IPG Photonics

About: IPG Photonics is a based out in . It is known for research contribution in the topics: Laser & Fiber laser. The organization has 903 authors who have published 1241 publications receiving 63339 citations.

Simulation of the 2004 tsunami of Les Saintes in Guadeloupe (Lesser Antilles)

Abstract: Subduction zones are areas with significant tectonic activity, complex fault systems, volcanic edifices and growth of islands. Earthquakes in this context are associated with sudden subsidence or uplift of the sea floor with the potential to trigger landslides and tsunamis. A tsunami initiated by a megathrust earthquake can generate strong currents, and is able to carry massive quantities of sediments. The inhabited islands and coasts near subduction areas are threatened by those destructive earthquakes and tsunamis. The arc of the Lesser Antilles which formed due to the plunge of the Atlantic oceanic plate under the Caribean plate, is one of them. The tsunamigenic earthquakes in this region are rare, poorly documented and the only available data are qualitative (observations of coseismic displacement, intensity of the damages). Quantitative data is lacking as no seismograms or tide-gauge were set up before 1968. This lack of data increases the uncertainty on the existent fault models and the shortness of the catalog of seismicity does not enable a good analysis of the recurence cycle of the megathrust earthquakes. The most recent tsunamigenic earthquake occured in 2004 in the area of Les Saintes normal fault system. This Mw6.3 earthquake generated small waves with 2m of run-up in several bays of Les Saintes, a group of island in the South of Guadeloupe. A recent survey done on the fault scarp revealed important coseismic displacement at the surface which had not been predicted in the seismic source models resulting from the joint inversion of teleseismic and GPS data. Tsunami simulations of those different models of fault enable the calculation of the associated time arrivals and water heights of the waves. Compared to the reported observation, those results give complementary informations and additional constrains on the source parameters.

Beam coupler alignment system and method

Abstract: A beam coupler alignment system for a fiber laser system is disclosed. The system includes a focus adjust collimator assembly having an inner and outer housing assembly portion. The inner assembly includes a coupler housing assembly and a modified lens housing received within and adjustable relative to via a mechanism configured and arranged to apply an asymmetric binding force in a predictable and repeatable manner. A lever assembly contacts the lens housing and exerts an off-center (asymmetric) force relative to coupler housing assembly creating a friction bind eliminating X and Y axis movement yet allowing Z axis movement with minimal effort. The assembly may further include an alignment mechanism configured and arranged to optically align an input collimator unit and an output collimator unit of a complex fiber laser system about a common optical axis using the proposed assembly.

Structure et propriété des verres et des liquides : le rôle de l'aluminium

Abstract: Structure and property of glasses and melts: the role of aluminium. The glass is a natural material or made by the human hand, which presents a disordered struc- ture at the atomic scale. Among the main elements of the glasses of oxide, we find Si, Al, Ca and Na. Si and Al form a three-dimensional network of SiO4 and/or AlO − tetrahedra that can be linked, or surroundedby Na or Ca which play various role according to the ratio M/Al (with M = Na/2 or Ca). However the aluminium can play also a more complex role by being in coordinence 5.

Recent Progress in Tunable Cr:ZnS/Se Lasers

Abstract: We report on recent progress in development of high power; high energy; tunable (1.9-3.3 um), mid-IR Cr:ZnS/Se lasers operating in CW (>20 W), gain-switched (>20 mJ@7ns) and long pulse ( >1 J@7ms) regimes.

Thermodynamic mixing properties of Rb-K feldspars

Abstract: Hydrofluoric acid solution calorimetric measurements conducted at 50 °C on a series of Al-Si ordered Rb-K feldspars reveal that the enthalpies Rb-K mixing ( H ex ) for this series are positive, with maximum values skewed toward Rb-rich compositions. However, the magnitudes of H ex are greatly reduced relative to those for Na-K feldspars, as are the positive volumes of Rb-K mixing observed for this series. Both observations can be explained by the substitution of two ions that are relatively similar in size. The difficulty in synthesizing Rb-rich sanidine via Rb-exchange of K-sanidine, contrasted with the ability to synthesize rubicline from K-microcline by such exchange, together with a vanishingly small Δ V between ordered rubicline and disordered Rb-sanidine suggest that the volume of Rb-feldspar is close to the limit to which the feldspar structure can be expanded at 1 bar.