Abdelmajid Salhi

Publications (2)4.2 Total impact

• Source

  Available from: Johannes Koeth

  Article: Novel Helmholtz-based photoacoustic sensor for trace gas detection at ppm level using GaInAsSb/GaAlAsSb DFB lasers.

  Mario Mattiello, Marc Niklès, Stéphane Schilt, Luc Thévenaz, Abdelmajid Salhi, David Barat, Aurore Vicet, Yves Rouillard, Ralph Werner, Johannes Koeth
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  ABSTRACT: A new and compact photoacoustic sensor for trace gas detection in the 2-2.5 microm atmospheric window is reported. Both the development of antimonide-based DFB lasers with singlemode emission in this spectral range and a novel design of photoacoustic cell adapted to the characteristics of these lasers are discussed. The laser fabrication was made in two steps. The structure was firstly grown by molecular beam epitaxy then a metallic DFB grating was processed. The photoacoustic cell is based on a Helmholtz resonator that was designed in order to fully benefit from the highly divergent emission of the antimonide laser. An optimized modulation scheme based on wavelength modulation of the laser source combined with second harmonic detection has been implemented for efficient suppression of wall noise. Using a 2211 nm laser, sub-ppm detection limit has been demonstrated for ammonia.
  Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 05/2006; 63(5):952-8. · 2.10 Impact Factor
• Source

  Available from: Johannes Koeth

  Article: Application of antimonide diode lasers in photoacoustic spectroscopy.

  Stéphane Schilt, Aurore Vicet, Ralph Werner, Mario Mattiello, Luc Thévenaz, Abdelmajid Salhi, Yves Rouillard, Johannes Koeth
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  ABSTRACT: First investigations of photoacoustic (PA) spectroscopy (PAS) of methane using an antimonide semiconductor laser are reported. The laser fabrication is made in two steps. The structure is firstly grown by molecular beam epitaxy, then a metallic distributed-feedback (DFB) grating is processed. The laser operates at 2371.6 nm in continuous wave and at room temperature. It demonstrates single-mode emission with typical tuning coefficients of 0.04 nm mA(-1) and 0.2 nm K(-1). PA detection of methane was performed by coupling this laser into a radial PA cell. A detection limit of 20 ppm has been achieved in a preliminary configuration that was not optimised for the laser characteristics.
  Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 01/2005; 60(14):3431-6. · 2.10 Impact Factor