distribution in the plastified layer of the material (where the material losses its elastic properties) was taken into considerations. Developed model proves that effective bending occurs when the material surface temperature is close to the melting temperature. Restrain rigidity coefficient of heated material in Presented model can be applied in various laser processing technologies, for instance in welding, cutting, surface treatment, including hardening and others. Theoretical results of residual stresses distribution in plates after laser beam pass is presented. Analysis of the solution proves possibility control of surface stress on both sides of the bent plates by change Fourier number and surface temperature.

Profiles of joints resulting from deep penetration laser beam welding of a flat workpiece of carbon steel were computed. A semi-analytical conduction model solved with Green's function method was used in computations. In the model, the moving heat source was attenuated exponentially in accordance with Beer-Lambert law. Computational results were compared with those in the experiment.

The paper presents selected laser systems used for remote detection of contamination and pollution of atmosphere. Having in view a way of taking samples for analysis, the methods used for atmosphere monitoring can be divided into two groups: sampling at the place of existing pollution and remote detection, identification, and measurement of concentration. "Stand-off" and "remote" systems of atmosphere monitoring are described here. The "stand-off" systems provide detection of pollution (gas, aerosol, smoke, dust) at long distances, without the contact with a contaminated area. These systems are active laser systems (lidars) or passive thermal systems with narrow filters matched to the bands of gas absorption and imaging the transmission changes of radiation absorbed along the path of gas presence. A single "stand-off" station can cover significant area, the size of which depends on the range of sampling radiation, field of view, and scanning speed. "Remote" systems employ various types of small point sensors and the data from these sensors are transmitted by wire or wireless connections to alarm centres. It should be pointed out that in this case, a contact between sensor and analysed area is necessary and remote detection is performed by the transmission systems of measurement data. The paper presents construction, principle of operation, and basic analytical characteristics of the chosen "standoff" and "remote" measuring systems developed at Military University of Technology, devoted to continuous monitoring of contaminations and pollution of atmosphere.

The paper presents a construction of an absorption instrument for measuring the flue gas smokiness. The instrument, which was tested in industrial conditions, is a probe of the diameter 51 mm and length 2000 mm inserted into the exhaust duct. A laser diode GaAs of the power 5 mW were used as a light source. The industrial testing was performed on Power Unit no. 10 in the power plant TUROW II in Turoszow.

The paper proposes of a new chemical analysis technique that employs the phenomenon of directional scattering of polarized light by the particles of solutions and suspensions. Laboratory tests carried out have demonstrated the existence of a dependence of the scattering indicatrix on the type and concentration of the dissolved substance. To any solution, a several hundred-element space of states can be assigned, in which each of the solutions takes on from several tens to several hundred different values. The process of laser light scattering in solutions is also dependent on the interaction of external magnetic and electric fields and on the wavelength of the laser beam and the way of its modulation. This provides an opportunity for the further expansion of the size of the space of states. As a result, a new research tool will obtained, which will constitute a complement of the optoelectronic techniques used for far in chemical analysis.

Paper presents selected issues on laser systems for detection and location of underwater objects. Specific influencing factors, as hydro-meteorological as well as environmental conditions, are also discussed. For the assumed parameters of proposed laser rangefinder model, on the basis of additional experimental results, an analysis and numerical calculations of background noise power, signal power and signal to noise ratio at the output of receiver have been performed. Thereby, the effective detection ranges of underwater objects under various meteorological conditions in different seasons have been obtained.

In the paper the authors present a laser warning receiver in air version for helicopter. Its parameters, block diagram and operation mode are described.

A content measurement of chosen ingredients in a gas mixture can be done with optical methods, e.g. using optical fibres. Their undoubted advantages are lack of disturbance of a medium to be measured and possibility of application in aggressive media. In the article, experiments have been described, aimed at developing a cheap CO-analyser, that would be based on a modified correlation method. Such an analyser could be utilized in content measurement of carbon monoxide in near-wall layer of power boiler. It could be treated as a pointer of corrosion thread in a power boilers.

Application of Laser Induced Breakdown Spectroscopy (LIBS) for investigation of chemical constitution and stratigraphy of artworks, museum objects and metallic objects with multilayer structures is described in the paper. Physical phenomena accompanying LIBS investigations are briefly discussed. Operational characteristics of experimental equipment are presented. Experimental results of measurements of various objects like paintings, sculptures, minerals, and metallic objects are shown. The State Committee for Scientific Research decision No. 120/E- 410/SPB/COST/T-11/DWM726/2003-2005 supported this work.

Air contaminants which emerge during laser ablation often cause health risks if released in the workplace and decrease laser cleaning efficiency if redeposited at the material surface. In addition, ultra-fine particles are generated if short laser pulses are applied. Consequently, a description of the nano and microparticle aerosol generation and the influence of the laser parameters, such as fluence and pulse energy, and type of material surface on the particle size distribution is given in the presented paper. The conducted experiments have shown that for applied laser fluences almost 80% of all emitted particles are in the nanoparticle size range of 30 - 100 nm. The high respirability of such particles can pose health risks, so suitable capture systems near to the processing zone or personal protective equipment such as respiratory masks are required.

The Particle Image Velocimetry (PIV) technique for measuring of velocity flow fields was presented. The PIV measurement principle was described together with experimental techniques used for both 2D and 3D PIV. The application of PIV method in a hydrodynamic tunnel, towing tank, non-thermal plasma reactors and ESP were discussed.

Brillouin spectroscopy has been applied to study a synthetic polymer and its solutions in polar and nonpolar solvents. Of particular interest has been the effect of concentration, temperature and polarity of the solvent on the mechanical properties of the mixtures studied. The experimental methods applied permitted investigation of the structural relaxation process related to the dynamics of changes in the internal structure of the polymer chains. It has been shown that the quantitative analysis of the relaxation process can be made in terms of the model based on the theory of viscoelasticity of liquids. The association processes in the systems studied have been analysed assuming the Natta-Baccaredda model. The model has been shown to be successfully applicable for description of mixtures of the polymers interacting with solvents. The limitations of the model in the situation when one of the components of the solution is neutral, while the other one undergoes strong self-association, has been considered.

In this paper, results of Particle Image Velocimetry (PIV) measurements of the flow velocity field in an electrostatic precipitator (ESP) are presented. The ESP was an acrylic parallelepiped with a wire discharge electrode and two plate collecting electrodes placed on the top and bottom of the ESP. The measurements were carried out for various dust densities. The obtained results showed that the general shape of the flow patterns at different dust densities is similar in the bulk of the flow. However, the flow velocities and level of turbulences strongly depends on the dust density, in particular in the downstream region of the ESP, behind the wire electrode.

Investigations of laser ablation plume aimed at applications for the SiO nano-film deposition are reported. The plasma formation and propagation through experimental chamber was investigated by means of Langmuir probe. The effects related to plume splitting and acceleration are discussed.

The interferometric method for ferrule geometrical parameters measuring and testing is presented. The geometrical parameters are defined according to the IEC international standards. The quality of the ferrule face has important influence on transmission parameters of optical connectors like the attenuation and reflectance.The measurements results of the spherical height for FC-APC, SC-APC and E2000-APC are presented in this work. The high value of protrusion has influence on thermal and mechanical resistance of optical connectors. The problem is presented for the temperature and vibration tests.

In this paper the authors present an example of optical transmission system based on soliton technology. Implementation of wavelength division multiplexing enables achievement of 40 Gbps in one channel. In described example a multipointmultipoint topology was applied and there the programmable WSXC optical cross connect was used. Model of such system was implemented in OptSim simulation software (ARTIS Software Corporation)⁹. Finally an error-free soliton transmission was obtained on haul from 1300 to 1800 km.

Modern optical transmission systems require both high-bit rate and long distances. Solitons are considered to be the best solution to the dispersive problem, as they preserve their shape over long distances. There are two types of solitons (PAS, DMS), which have application in optical transmission systems. In both fiber optic amplifiers are used, but DMS additionally uses dispersion management technique to achieve nearly unlimited propagation distances. Soliton WDM has many advantages, which make it attractive as far as data transmission is concerned. Some features of the transmission have been analyzed in the OptSim simulation software (ARTIS Software Corporation)⁵.