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Personne :
Messaddeq, Younès

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Messaddeq

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Younès

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Université Laval. Département de physique, de génie physique et d'optique

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ncf11860592

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Résultats de recherche

Voici les éléments 1 - 6 sur 6
  • PublicationAccès libre
    Engineering nanoparticle features to tune Rayleigh scattering in nanoparticles-doped optical fibers
    (Springer Nature, 2021-04-27) Fuertes, Victor; Gagnon, Stéphane; Grégoire, Nicolas; Labranche, Philippe; Ledemi, Yannick; LaRochelle, Sophie; Messaddeq, Younès; Wang, Ruohui
    Rayleigh scattering enhanced nanoparticles-doped optical fibers are highly promising for distributed sensing applications, however, the high optical losses induced by that scattering enhancement restrict considerably their sensing distance to few meters. Fabrication of long-range distributed optical fiber sensors based on this technology remains a major challenge in optical fiber community. In this work, it is reported the fabrication of low-loss Ca-based nanoparticles doped silica fibers with tunable Rayleigh scattering for long-range distributed sensing. This is enabled by tailoring nanoparticle features such as particle distribution size, morphology and density in the core of optical fibers through preform and fiber fabrication process. Consequently, fibers with tunable enhanced backscattering in the range 25.9-44.9 dB, with respect to a SMF-28 fiber, are attained along with the lowest two-way optical losses, 0.1-8.7 dB/m, reported so far for Rayleigh scattering enhanced nanoparticles-doped optical fibers. Therefore, the suitability of Ca-based nanoparticles-doped optical fibers for distributed sensing over longer distances, from 5 m to more than 200 m, becomes possible. This study opens a new path for future works in the field of distributed sensing, since these findings may be applied to other nanoparticles-doped optical fibers, allowing the tailoring of nanoparticle properties, which broadens future potential applications of this technology.
  • PublicationAccès libre
    Nonlinear increase, invisibility, and sign inversion of a localized fs-laser-induced refractive index change in crystals and glasses
    (Springer Nature, 2020-04-20) Dupont, Albert; Bérubé, Jean-Philippe; Ledemi, Yannick; Fortin, Vincent; Messaddeq, Younès; Vallée, Réal; Lapointe, Jérôme
    Multiphoton absorption via ultrafast laser focusing is the only technology that allows a three-dimensional structural modification of transparent materials. However, the magnitude of the refractive index change is rather limited, preventing the technology from being a tool of choice for the manufacture of compact photonic integrated circuits. We propose to address this issue by employing a femtosecond-laser-induced electronic band-gap shift (FLIBGS), which has an exponential impact on the refractive index change for propagating wavelengths approaching the material electronic resonance, as predicted by the Kramers–Kronig relations. Supported by theoretical calculations, based on a modified Sellmeier equation, the Tauc law, and waveguide bend loss calculations, we experimentally show that several applications could take advantage of this phenomenon. First, we demonstrate waveguide bends down to a submillimeter radius, which is of great interest for higher-density integration of fs-laser-written quantum and photonic circuits. We also demonstrate that the refractive index contrast can be switched from negative to positive, allowing direct waveguide inscription in crystals. Finally, the effect of the FLIBGS can compensate for the fs-laser-induced negative refractive index change, resulting in a zero refractive index change at specific wavelengths, paving the way for new invisibility applications.
  • PublicationAccès libre
    Co-doped Dy3+ and Pr3+ Ga5Ge20Sb10S65 fibers for mid-infrared broad emission
    (Optical Society of America, 2018-06-13) Ledemi, Yannick; Starecki, Florent; Ari, Julien; Boussard-Plédel, Catherine; Messaddeq, Younès; Doualan, J. L. (Jean Louis); Braud, Alain; Bureau, Bruno; Nazabal, Virginie
    Rare earth ion doped materials are means to obtain cost-effective infrared light sources, with enough brilliance for applications such as gas sensing. Within a sulfide matrix, the simultaneous luminescence of both Pr3+ and Dy3+ in the Ga5Ge20Sb10S65 glass is reported. The use of these two rare earths is giving rise to a broad continuous luminescence in the 2.2–5.5 µm wavelength range, which could be used as a mid-infrared light source for gas-sensing applications. The demonstration of CO2 and CH4 detection using a fiber drawn from these materials is reported.
  • PublicationAccès libre
    Photonic properties of novel Yb3+ doped germanium-lead oxyfluoride glass-ceramics for laser cooling applications
    (Springer, 2018-08-13) Ledemi, Yannick; Thomas, Jyothis; Messaddeq, Younès; Kummara, Venkata Krishnaiah; Seletskiy, Denis V.; Kashyap, Raman; Maïa, Lauro J. Q.
    In recent years, our research group has developed and studied new rare-earth doped materials for the promising technology of solid-state laser cooling, which is based on anti-stokes fluorescence. To the best of our knowledge, our group is the only one in Canada leading the research into the properties of nanoparticles, glasses and glass-ceramics for optical refrigeration applications. In the present work, optical properties of 50GeO2-30PbF2-18PbO-2YbF3 glass-ceramics for laser cooling are presented and discussed as a function of crystallization temperature. Spectroscopic results show that samples have near infrared photoluminescence emission due to the 2F5/2–2F7/2 Yb3+ transition, centered at ~1016 nm with an excitation wavelength of 920 nm or 1011 nm, and the highest photoluminescence emission efficiency occurs for heat-treatment for 5 h at 350°C. The internal photoluminescence quantum yield varies between 99% and 80%, depending on the temperature of heat-treatment, being the most efficient under 1011 nm excitation. The 2F5/2 lifetime increases from 1.472 to 1.970 ms for heat treatments at 330°C to 350°C, respectively, due to energy trapping and the low phonon energy of the nanocrystals. The sample temperature dependence was measured with a fiber Bragg grating sensor, as a function of input pump laser wavelength and processing temperature. These measurements show that the heating process approaches near zero for an excitation wavelength between 1020 and 1030 nm, which is an indication that phonons are removed effectivelly from the glass-ceramic materials, and they can be used for optical laser cooling applications. On the other hand, the temperature increase as a function of input laser power into samples remains constant between 920 and 980 nm wavelength excitation, a temperature variation of 36 K/W (temperature of 58°C/W) was attained under excitation at 950 nm, showing a possible use for biomedical applications to be explored.1)
  • PublicationAccès libre
    Structure and properties of gallium-rich sodium germano-gallate glasses
    (American Chemical Society, 2018-12-10) Ledemi, Yannick; Kroeker, Scott; Skopak, Tea; Levin, Karen S.; Messaddeq, Younès; Dussauze, Marc; Méreau, Raphael; Cardinal, Thierry; Fargin, Evelyne
    Glass compositions in the gallium-rich region of the ternary GaO3/2–GeO2–NaO1/2 vitreous system are studied as a function of the Na/Ga cationic ratio (ranging from 1.30 to 1.61) for a fixed GeO2 content. Glass structures are investigated by 71Ga magic angle spinning nuclear magnetic resonance, infrared, and Raman spectroscopies, and the thermal, optical, and physical properties are characterized. Vibrational spectra are interpreted with the help of density functional theory calculations. Gallium oxide generally enters the germania network in fourfold coordination, however, for a Na/Ga ratio below unity, gallium cations tend to charge balance with the formation of five- or six-fold coordination units. When the amount of sodium is greater than gallium, nonbridging oxygens are formed preferably on germanate tetrahedral units. These structural descriptions are used to understand the evolution of glass properties such as glass transition temperature, density, and refractive index.
  • PublicationAccès libre
    Tunable distributed sensing performance in Ca-based nanoparticle-doped optical fibers
    (OSA Pub., 2022-03-04) Gagnon, Stéphane; Grégoire, Nicolas; Morency, Steeve; Ledemi, Yannick; Fuertes, Victor; LaRochelle, Sophie; Messaddeq, Younès
    Rayleigh scattering enhanced nanoparticle-doped optical fibers is a technology very promising for distributed sensing applications, however, it remains largely unexplored. This work demonstrates for the first time the possibility of tuning Rayleigh scattering and optical losses in Ca-based nanoparticle-doped silica optical fibers by controlling the kinetics of the re-nucleation process that nanoparticles undergo during fiber drawing by controlling preform feed, drawing speed and temperature. A 3D study by SEM, FIB-SEM and optical backscatter reflectometry (OBR) reveals an early-time kinetics at 1870 °C, with tunable Rayleigh scattering enhancement 43.2–47.4 dB, regarding a long-haul single mode fiber, SMF-28, and associated sensing lengths of 3–5.5 m. At 2065 °C, kinetics is slower and nanoparticle dissolution is favored. Consequently, enhanced scattering values of 24.9–26.9 dB/m and sensing lengths of 135–250 m are attained. Finally, thermal stability above 500 °C and tunable distributed temperature sensitivity are proved, from 18.6 pm/°C to 23.9 pm/°C, ∼1.9–2.4 times larger than in a SMF-28. These results show the promising future of Rayleigh scattering enhanced nanoparticle-doped optical fibers for distributed sensing.