http://www.hindawi.comThe latest articles from Hindawi Publishing Corporation© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/170632Laser-induced backside wet etching (LIBWE) allows the high-quality etching of transparent materials for micro- and nanopatterning. Recent own results of LIBWE with hydrocarbon and metallic absorbers (H- and M-LIBWE) are summarized and compared with selected results of other groups regarding the etching process and the etched surface. Significant results on the impact of the liquid absorber, the material and the wavelength, and the pulse length of the laser to the etching are selected for this comparison. The etching of submicron-sized periodic structures in sapphire and fused silica with interference techniques and the selection of the preferred method in dependence on the material and the processing goal discussed. The experimental results are discussed on a thermal model considering both interface and volume absorption of the laser beam. These results have the conclusion that the etching at M-LIBWE is mainly due to material melting and evaporation whereas at H-LIBWE, a modified near-surface region with a very high absorption is ablated.K. Zimmer and R. Böhme© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/976205Thermal load as well as its three-dimensional (3D) spatial distribution has been estimated inside representative materials: glass (low thermal diffusion), silicon (semimetal properties), and sapphire (a crystalline dielectric of a high thermal conductivity) for typical laser processing and direct laser writing applications. The 3D temperature distribution allows to calculate thermal stress around the focal region. This provides an assessment tool for optimization of laser microprocessing conditions for controlled laser dicing and cutting applications.Martynas Beresna, Titas Gertus, Rolandas Tomašiūnas, Hiroaki Misawa, and Saulius Juodkazis© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/493059Two-photon polymerization of photosensitive materials has emerged as a very promising technique for the fabrication of photonic crystals and devices. We present our investigations into the structuring by two-photon polymerization of a new class of photosensitive sol-gel composites exhibiting ultra-low shrinkage. We particularly focus on two composites, the first containing a zirconium alkoxide and the second a nonlinear optical chromophore. The three-dimensional photonic crystal structures fabricated using these materials demonstrate high resolution and clear bandstops in the near IR region.A. Ovsianikov, A. Gaidukeviciute, B. N. Chichkov, M. Oubaha, B. D. MacCraith, I. Sakellari, A. Giakoumaki, D. Gray, M. Vamvakaki, M. Farsari, and C. Fotakis© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/623872Microprocessing of dielectric optical coatings by UV laser ablation is demonstrated. Excimer laser ablation at deep UV wavelengths (248 nm, 193 nm) is used for the patterning of thin oxide films or layer stacks. The layer removal over extended areas as well as sub-μm-structuring is possible. The ablation of SiO2, Al2O3, HfO2, and Ta2O5 layers and layer systems has been investigated. Due to their optical, chemical, and thermal stability, these inorganic film materials are well suited for optical applications, even if UV-transparency is required. Transparent patterned films of SiO2 are produced by patterning a UV-absorbing precursor SiOx suboxide layer and oxidizing it afterwards to SiO2. In contrast to laser ablation of bulk material, in the case of thin films, the layer-layer or layer-substrate boundaries act as predetermined end points, so that precise depth control and a very smooth surface can be achieved. For large area ablation, nanosecond lasers are well suited; for patterning with submicron resolution, femtosecond excimer lasers are applied. Thus the fabrication of optical elements like dielectric masks, pixelated diffractive elements, and gratings can be accomplished.J. Ihlemann, J. Békési, J.-H. Klein-Wiele, and P. Simon© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/892721We applied the femtosecond laser-assisted etching technique, that is, irradiation of focused femtosecond laser pulses followed by selective chemical etching, to volume removal inside sapphire. At room temperature, volume etching only slightly advanced while residue remained inside the volume. By increasing the etching temperature, complete volume etching without residue was achieved. Complete etching was, however, accompanied by undesirable phenomena of surface pits or cracks, which are expected to be excluded through further improvement of processing.Shigeki Matsuo, Kensuke Tokumi, Takuro Tomita, and Shuichi Hashimoto© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/656490The physical properties including refractive index, Abbe number, nonlinear refractive index, microhardness and thermal expansion coefficient, and spectroscopic properties of Yb3+-doped fluorophosphate laser glasses were investigated. The results show that due to the addition of fluoride, mechanical and thermal properties are promoted, emission cross-section σemi is also greatly enhanced. The largest gain coefficient σemi·τm (0.824 pm2·ms) can be obtained with the minimum pump intensity Imin (1.112 kw/cm2). This kind of Yb3+-doped fluorophosphate glass is an excellent candidate material for Yb3+-doped host for high-power generation.Shujiang Liu and Anxian Lu© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/534951We present a short overview of recent advances in ultrashort pulse four-wave optical parametric amplification in transparent condensed bulk media with Kerr nonlinearity. Highly efficient (10% to 15% pump-to-signal energy conversion) four-wave optical parametric amplification in water and fused silica is experimentally demonstrated. The amplification process highly benefits from 1-dimensional spatial soliton propagation regime, which sets in under proper combination of cylindrical beam focusing and noncollinear phase matching geometry with millijoule pumping. Under these operating conditions, strong four-wave coupling quenches catastrophic beam break-up and filamentation, and the setup operates reasonably below the damage threshold of the nonlinear medium. The proposed methodology offers a number of advantages as compared to guided-wave configurations in gaseous media.Audrius Dubietis, Gintaras Tamošauskas, Gintaras Valiulis, and Algis Piskarskas© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/416251Since its development in 2003, the technique of Bragg grating inscription in optical fibers and waveguides with ultrafast infrared radiation and a phase mask has proven to be as simple as the standard UV-laser grating writing techniques but far more versatile. The ultrafast IR laser-based process allows for the creation of grating structures in glassy and crystalline materials that are not typically UV photosensitive. In this article, we will review the studies that have been performed at the Communications Research Centre Canada on the grating formation processes as well as applications of the ultrafast laser technique to fabricate gratings in various optical fibers and waveguides.Stephen J. Mihailov, Dan Grobnic, Christopher W. Smelser, Ping Lu, Robert B. Walker, and Huimin Ding© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2007/80536Objective. This study aimed to establish if laser irradiation induces cellular and genetic damage. Background. Phototherapy has been shown to induce wound healing in diabetic wounds, however little information is known regarding light-induced damage. Methods. Diabetic wounded fibroblasts were irradiated with 5 or 16 J/cm2 at 632.8, 830, and 1064 nm. Damage was assessed by measuring membrane and DNA damages. Cellular migration was determined by microscopy. Results. Cells irradiated with 5 J/cm2 at 632.8 and 830 nm showed a significant decrease in DNA damage while all cells irradiated with a fluence of 16 J/cm2 showed an increase in membrane and DNA damages. Conclusion. This study showed that the comet assay and LDH release were sensitive enough to pick up changes in laser-irradiated cells. This study also showed that cellular and genetic damage inflicted on diabetic wounded cells was dependent on dose and wavelength and that cells are able to recover and respond.Nicolette N. Houreld and Heidi Abrahamse© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1997/95890The nonlinear optical properties of pseudoisocyanine J-aggregates in Langmuir-Blodgett films have been investigated by means of degenerate four wave mixing (DFWM) process. The conversion efficiency of the DFWM signal and the estimated third order susceptibility were found to be comparable with those of pseudoisocyanine J-aggregates in solution under comparable resonance conditions. The intensity dependence of the converted (DFWM) signal is interpreted as resulting from different processes including saturation, exciton-exciton annihilation and secondary processes of dynamical disorder.K.-H. Feller, R. Gadonas, A. Pugzlys, and D. Möbius© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/31690The velocity distributions for the Cl(2P3/2) and Cl(2P1/2) photofragments produced by the photolysis of Cl2 at 308 nm are measured using ion imaging. The angular distributions yield anisotropy parameters of β(2P3/2)=−1.00±0.05,β(2P1/2)=−0.95±0.05, suggesting that Cl(2P3/2) and Cl(2P1/2) is essentially produced via non-adiabatic curve crossing between the lu and the 0u+ excited electronic states.Peter C. Samartzis, Theodosia Gougousi, and Theofanis N. Kitsopoulos© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/36263An experimental approach is described for obtaining highly enriched residual gas under IR multiphoton dissociation (MPD) of molecules in one cycle of irradiation. The approach is based on utilization of a pulsed molecular flow of small length (Δxfl≤1cm). The use of a short flow length leads to high values of the dissociation yield of molecules (β≃1) in the whole volume of the flow. Owing to this, high enrichment of the residual gas is achieved in one cycle of irradiation. The isotopically-selective dissociation of CF3I+ in the pulsed gasdynamic flow of a small length was studied. About 400-fold enrichment of the 13C isotope in the residual gas was obtained following irradiation of a molecular flow of CF3I of natural isotope composition by a single laser pulse. The selectivity of dissociation was measured to be α≥10G. N. Makarov, D. E. Malinovsky, and D. D. Ogurok© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/57838A sensitive comparative fluorescence microscopic approach was developed and used to study the water at the air-water interface region. An insoluble chromophore mesoc-α,β,γ,δ-tetraphenylporphine (TPP) was spread on the water. Its fluorescence spectrum indicated that the spectrum of TPP on the water surface was similar to those measured in nonpolar hydrocarbon solvents. Thus, the water at the surface was concluded to be hydrophobic and less polar than the water in the bulk.Yao-qun Li, Shinya Sasaki, Takanori Inoue, and Teiichiro Ogawa© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/78967Ozone molecules, O3, were photodissociated in the presence of N2 at 248 nm (KrF laser) to O(1D)+ O2(1∆). The O(1D) atoms were detected by generating vacuum ultraviolet laser-induced fluorescence (VUV LIF) for the 3s1D0 -2p 1D transition at 115.2 nm. The 115.2 nm probe laser was generated by frequency tripling (ω vuv=3ω) of the 345.6 nm PTP dye laser in a Xe gas cell.A. M. Sarwaruddin Chowdhury© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/82640The gas phase reactivity of Rh(a4F9/2) with N2O, O2 and NO is reported. Removal rate constants for the excited states of rhodium below 13,000cm-1 are also reported. The reaction rate of Rh(a4F9/2) with N2O is relatively temperature insensitive. The rate constants for the bimolecular reaction are described in Arrhenius form by (1.3±0.3)×10−12exp⁡(−1.3±0.8KJ/mol/RT)cm3s−1 The reaction rates of the a4F9/2 state with O2 and NO are pressure dependent. For O2, the limiting low-pressure thirdorder, K0, and limiting high-pressure second-order, K∞, room temperature rate constants in argon buffer are (6.6±0.6)×10−30cm6s−1 and (2.1±0.2)×10−11cm3s−1, respectively. For NO, K2 and K∞ are (1.3±0.2×10−30cm6s−1) and (2.1±0.4)×10−11cm3s−1, respectively. The removal rates of the excited states are faster than the ground state by a factor of 2 or more.Mark L. Campbell© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2000/13792A study on the desorption of carbendazim (methyl-2-benzimidazolecarbamate, mass = 191 amu) from a glass surface (Pyrex) has been carried out using an experimental set-up based on laser desorption and laser post-ionization followed by time-of-flight mass spectrometry. After optimization of the experimental conditions a resolution of ca. 850 was achieved at the mass of the pesticide (191 amu). All measured time-of-flight mass spectra showed not only an excellent signal to noise ratio, but also the lack of significant molecular fragmentation, except for a mass of 71 amu which was attributed to the lateral chain of the carbendazim. Neutral time-of-flight yields were measured for several desorption energies. Analysis of the corresponding velocity distributions suggests a thermal mechanism dominating the laser-induced desorption. Finally the capability of the present technique for analytical applications is also discussed. B. Bescós, J. M. Orea, and A. Gonzláez Ureña© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2000/51834Measurements in the time-domain of molecular chemiluminescence from CaCl(A2Π1/2, A2Π2/3, B2Σ+ →X2Σ+)and atomic resonance fluorescence from Ca(43P1→ 41S0) have been made in order to determine electronic branching ratios to yield CaCl(A1/2, A2/3, B) following the Cl-atom abstraction reaction of electronically excited calcium atoms, Ca[4s4p(3PJ)] , 1.888 eV above the 4s2(1S0) ground state, with CH3Cl. Ca[4s4p(3P1)] was generated by the pulsed dye-laser excitation ofground state calcium atoms at λ = 657.3 nm 21, {Ca[4s4p(n3P1)] ←Ca[4s2(1S0)]} at elevated temigeratures in the presence of CH3Cl and excess helium buffer gas in a slow flow system, kinetically equivalent to a static system. Atomic and molecular emissions were recorded following rapid Boltzmann equilibration within the Ca(43P0,1.2) spin-orbit manifold, atomic emission being restricted to the 3P1 state as the 3P0 and 3P2 states are long-lived, being so called ‘reservoir states’. Atomic fluorescence emission profiles at the resonance wavelength together with the molecular chemiluminescence emissions CaCl (A2Π1/2→X2Σ+, Δν=0, λ=621nm),CaClA2Π3/2→X2Σ+, Δν=0, λ=618nm and CaCl(B2Σ+→X2Σ+, Δν=0,  λ=593nm) were recorded. The atomic and molecular emissions demonstrated exponential decays characterised by decay coefficients which were equal under identical chemical conditions thus demonstrating the production of CaCl(A2Π1/2,3/2, B2Σ+) by direct reaction of Ca(3pJ) with CH3Cl. The combination of the time-dependences of the atomic and molecular profiles as a function of the concentration of CH3Cl together with the integrated atomic and molecular intensities, placed on a common intensity scale by calibration of the optical system against a spectral radiometer, yielded branching ratios into the A2Π1/2, A2Π3/2 and B2Σ+ states of CaCl. These were found to be as follows: A1/ (2.6±1.1)2×10−3; A2/3(1.9±0.8)×10−3 and B(3.6±2.0)×10−4. To the best of our knowledge, these data represent the first measurements of electronic branching ratios of calcium chlorides into specific molecular states for reactions of Ca(3pJ) determined in the time-domain. The results are compared with various related data for total branching ratios into electronic states studied in the single collision condition for this atomic state with CH3Cl using molecular beams. These are also compared with branching ratios of SrCl(A2Π1/2, A2Π2/3, B2Σ+) following the reaction of Sr[5s5p(3pJ)]+ CH2Cl2 investigated following pulsed dye-laser excitation where the yields of SrCl(A1/2, A3/2, B)were of similar low magnitudes.D. Husain, J. Geng, F. Castano, and M. N. Sanchez Rayo© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2000/56406The scanning-fit method was developed for the global data analysis of pump-probe data. This method is useful in cases when pulse durations are adjusted to be short compared with nuclear dynamics and long compared with the dephasing timescales. Then multiexponential functions can be used to describe the mono molecular relaxation processes and the scanning-fit method increases the accuracy of the calculated time constants, yields detailed information about their ranges of confidence and their dependency from each other. In this paper we describe the method in detail and demonstrate its application to simulated data. Additionally, we report about the results which were obtained from scanning-fit analysis in case of the photoisomerization of pinacyanol and the light induced processes in phycocyanobilin.Mark Bischoff, Gregor Stobrawa, and Sabine Rentsch© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2000/94548The degenerate four wave mixing (DFWM) spectrum of the A(1A2)← X(1A1) and B(1B1)← X(1A1) transitions of SO2 in the 299.5–305 nm region is presented. It has been found that the DFWM signal intensities are proportional to the cube of laser intensity and the square of SO2 pressure. The DFWM signal increases dramatically with the pressure of N2 as a buffer gas. The enhancement of the DFWM signal can be mainly attributed to the thermal grating contribution. Shiming Shi, Deying Chen, Qike Zheng, Maria Person, and Qizong Qin© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2000/98130A novel hetero-metallic binuclear cluster WS4Co(dppe)(DMF) has been synthesized and characterized. The crystal has a structure of monoclinic space group P21. Ab initio CPHF calculations are performed on the static first hyperpolarizabilities of the molecular building blocks of the cluster. The microscopic structural origin of nonlinear optical properties are discussed in-depth. The charge-transfer between tungsten ion and cobalt ion in a molecular building block critically contributes to the optical nonlinearity, while the joint effect of the ligands makes sufficient enhancements. The study is helpful to search for novel IR nonlinear optical materials among the transition metal cluster compounds.Kechen Wu, Ping Lin, Xintao Wu, and Ling Chen© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/17364High resolution Doppler-free laser techniques are used in beam experiments to improve the spectroscopic description of complex diatomic molecules. The case of TiO is considered here for its implication in reaction dynamics studies and its interest in Astrophysics. Two absorption bands in the visible have been analyzed: B3Π−X3 Δ(1−0) and c1Φ−a1 Δ(0−0). Owing to accurate wavenumber measurements, it has been possible to extend the analysis to high rotational quantum numbers and to carry out detailed spectroscopic calculations. They show that a careful revisiting of the TiO electronic structure is necessary. R. Vetter, P. Luc, and C. Amiot© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/25701Multiphoton dissociation of ketene was studied at 290.5 nm after irradiation of the first excited singlet state with two different laser pulsewidths of 4 ns and 10 ps. Analysis of the photofragment fluorescence spectra in the two time domains sheds light on the mechanisms that are responsible for the production of the observed CH(A2Δ),  (B2Σ−) and C2(d3Πg) photofragments. Multiphoton ionization of cyclohexane induced by a visible laser at 581 nm and its second harmonic at 290.5 nm was measured in the above mentioned pulse duration regimes. Study of the dependence of the total ionization signal on pressure and laser energy helps to clarify the role played by the giant resonance of this molecule at 84000 cm-1 in the photoionization process. M. Castillejo, M. Martín, and R. de Nalda© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/29272Pure CF3Br and mixtures of this substance with monoatomic (He, Ar and Xe), homonuclear diatomic (H2, D2, N2), polyatomic gases (CF4) and NO have been irradiated with a TEA CO2 laser. Carbon-13 enrichment factor and carbon-13 selectivity have been estimated from the mass spectrometric analysis of the undissociated CF3Br as a function of excitation wavelength, fluence, temperature and pressure. The irradiating wavelength is a crucial parameter to achieve enrichment. The nature of the added gas also affects considerably selectivity. Best enrichment is achieved in mixtures with NO due to its radical-like character.J. I. del Barrio, R. Fernández Cézar, and F. M. G.- Tablas© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1993/98452C2F4, molecules have been for the first time directly proved to be generated in the reaction of vibrationally-excited molecules CF2HCl. The contribution of this reaction to CF2HCl multiphoton dissociation (MPD) products formation was shown to become predominant at the initial CF2HCl pressures about ten Torr. Also fast relaxation of the highly excited molecules CF2HCl on the product molecules C2F4 was discovered.V. A. Dimand, K. K. Maltzev, A. A. Nadeikin, A. I. Nikitin, A. M. Velichko, and A. V. Vnukov© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/63741ZEro Kinetic Energy (ZEKE) spectroscopy relies on electrons produced through delayed field ionization of the narrow band of high-n Rydberg states which exist just below the ionization limit of each ionic eigenstate. Using the unique properties of these weakly bound, stable, high-n Rydberg states (ZEKE states) below the ionization limit rather than the unbound states above the limit, as in PES, leads to an improvement in resolution of more than two orders of magnitude. Several different types of ZEKE experiments, each designed to probe the formation and stability of these states, are presented here. These experiments were performed with pulsed and static electric fields of different magnitude and duration at different ion concentrations. The results indicate an enhanced ZEKE state decay with increasing electric field strengths and an enhanced formation and stabilization with increasing ion concentrations. A strong interplay between field strength and ion concentration ZEKE state formation is demonstrated. The strong influence of electric fields and ion concentrations on the physical properties of the ZEKE state, above and below the classical ionization threshold, is also demonstrated through late time (tens of microseconds) decay rate measurements. A. Held and E. W. Schlag© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/68314A method for the analysis of carbendazim in peper has been developed using Supercritical Fluid Extraction (SFE) for the sample preparation and the combination of Laser Desorption (LD) with Resonance Enhanced Multi-Photon Ionization (REMPI) coupled to Time-of-Flight Mass Spectrometry (TOF-MS) for the detection. The method allows the analysis of carbendazim in pepper reducing the sample preparation step and avoiding the matrix effects present in classical GC and HPLC techniques, as well as the problems related to the labile properties of carbendazim. The detection limit obtained is of the same order of magnitude as the generally employed HPLC technique, but with higher sensitivity and easier sample preparation. B. Bescós, J. M. Orea, C. Montero, A. González Ureña, A. Valverde, and A. Aguilera© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1998/71976An overview of recent results obtained by our group on the development of polymeric solid-state media incorporating either Rhodamine or Coumarin dyes is presented. The effect on the laser performance of the rigidity and viscoelastic properties of the polymeric matrix has been investigated. Lasing efficiencies similar to those found in ethanolic solution, and improved photochemical stability, as compared with that obtained in previous polymeric materials, were demonstrated for solid solutions of Rhodamine 6G (Rh6G) in appropriate copolymer formulations of 2-hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA). Further improvements in photostability were obtained when modified Rh6G molecules were copolymerized with HEMA and MMA. When samples of this new highly homogeneous gain medium were placed in a rotating system, where the laser medium was scanned in a continuous way, a stable laser output with no sign of degradation after 500,000 shots was accomplished for transversal pumping at 337 nm with 1.7 mJ pulses from a N2-laser at 2 Hz repetition rate. A. Costela, I. Garcia-Moreno, J. M. Figuera, F. Amat-Guerri, and R. Sastre© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1999/39826Pulsed laser ablation of TiO2 at 355 nm and 532 nm has been investigated using an angleand time-resolved quadrupole mass spectrometric technique. The major ablated species include O (m/e = 16), O2 (m/e = 32), Ti (m/e = 48), TiO (m/e = 64) and TiO2 (m/e = 80). The time-of-flight (TOF) spectra of ablated species are measured for the ionic and neutral ablated species, and they can be fitted by a Maxwell – Boltzmann (M – B) distribution with a center-of-mass velocity. The measured angular distributions of the ionic species (O+ and Ti+) and the neutral species (O and Ti) can be fitted with cos⁡nθ and a cos⁡θ + (1−a)cos⁡nθ, respectively. In addition, a continuous wave oxygen molecular beam is introduced into the ablated plume, and the enhancement of the signal intensities of TiO is observed. It implies that the ablated Ti atoms/ions species can react with ambient oxygen molecules in the gas phase. In the meanwhile, the physicochemical mechanism of pulsed laser ablation of TiO2 is discussed. Yongxin Tang, Zhenhui Han, and Qizong Qin© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1999/43598The interaction of CS2 with intense short pulse laser radiation is studied, experimentally using time-of-flight mass spectroscopy. Laser pulses of 0.5 and 5 psec at 248 and 496 nm have been used in order to investigate the effect of the wavelength and the pulse duration on the molecular ionization and fragmentation. As shown, for low enough intensities the parent molecular ion is present as the most important peak in all cases. Increasing the intensity results in extensive fragmentation, where the molecular parent ion remains always the more intense mass peak at 496 nm while at 248 nm S+ dominates the mass spectra. Finally, the production of multiply charged fragments is more efficient at the longer wavelength used. E. Koudoumas, R. De Nalda, C. Fotakis, and S. Couris© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/1999/48171Time integrated Laser Induced Breakdown Spectroscopy was applied to the study of real samples of polychromes. Two samples respectively from the Spanish Baroque and from the XV century were analysed. The time integrated spectra showed negligible contribution of continuum background emission. The spectra of the Baroque sample indicated the presence of vermilion; this was confirmed by Near Infrared Fourier Transform Spectroscopy. LIBS spectra of the XV century sample showed Ca, Al, Mg, Na and Pb lines and the molecular emissions CN(B-X) and C2(d-a). Relative spectral intensities were measured as a function of the number of laser pulses delivered on the same position of the sample. The LIBS analysis was compared to an exhaustive analytical study.Margarita Martin, Marta Castillejo, Ricardo Torres, and Diego Silva© 2008, Hindawi Publishing Corporation. All rights reserved.