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Showing papers by "IPG Photonics published in 2011"


Patent
26 Sep 2011
TL;DR: In this article, a method of processing interferograms is provided based on homodyne filtering, and a method for generating a record of a material modification process using an interferometry output is provided.
Abstract: Methods and systems are provided for using optical interferometry in the context of material modification processes such as surgical laser or welding applications. An imaging optical source that produces imaging light. A feedback controller controls at least one processing parameter of the material modification process based on an interferometry output generated using the imaging light. A method of processing interferograms is provided based on homodyne filtering. A method of generating a record of a material modification process using an interferometry output is provided.

160 citations


Journal ArticleDOI
TL;DR: A review of the main mechanisms involved in the mediation of mineral precipitation by microorganisms can be found in this paper, including supersaturation caused by metabolic activity, the triggering of nucleation by production of more or less specific organic molecules, and the impact of mineral growth.

145 citations


Journal ArticleDOI
TL;DR: Recent progress in fabrication and mid-IR lasing of transition metal doped II-VI single crystal and thermo-diffusion doped polycrystalline and hot-pressed ceramic gain media as well as nano and micro-crystaline laser active powders, powders in the liquid suspension, polymer-film, thin film waveguides and chalcogenides glass composites is reported as discussed by the authors.
Abstract: Recent progress in fabrication and mid-IR lasing of transition metal doped II-VI single crystal and thermo-diffusion doped polycrystalline and hot-pressed ceramic gain media as well as nano and micro-crystalline laser active powders, powders in the liquid suspension, polymer-film, thin film waveguides and chalcogenides glass composites is reported.

101 citations


Journal ArticleDOI
TL;DR: In this article, the presence of As influences the type of biogenic Fe(III) (oxyhydr)oxide minerals formed by the nitrate-reducing Fe(II)-oxidizing bacterium Acidovorax sp. strain BoFeN1.

100 citations


Journal ArticleDOI
TL;DR: In this article, microstructural observations with Raman spectroscopy on carbonaceous material (RSCM), phase equilibria modelling and U-Pb dating of titanite were combined to delineate the metamorphic history of a well-exposed section through the South Tibetan Detachment System (STDS) in the Dzakaa Chu valley of Southern Tibet.
Abstract: This study combines microstructural observations with Raman spectroscopy on carbonaceous material (RSCM), phase equilibria modelling and U–Pb dating of titanite to delineate the metamorphic history of a well-exposed section through the South Tibetan Detachment System (STDS) in the Dzakaa Chu valley of Southern Tibet. In the hanging wall of the STDS, undeformed Tibetan Sedimentary Series rocks consistently record peak metamorphic temperatures of ∼340 °C. Temperatures increase down-section, reaching ∼650 °C at the base of the shear zone, defining an apparent metamorphic field gradient of ∼310 °C km−1 across the entire structure. U–Th–Pb geochronological data indicate that metamorphism and deformation at high temperatures occurred over a protracted period from at least 20 to 13 Ma. Deformation within this 1-km-thick zone of distributed top-down-to-the-northeast ductile shear included a strong component of vertical shortening and was responsible for significant condensing of palaeo-isotherms along the upper margin of the Greater Himalayan Series (GHS). We interpret the preservation of such a high metamorphic gradient to be the result of a progressive up-section migration in the locus of deformation within the zone. This segment of the STDS provides a detailed thermal and kinematic record of the exhumation of footwall GHS rocks from beneath the southern margin of the Tibetan plateau.

87 citations


Journal ArticleDOI
01 Jun 2011-Lithos
TL;DR: In the Schistes Lustres of Alpine Corsica (France), serpentinized mantle rocks are associated with continental basement and meta-volcanic/sedimentary cover rocks as mentioned in this paper.

79 citations


Journal ArticleDOI
TL;DR: Using Raman spectroscopy and 27Al NMR spectrograms, this article determined the structure of aluminum network as a function of MO/Al2O3 ratio with M corresponds to different alkaline-earth cations.
Abstract: Aluminate glasses are important materials from a fundamental structural point of view because Al is the only network former. They present also a technological interest because of their good IR transmission and ultralow optical losses. Aluminum in glasses of the system MO–Al2O3 (M = Ca, Sr, Ba) can have different coordination numbers, essentially 4 and 6, as a function of the MO/Al2O3 ratio. Using Raman spectroscopy and high field 27Al NMR spectroscopy, we have determined the structure of aluminum network as a function of MO/Al2O3 ratio with M corresponds to different alkaline–earth cations. Al is essentially in four-fold coordination with different amounts for Al2O3 between 50 and 75% but varies between Q2 and Q4 species as a function of MO/Al2O3 ratio where Q is tetrahedral species and n the number of bridging oxygen.

75 citations


Journal ArticleDOI
05 Oct 2011-PLOS ONE
TL;DR: It is demonstrated that uranium exerts a permanent high pressure on soil bacterial communities and the existence of a uranium redox cycle mediated by bacteria in the soil is suggested.
Abstract: This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.5% U in mass were analyzed and compared with nearby control soils containing trace uranium. EXAFS and XRD analyses of soils revealed the presence of U(VI) and uraniumphosphate mineral phases, identified as sabugalite and meta-autunite. A comparative analysis of bacterial community fingerprints using denaturing gradient gel electrophoresis (DGGE) revealed the presence of a complex population in both control and uranium-rich samples. However, bacterial communities inhabiting uraniferous soils exhibited specific fingerprints that were remarkably stable over time, in contrast to populations from nearby control samples. Representatives of Acidobacteria, Proteobacteria, and seven others phyla were detected in DGGE bands specific to uraniferous samples. In particular, sequences related to iron-reducing bacteria such as Geobacter and Geothrix were identified concomitantly with iron-oxidizing species such as Gallionella and Sideroxydans. All together, our results demonstrate that uranium exerts a permanent high pressure on soil bacterial communities and suggest the existence of a uranium redox cycle mediated by bacteria in the soil.

69 citations


Journal ArticleDOI
TL;DR: In this article, the authors studied the geochemistry of eleven small watersheds around Basse-Terre volcanic island in the French West Indies during different hydrological regimes from 2006 to 2008 (i.e. low water level versus floods).

68 citations


Journal ArticleDOI
TL;DR: It is shown that the use of cryo‐TEM instead of conventional microscopy provides detailed information of the successive iron biomineralization stages in anaerobic nitrate‐reducing iron‐oxidizing bacteria and offers a detailed view of the exceptional preservation of protein globules and the peptidoglycan within the Fe‐mineralized cell walls of these bacteria.
Abstract: Iron-oxidizing bacteria are important actors of the geochemical cycle of iron in modern environments and may have played a key role all over Earth's history. However, in order to better assess that role on the modern and the past Earth, there is a need for better understanding the mechanisms of bacterial iron oxidation and for defining potential biosignatures to be looked for in the geologic record. In this study, we investigated experimentally and at the nanometre scale the mineralization of iron-oxidizing bacteria with a combination of synchrotron-based scanning transmission X-ray microscopy (STXM), scanning transmission electron microscopy (STEM) and cryo-transmission electron microscopy (cryo-TEM). We show that the use of cryo-TEM instead of conventional microscopy provides detailed information of the successive iron biomineralization stages in anaerobic nitrate-reducing iron-oxidizing bacteria. These results suggest the existence of preferential Fe-binding and Fe-oxidizing sites on the outer face of the plasma membrane leading to the nucleation and growth of Fe minerals within the periplasm of these cells that eventually become completely encrusted. In contrast, the septa of dividing cells remain nonmineralized. In addition, the use of cryo-TEM offers a detailed view of the exceptional preservation of protein globules and the peptidoglycan within the Fe-mineralized cell walls of these bacteria. These organic molecules and ultrastructural details might be protected from further degradation by entrapment in the mineral matrix down to the nanometre scale. This is discussed in the light of previous studies on the properties of Fe-organic interactions and more generally on the fossilization of mineral-organic assemblies.

67 citations


Journal ArticleDOI
TL;DR: In this paper, the authors carried out paleomagnetic sampling of a similar to 750 m sequence of the Karoo large igneous province (Naude's Nek Pass, South Africa).
Abstract: We have carried out paleomagnetic sampling of a similar to 750 m sequence of the Karoo large igneous province (Naude's Nek Pass, South Africa). K-Ar dating (Cassignol-Gillot) has been performed on four samples from the 650 m upper unit (mean age 179.2 +/- 1.8 Ma) and a sample from the lower unit (184.8 +/- 2.6 Ma). A succession of two phases of volcanism is suggested. The lower 25 flows (115 m thick) have recorded a reversed polarity; the next 23 flows (135 m thick) are transitional and contribute a detailed record of the "Van Zijl" (1962) Jurassic reversal. The upper 38 flows (500 m thick) have normal polarity. Directional groups (DGs) of lava flows with quasi-identical remanence directions indicate eruption durations too short to have recorded geomagnetic secular variation and hence are interpreted as single eruptive events. Altogether, 19 DGs and 10 sheet lobes yield a sequence of 29 distinct directions. This could correspond to a total eruptive activity shorter than 3000 years, less than one per mil of the total duration over which the section was emplaced. We obtain a new paleomagnetic pole for South Africa at similar to 180 Ma (lambda = 75.2 degrees N, phi = 276.4 degrees E, A(95) = 5.8 degrees, N = 19), which is consistent with earlier reports.

Journal ArticleDOI
Abstract: The Southwest Indian Ridge is characterized by frequent outcrops of mantle rocks in a very slow spreading context. In situ measurements of trace element concentrations in pyroxenes of these rocks, and associated petrogenetic modeling, are reported. Overall, the measured compositions cover the whole range typically observed for abyssal peridotites. The greatest subkilometer-scale compositional variability is observed in the region east of the Melville fracture zone. The best explanation for the observed variability is given by concurrent melting and migration of melts strongly enriched in the most incompatible rare earth elements, such as those produced by a garnet-bearing source, or by refertilization with mixed garnet- and spinel-derived partially aggregated melts. Because the regionally associated basalts bear no “garnet signature” in their chemical compositions, we conclude that the residual mantle preserves the signature of a mantle source component that does not appear in the erupted magmas. Comparison between along-axis variations of basalt isotopic compositions and peridotite chemical compositions suggests that local isotopic enrichments displayed by some basalts can be associated with the “garnet signature” in the peridotite and that our sampling represents only a fraction of the global variability of the subaxial mantle. To the west of the Melville fracture zone, samples are more depleted and homogeneous at dredge scale. In addition to containing enriched components, petrologic modeling indicates that the peridotitic mantle beneath the entire section underwent (previous?) partial melting in the garnet stability field before melting at lower pressures.

Patent
11 Feb 2011
TL;DR: In this article, the authors present an optical transceiver defined by an MSA agreement with integrated performance monitoring (PM); optical layer operations, administration, maintenance, and provisioning (OAMP) and alarming in optical transceivers, such as multi-source agreement (MSA)-defined modules.
Abstract: The present disclosure provides integrated performance monitoring (PM); optical layer operations, administration, maintenance, and provisioning (OAMP and alarming in optical transceivers, such as multi-source agreement (MSA)-defined modules. The present disclosure includes an optical transceiver defined by an MSA agreement with integrated PM and alarming for carrier-grade operation. The integration preserves the existing MSA specifications allowing the optical transceiver to operate with any compliant MSA host device. Further, the host device can be configured through software to retrieve the PM and alarming from the optical transceiver. The optical transceiver can include CFP and variants thereof (e.g., future CFP2, CDFP, CXP), OIF-MSA-100GLH-EM-01.0, CCRx (Compact Coherent Receiver), Quad Small Form-factor Pluggable (QSFP) and variants thereof (e.g., future QSFP+, QSFP2), 10×10 MSA, XFP, XPAK, XENPAK, X2, XFP-E, SFP, SFP+, 300-pin, and the like.

Journal ArticleDOI
TL;DR: To investigate how this particular ecosystem functions, the bacterial community was characterized in water and sediments by 16S rRNA encoding gene library analysis and several GroEL orthologs expressed by the community were characterized, and the active members of the prokaryotic community inhabiting the creek sediments were identified.
Abstract: Acid mine drainage of the Carnoules mine (France) is characterized by acid waters containing high concentrations of arsenic and iron. In the first 30 m along the Reigous, a small creek draining the site, more than 38% of the dissolved arsenic was removed by co-precipitation with Fe(III), in agreement with previous studies, which suggest a role of microbial activities in the co-precipitation of As(III) and As(V) with Fe(III) and sulfate. To investigate how this particular ecosystem functions, the bacterial community was characterized in water and sediments by 16S rRNA encoding gene library analysis. Based on the results obtained using a metaproteomic approach on sediments combined with high-sensitivity HPLC-chip spectrometry, several GroEL orthologs expressed by the community were characterized, and the active members of the prokaryotic community inhabiting the creek sediments were identified. Many of these bacteria are β-proteobacteria such as Gallionella and Thiomonas, but γ-proteobacteria such as Acidithiobacillus ferrooxidans and α-proteobacteria such as Acidiphilium, Actinobacteria, and Firmicutes were also detected.

Journal ArticleDOI
TL;DR: The present study illustrates how the methodology described here, which combines HRTEM and polarization-dependent synchrotron-based STXM imaging, offers an interesting new approach for investigating biomineralizing systems at the nm-scale.

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed the positions of virtual geomagnetic poles (VGP) for the directional groups and individual directions jointly for the two sections (more than 160 lava flows) of the Abagalakh and Listvyanka sections in the Norilsk region.
Abstract: Detailed paleomagnetic studies have shown that the effusive Permian-Triassic traps in the Kotui River valley were formed as the result of volcanic activity, which occurred in the form of volcanic pulses and individual eruptions with net duration of at most 7000–8000 years, excluding the periods of volcanic quiescence. According to the analysis of the paleomagnetic data earlier obtained by Heunemann and his coauthors [2004b] on the Abagalakh and Listvyanka sections in the Norilsk region, those geological units were formed during 25 volcanic pulses and separate eruptions, which all lasted up to 8000 years altogether, whereas the total time of formation (including the periods of volcanic quiescence) exceeded 10000–100000 years for the Norilsk section and was probably a bit shorter for the Kotui section. Comparison of the positions of virtual geomagnetic poles calculated for the Norilsk and the Kotui sections provides no grounds to suggest that these sections were formed at different geological times. The scatter in the positions of the virtual geomagnetic poles (VGP) for the directional groups and individual directions (58 altogether) jointly for the two sections (more than 160 lava flows) indicates that the secular geomagnetic variations at the Permian-Triassic boundary had similar amplitudes to those that occurred in the past 5 Ma.

Proceedings ArticleDOI
13 Feb 2011
TL;DR: In this paper, recent advances in Cr2+ and Fe2+ doped mid-IR polycrystalline, hot-pressed ceramic, waveguides, powders, powderers in the liquid suspension and polymer-film, and quantum dot laser materials fabrication and lasing under optical excitation are presented.
Abstract: Recent advances in Cr2+ and Fe2+ doped mid-IR polycrystalline, hot-pressed ceramic, waveguides, powders, powders in the liquid suspension and polymer-film, and quantum dot laser materials fabrication and lasing under optical excitation are presented.

Journal ArticleDOI
TL;DR: In this article, the authors used the wide-angle seismic (WAS) and gravity data of the Encens survey to determine the deep crustal structure of the north-eastern Gulf of Aden nonvolcanic passive margin.
Abstract: The wide-angle seismic (WAS) and gravity data of the Encens survey allow us to determine the deep crustal structure of the north-eastern Gulf of Aden non-volcanic passive margin. The Gulf of Aden is a young oceanic basin that began to open at least 17.6 Ma ago. Its current geometry shows first- and second-order segmentation: our study focusses on the Ashawq–Salalah second-order segment, between Alula–Fartak and Socotra–Hadbeen fracture zones. Modelling of theWAS and gravity data (three profiles across and three along the margin) gives insights into the first- and second-order structures. (1) Continental thinning is abrupt (15–20 km thinning across 50–100 km distance). It is accommodated by several tilted blocks. (2) The ocean–continent transition (OCT) is narrow (15 km wide). The velocity modelling provides indications on its geometry: oceanic-type upper-crust (4.5 km s−1) and continentaltype lower crust (>6.5 km s−1). (3) The thickness of the oceanic crust decreases from West (10 km) to the East (5.5 km). This pattern is probably linked to a variation of magma supply along the nascent slow-spreading ridge axis. (4) A 5 km thick intermediate velocity body (7.6 to 7.8 kms−1) exists at the crust-mantle interface below the thinned margin, the OCT and the oceanic crust. We interpret it as an underplated mafic body, or partly intruded mafic material emplaced during a ‘post-rift’ event, according to the presence of a young volcano evidenced by heat-flow measurement (Encens-Flux survey) and multichannel seismic reflection (Encens survey). We propose that the non-volcanic passive margin is affected by post-rift volcanism suggesting that post-rift melting anomalies may influence the late evolution of non-volcanic passive margins.

Journal ArticleDOI
TL;DR: In this article, the authors present an experimental study of the dynamics of a plume generated from a small heat source in a high Prandtl number fluid with a strongly temperature-dependent viscosity.
Abstract: We present an experimental study of the dynamics of a plume generated from a small heat source in a high Prandtl number fluid with a strongly temperature-dependent viscosity. The velocity field was determined with particle image velocimetry, while the temperature field was measured using differential interferometry and thermochromic liquid crystals. The combination of these different techniques run simultaneously allows us to identify the different stages of plume development, and to compare the positions of key-features of the velocity field (centers of rotation, maximum vorticity locations, stagnation points) respective to the plume thermal anomaly, for Prandtl numbers greater than 103. We further show that the thermal structure of the plume stem is well predicted by the constant viscosity model of Batchelor (Q J R Met Soc 80: 339–358, 1954) for viscosity ratios up to 50.

Journal ArticleDOI
TL;DR: The micro-structural organization of the micrabaciid skeleton is consistent with their monophyletic status based on macromorphological and molecular data, and points to a diversity of organic matrix-mediated biomineralization strategies in Scleractinia.
Abstract: Micrabaciids are solitary, exclusively azooxanthellate deep-sea corals belonging to one of the deepest-living (up to 5,000 m) scleractinian representatives. All modern micrabaciid taxa (genera: Letepsammia, Rhombopsammia, Stephanophyllia, Leptopenus) have a porous and often very fragile skeleton consisting of two main microstructural components known also from other scleractinians: rapid accretion deposits and thickening deposits. However, at the microstructural level, the skeletal organization of the micrabaciids is distinctly different from that of other scleractinians. Rapid accretion deposits consist of alternations of superimposed "microcrystalline" (micrometer-sized aggregates of nodular nanodomains) and fibrous zones. In contrast to all shallow-water and sympatric deep-water corals so far described, the thickening deposits of micrabaciids are composed of irregular meshwork of short (1-2 mu m) and extremely thin (ca. 100-300 am) fibers organized into small, chip-like bundles (ca. 1-2 mu m thick). Longer axes of fiber bundles are usually subparallel to the skeletal surfaces and oriented variably in this plane. The unique microstructural organization of the micrabaciid skeleton is consistent with their monophyletic status based on macromorphological and molecular data, and points to a diversity of organic matrix-mediated biomineralization strategies in Scleractinia. J. Morphol. 272:191-203, 2011. (C) 2010 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: In this article, the authors used electron paramagnetic resonance (EPR) and Fourier transform infrared spectroscopies to track the evolution of suspended matter using a ubiquitous chemical species, FeIII complexed to organic matter (FeOM).

Journal ArticleDOI
TL;DR: In this article, a low cost, high power, and high efficiency laser can yield large area functional indium tin oxide (ITO) films in a process that carries substantial promise for potential industrial implementation.
Abstract: Indium tin oxide (ITO) coatings are widely used as transparent electrodes for optoelectronic devices. The most common preparation methods are sputtering, evaporation, and wet chemical deposition. ITO coatings can also be manufactured by solution deposition of ITO nanoparticles followed by furnace thermal annealing with the major motivation to reduce equipment investment. However, conventional furnace annealing is energy intensive, slow, and limited by the peak processing temperature. To overcome these constraints, we suggest using a laser beam for ITO nanoparticle annealing over a large area. It is shown in the present study that a low cost, high power, and high efficiency laser can yield large area functional ITO films in a process that carries substantial promise for potential industrial implementation. Furthermore, laser annealing generates higher electrical conductivity than conventional, thermally annealed nanoparticle films. The optical and electrical properties of the annealed ITO films can also be altered by adjusting laser parameters and environmental gases.

Journal ArticleDOI
TL;DR: In this article, the authors studied the convective patterns developing at high Rayleigh numbers and intermediate viscosity ratios in a fluid with a strongly temperature-dependent viscous material.

Journal ArticleDOI
TL;DR: The results of an extensive survey of both natural hot springs and production wells across Tunisia, aimed at investigating the spatial distribution of thermal fluids' geochemical characteristics and He-C isotopic composition are reported in this article.

Journal ArticleDOI
TL;DR: In this paper, the authors investigate the fate of organic matter in the soil-water continuum in the Rio Negro basin through description of the composition of OM potentially mobile at different stages of podzol development and exploration of evidence for contributions from different soil horizons to the exportation of OM into waters.
Abstract: In the Rio Negro basin, podzols develop at the expense of clay-depleted laterites through localized and spectacular weathering fronts. This natural process leads to the remobilization of previously accumulated organic matter (OM) which is redistributed within soil profiles and exported towards rivers, hence their typical black coloration. We investigate the fate of OM in the soil–water continuum in the Rio Negro basin through description of the composition of OM potentially mobile at different stages of podzol development and exploration of evidence for contributions from different soil horizons to the exportation of OM into waters. OM was water-extracted from seven key soil samples from a sequence representative of the transition between latosol and podzol on the low elevation plateaux of the Rio Negro basin, thus enabling following both vertical and lateral differentiations. The chemical structure of freeze-dried samples, investigated using 13C nuclear magnetic resonance and thermally assisted hydrolysis and methylation (THM), shows contrasting features depending on the horizon considered. The bulk features of water extracts were first compared with samples collected in the water-tables and rivers draining the soil sequence. A molecular level comparison was then performed with groundwater draining the well-developed podzol. This approach evidenced a contribution from deep horizons of well-developed podzols. It highlights that OM is certainly remobilised after being accumulated in Bh horizons during the development of podzols through accumulation of OM redistributed from surface horizons. The identification of specific compounds opens new perspective to trace a “podzolic origin” of OM in drainage networks.

Journal ArticleDOI
TL;DR: In this paper, the authors combine high-spatial resolution analyses, including NanoSIMS, Raman, SXM, AFM, SEM and TEM, to investigate the composition, mineralogy and ultrastructure of the giant tetractines of Leuconia johnstoni Carter, 1871 (Baeriidae, Calcaronea) and the organization of surrounding cells.

Journal ArticleDOI
TL;DR: In this paper, the sedimentation pattern along the margin of the Dhofar margin was investigated and two debris flow events occurred at the foot of the slope, one affecting a wide area of the margin, marking a major change in sedimentation and the second event is associated with a shift of sedimentary deposition from the slope toward the basin.
Abstract: An investigation of the sedimentation pattern along the Dhofar margin allows us to describe its late-stage evolution. After the accumulation of a thick post-rift sedimentary succession, two debris flow events occurred at the foot of the slope. The first event, affecting a wide area of the margin, marks a major change in sedimentation. The second event is associated with a shift of sedimentary deposition from the slope toward the basin. This latter debris flow was caused by an uplift phase, and highlights two distinct deformational styles in the eastern and western part of the Dhofar margin. Both events occurred very late in the history of the margin, at least 7.6 Ma after the end of the rifting phase (35-17.6 Ma).

Proceedings ArticleDOI
TL;DR: In this paper, the authors reported record nanosecond output energies of gain-switched Cr:ZnSe lasers pumped by H 2 Raman shifted Nd:YAG laser pumping, achieving 3.1 mJ of output energy, 52% slope efficiency and 110 nm linewidth at a wavelength of 2.47 μm.
Abstract: In this paper, we report record nanosecond output energies of gain-switched Cr:ZnSe lasers pumped by Q-switched Cr:Tm:Ho:YAG (100 ns @ 2.096 μm) and Raman shifted Nd:YAG lasers (7 ns @ 1.906 μm). In these experiments we used Brewster cut Cr:ZnSe gain elements with a chromium concentration of 8x10 18 cm -3 . Under Cr:Tm:Ho:YAG pumping, the first Cr:ZnSe laser demonstrated 3.1 mJ of output energy, 52% slope efficiency and 110 nm linewidth centered at a wavelength of 2.47 μm. Maximum output energy of the second Cr:ZnSe laser reached 10.1 mJ under H 2 Raman shifted Nd:YAG laser pumping. The slope efficiency estimated from the input-output data was 47%.

Journal ArticleDOI
TL;DR: In this paper, a quantitative determination of Fe 3+ /ΣFe ratios using the electron microprobe is presented for glasses, based on the shift of the Fe-L α peak position between Fe 3 + and Fe 2+, resulting from differences in self-absorption.
Abstract: A quantitative determination of Fe 3+ /ΣFe ratios using the electron microprobe is presented for glasses. The measurements are based on the shift of the Fe- L α peak position between Fe 3+ and Fe 2+ , resulting from differences in self-absorption. We present new calibration curves for glasses with Fe contents as low as 2 wt.% Fe. This method was used for glasses from a metasomatized spinel lherzolite (Massif Central, France) in which highly vesicular glass associated with secondary minerals occurs in reaction pockets around corroded Cr-spinels. The glass was found to be oxidized homogeneously with Fe 3+ /ΣFe ≈ 0.70 (measured with an uncertainty of ±0.06), in contrast with the value of ∼0.15 that would correspond to the former melt under f O 2 conditions inferred from secondary minerals. The glass oxidation probably results from the dissociation of the melt-water content under degassing, prior to local hematite depositions (spinel rims and crack fillings).

Patent
28 Jan 2011
TL;DR: In this paper, a welding tool is configured with a housing enclosing a fiber laser system which is operative to produce a weld seam for connecting two workpieces, and a focusing optic is configured to focus the output beam of the system so that it propagates through an elongated slit formed in the bottom of the housing.
Abstract: A welding tool is configured with a housing enclosing a fiber laser system which is operative to produce a weld seam for connecting two workpieces. The fiber laser system includes a focusing optic configured to focus the output beam of the system so that it propagates through an elongated slit formed in the bottom of the housing. The fiber laser system is capable to move along a predetermined path extending parallel to the longitudinal direction of the slit and limited by the perimeter thereof. The output beam is generated only when the slit sits upon at least one of the workpieces.