References of "Dreesen, Laurent"
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See detailStudy of the water/poly(ethylene glycol) interface by IR-visible sum-frequency generation spectroscopy
Dreesen, Laurent ULg; Humbert, C.; Hollander, P. et al

in Chemical Physics Letters (2001), 333

We used infrared-visible sum-frequency generation spectroscopy to investigate the vibrational properties of the water/poly(ethylene glycol) interface in the 2800-3800 cm-1 spectral range. The vibrational ... [more ▼]

We used infrared-visible sum-frequency generation spectroscopy to investigate the vibrational properties of the water/poly(ethylene glycol) interface in the 2800-3800 cm-1 spectral range. The vibrational fingerprint of the interface differs significantly from the one associated with the aire/poly(ethylene glycol) interface. It is shown that the poly(ethylene glycol) molecular arrangement, originally relatively well-ordered, becomes disorganised in the presence of water. Moreover, a new OH band is identified demonstrating the strong interaction of water with the polymer. [less ▲]

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See detailPumping picosecond optical parametric oscillators by a pulsed Nd:YAG laser mode locked using a nonlinear mirror
Mani, A. A.; Dreesen, Laurent ULg; Hollander, Ph. et al

in Applied Physics Letters (2001), 79(13), 1945-1947

We report on the performances of the mode locking of a flash-lamp-pumped Nd:YAG laser using a frequency-doubling nonlinear mirror combined with a two-photon absorber. Pulse lengths from 12 to 8 ps are ... [more ▼]

We report on the performances of the mode locking of a flash-lamp-pumped Nd:YAG laser using a frequency-doubling nonlinear mirror combined with a two-photon absorber. Pulse lengths from 12 to 8 ps are generated. We show that the flat shape of the pulse-train envelope generated by the oscillator is adapted for the synchronous pumping of optical parametric oscillators and we demonstrate the efficient generation of an infrared beam tunable from 3800 to 1100 cm-1 with bandwidth of 2 cm-1 in one single conversion stage in LiNbO3 or AgGaS2. The "all-solid-state" laser system enables surface sum-frequency generation spectroscopy to be performed with high sensitivity and high resolution. [less ▲]

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See detailSum-frequency generation characterisation of methanol, pentadecanoïc acid and water interfaces
Humbert, Christophe; Dreesen, Laurent ULg; Hollander, Philippe et al

Poster (2000, May)

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See detailSum-frequency generation characterisation of methanol-calcium fluoride and water-calcium fluoride interfaces
Dreesen, Laurent ULg; Humbert, Christophe; Hollander, Philippe et al

Poster (2000, April 03)

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See detailDevelopment of an all-solid-state pulsed Nd:YAG laser for pumping picosecond OPO systems
Mani, A. A.; Dreesen, Laurent ULg; Hollander, Ph. et al

in Proceedings (1999)

High performance mode-locking of a pulsed Nd:YAG laser was achieved at 1.064 µm by using a frequency doubling nonlinear mirror (FDNLM) based on a BBO crystal for second harmonic generation and on a ... [more ▼]

High performance mode-locking of a pulsed Nd:YAG laser was achieved at 1.064 µm by using a frequency doubling nonlinear mirror (FDNLM) based on a BBO crystal for second harmonic generation and on a dichroïc mirror. A GaAs platelet was inserted into the laser cavity for providing a passive negative feedback. Pulses shorter than 15 ps were generated. The FDNLM has the following merits: photochemical stability, short response time, simplicity and applicability to a wide spectral range. The optical oscillator is the first element of a two-color laser system including two synchronously pumped optical parametric oscillators (OPO) built around a BBO and a LiNbO3 crystal, and tunable from 410 to 2600 nm and from 2.5 to 3.6 µm, respectively. [less ▲]

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See detailGrazing incidence X-ray reflectometry studies of CdTe(1 1 1) surfaces and a-Si thin films
Ijdiyaou, I.; Hafidi, K.; Azizan, M. et al

in Solar Energy Materials & Solar Cells (1998), 52

Chemically treated cadmium telluride (CdTe) surfaces and amorphous silicon (a-Si) thin films were characterized by X-ray reflectometry at grazing incidence. In the case of the surface of CdTe single ... [more ▼]

Chemically treated cadmium telluride (CdTe) surfaces and amorphous silicon (a-Si) thin films were characterized by X-ray reflectometry at grazing incidence. In the case of the surface of CdTe single crystal treated with an oxidizing agent (a solution of Br2 in CH3OH), the superficial layer was found to be less dense than its support with a profound alteration of CdTe in the volume. After rinsing in KOH solution, the properties of single-crystalline CdTe are obtained. In the case of a-Si thin layers, we show that the simulation of the reflectometry curves enables not only the determination of the layer thickness but also the detection of an ultrathin superficial oxide layer. [less ▲]

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See detailCharacterization of CuInTe2 thin films prepared by flash evaporation
Boustani, M.; El Assali, K.; Bekkay, T. et al

in Semiconductor Science & Technology (1997), 12

Thin films of CuInTe2 were grown by flash evaporation. The influence of the substrate temperature Ts during film deposition on the properties of the thin films was examined. CuInTe2 films were ... [more ▼]

Thin films of CuInTe2 were grown by flash evaporation. The influence of the substrate temperature Ts during film deposition on the properties of the thin films was examined. CuInTe2 films were structurally characterized by the grazing incidence x-ray diffraction (GIXD) technique. Investigation by this technique demonstrates that the surface of thin films of CuInTe2 prepared by flash vaporation at Ts > 100 °C exhibits the chalcopyrite structure with additional binary compounds in the surface. However, in the volume the films exhibit the chalcopyrite structure only; no foreign phases were observed. X-ray reflectometry was utilized to evaluate the critical reflection angle bc of CuInTe2 (bCuInTe2 c 0.32°) which permitted us to calculate the density of the films to be 6 g cm−3. The evaporated films were p type and the films deposited at Ts = 100 °C had a resistivity in the range 0.3–2 cm. From optical measurements we have determined the optical energy gap Eg 0.94 eV and the effective reduced mass m*r 0.07me . [less ▲]

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See detailEtude des propriétés électriques des hétérojonctions de semi-conducteurs II-VI
Dreesen, Laurent ULg

Master's dissertation (1990)

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