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Hendaoui N.,University of Namur | Hendaoui N.,Advanced Technologies Development Center | Peremans A.,University of Namur | Schunemann P.G.,BAE Systems | And 2 more authors.
Laser Physics | Year: 2013

We compare the performance of two different mid-infrared nonlinear crystals, type I and type II AgGaS2 (AGS), and type I CdSiP 2 (CSP), in a synchronously pumped optical parametric oscillator (SPOPO) pumped at 1064 nm. CSP showed a clear performance advantage at 6.5 μm idler wavelength in comparison to AGS. The oscillation threshold with CSP was three and five times lower compared to AGS type II and type I, respectively. The highest quantum conversion efficiency was obtained for CSP. It allowed us to reach 27.5 mW of idler average power, compared to 13 and 6 mW with type II and type I AGS, respectively. However, the tuning range was narrower with CSP than with AGS in both type I and type II configurations. The performance of the CSP SPOPO makes it suitable for generation of high power picosecond pulses at 6.45 μm for surgical applications. © 2013 Astro Ltd. Source


Amara E.H.,Advanced Technologies Development Center
Lasers in Engineering | Year: 2011

Deep penetration laser welding is studied at processing speeds leading to the humping phenomenon. Matter melting, vaporization and re-solidification are considered through the implementation of user-defined functions (UDFs) used with a commercial computational fluid dynamics (CFD) Fluent code. The dynamic mesh method implementation allowed us to simulate regular hump formation. © 2011 Old City Publishing, Inc. Source


Bitchikh M.,Advanced Technologies Development Center | Azrar A.,University of Boumerdes | Aksas R.,Polytechnic School of Algiers
Wireless Personal Communications | Year: 2016

This paper concerns the design of a new ultra-wideband antenna with an octagonal configuration and reduced size. The prototype has been simulated and designed. It has shown a permissible agreement between simulations and measures and an operation of ultra-wideband from 2.38 to 14 GHz (142 %) for wireless applications. © 2015, Springer Science+Business Media New York. Source


Hamadi F.,Advanced Technologies Development Center | Amara E.H.,Advanced Technologies Development Center
Advanced Materials Research | Year: 2011

In this paper we present a numerical modeling of a nanosecond laser pulse interaction with a titanium target. We investigate the vapor plume formation and the influence of the ambient gas pressure on plume expansion dynamics. The vapor plume formation depends on the results of the heat transfer in the solid target modeling. The solid-liquid phase change is modeled by a two dimensional approach using an enthalpy formulation. The resulting plume expansion in the argon background gas is studied using the species transport model. The algebraic equations are discretized by the finite volume method implemented by Fluent CFD software [1]. The calculation results of plume expansion velocity, density, temperature and degree of ionization in the plume are presented. © (2011) Trans Tech Publications. Source


Tamsaout T.,Advanced Technologies Development Center | Amara E.H.,Advanced Technologies Development Center
Advanced Materials Research | Year: 2011

Laser forming is a technique consisting in the design and the construction of complex metallic work pieces with special shapes difficult to achieve with the conventional techniques. By using lasers, the main advantage of the process is that it is contactless and does not require any external force. It offers also more flexibility for a lower price. This kind of processing interests the industries that use the stamping or other costly ways for prototypes such as in the aero-spatial, automotive, naval and microelectronics industries. The analytical modeling of laser forming process is often complex or impossible to achieve, since the dimensions and the mechanical properties change with the time and in the space. Therefore, the numerical approach is more suitable for laser forming modeling. Our numerical study is divided into two models, the first one is a purely thermal treatment which allows the determination of the temperature field produced by a laser pass, and the second one consists in the thermo-mechanical coupling treatment. The temperature field resulting from the first stage is used to calculate the stress field, the deformations and the bending angle of the plate. © (2011) Trans Tech Publications. Source

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