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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 - 10 sur 40
  • PublicationAccès libre
    Templated dewetting for self-assembled ultra low-loss chalcogenide integrated photonics
    (OSA Pub., 2021-10-11) Jean, Philippe; LaRochelle, Sophie; Shi, Wei; Messaddeq, Younès; Douaud, Alexandre
    Integrated photonics is of growing interest but relies on complex fabrication methods that have yet to match optical losses of bulkier platforms like optical fibers or whispering gallery mode resonators. Spontaneous matter reorganization phenomenon (e.g. dewetting) in thin-films provides a way for self-assembled structures with atomic scale surface rugosity, potentially alleviating the problems of roughness scattering loss and fabrication complexity. In this article, we study solid-state dewetting in chalcogenide glass thin-films and demonstrate its applicability to the fabrication of high-quality integrated photonics components. Optimal dewetting parameters are derived from a comprehensive experimental study of thin-film properties under high temperature rapid annealing. Atomic scale surface roughness are obtained using dewetting, with RMS values as low as Rq = 0.189 nm. Several integrated photonics components are fabricated using the method and characterized. We show that the use of pre-patterned templates leads to organized, reproducible patterns with large-scale uniformity and demonstrate the record high quality-factor of 4.7 × 106 in compact (R = 50 µm) microdisks, corresponding to 0.08 dB⋅cm−1 waveguide propagation loss. The integrated devices are directly fabricated on standard silicon-on-insulator dice using the micro-trench filling technique and coupled to silicon waveguides, making them readily deployable with existing silicon devices and systems.
  • PublicationAccès libre
    Atomic level structure of Ge-Sb-S glasses : chemical short range order and long Sb-S bonds
    (Elsevier Science, 2018-09-28) Pethes, Ildikó; Ari, Julien; Nazabal, Virginie; Messaddeq, Younès; Kaban, Ivan; Darpentigny, Jacques; Welter, Edmund; Gutowski, Olof; Bureau, Bruno; Jóvári, Pál
    The structure of Ge20Sb10S70, Ge23Sb12S65 and Ge26Sb13S61 glasses was investigated by neutron diffraction (ND), X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS) measurements at the Ge and Sb K-edges as well as Raman scattering. For each composition, large scale structural models were obtained by fitting simultaneously diffraction and EXAFS data sets in the framework of the reverse Monte Carlo (RMC) simulation technique. Ge and S atoms have 4 and 2 nearest neighbors, respectively. The structure of these glasses can be described by the chemically ordered network model: Ge-S and Sb-S bonds are always preferred. These two bond types adequately describe the structure of the stoichiometric glass while S-S bonds can also be found in the S-rich composition. Raman scattering data show the presence of Ge-Ge, Ge-Sb and Sb-Sb bonds in the S-deficient glass but only Ge-Sb bonds are needed to fit diffraction and EXAFS datasets. A significant part of the Sb-S pairs has 0.3–0.4 Å longer bond distance than the usually accepted covalent bond length (∼2.45 Å). From this observation it was inferred that a part of Sb atoms have more than 3 S neighbors.
  • 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
    Perfect vortex modes for nondestructive characterization of mode dependent loss in ring core fibers
    (New York, N.Y. : Institute of Electrical and Electronics Engineers, 2022-08-02) Banawan, Mai; Mishra, Satyendra K.; Messaddeq, Younès; LaRochelle, Sophie; Rusch, Leslie
    Ring core fibers (RCF) enable high-performance modal multiplexing with low crosstalk and can support orbital angular momentum (OAM) modes. RCFs are challenging to characterize due to the lack of commercial multiplexers, especially for high OAM orders. For fibers supporting large numbers of modes, typical cutback techniques for characterization are extremely wasteful of fiber, especially as one cutback is required for each mode. We show the differential modal loss across modes 3 to 10 was significantly underestimated using an OTDR when exciting modes individually or when exciting all modes indiscriminately. We exploit perfect vortex beams to achieve reliable and nondestructive characterization of mode-dependent loss (MDL) for OAM modes. Perfect vortex beams allow us to maximize the coupling efficiency at each mode launch, increasing the accuracy of MDL estimate. We fabricated fiber with a refractive index difference between the ring core and the cladding of a 5.1×10⁻². For this fiber, mode orders 3 to 10 are the most suitable for data transmission and were the focus of our work (the fiber support up to OAM order 13). Such a high index difference can lead to MDL. We demonstrate that the modal loss spans from 2.14 to 4.38 dB/km for orders 3 to 10.
  • PublicationAccès libre
    Femtosecond self-reconfiguration of laser-induced plasma patterns in dielectrics
    (American Physical Society, 2018-05-11) Messaddeq, Sandra Helena; Varin, Charles; Déziel, Jean-Luc; Dubé, Louis J.; Messaddeq, Younès
    Laser-induced modification of transparent solids by intense femtosecond laser pulses allows fast integration of nanophotonic and nanofluidic devices with controlled optical properties. Experimental observations suggest that the local and dynamic nature of the interactions between light and the transient plasma plays an important role during fabrication. Current analytical models neglect these aspects and offer limited coverage of nanograting formation on dielectric surfaces. In this paper, we present a self-consistent dynamic treatment of the plasma buildup and its interaction with light within a three-dimensional electromagnetic framework. The main finding of this work is that local light-plasma interactions are responsible for the reorientation of laser-induced periodic plasma patterns with respect to the incident light polarization, when a certain energy density threshold is reached. Plasma reconfiguration occurs within a single laser pulse, on a femtosecond time scale. Moreover, we show that the reconfigured subwavelength plasma structures actually grow into the bulk of the sample, which agrees with the experimental observations of self-organized volume nanogratings. We find that mode coupling of the incident and transversely scattered light with the periodic plasma structures is sufficient to initiate the growth and self-organization of the pattern inside the medium with a characteristic half-wavelength periodicity.
  • PublicationAccès libre
    Sulfur-rich chalcogenide claddings for athermal and high-Q silicon microring resonators
    (OSA Pub., 2021-02-26) Jean, Philippe; LaRochelle, Sophie; Thibault, Tristan; Shi, Wei; Messaddeq, Younès; Douaud, Alexandre
    Heterogeneous integration of materials with a negative thermo-optic coefficient is a simple and efficient way to compensate the strong detrimental thermal dependence of silicon-on-insulator devices. Yet, the list of materials that are both amenable for photonics fabrication and exhibit a negative TOC is very short and often requires sacrificing loss performance. In this work, we demonstrate that As20S80 chalcogenide glass thin-films can be used to compensate silicon thermal effects in microring resonators while retaining excellent loss figures. We present an experimental characterization of the glass thin-film and of fabricated hybrid microring resonators at telecommunication wavelengths. Nearly athermal operation is demonstrated for the TM polarization with an absolute minimum measured resonance shift of 5.25 pm K−1, corresponding to a waveguide effective index thermal dependence of 4.28×10-6 RIU/K. We show that the thermal dependence can be controlled by changing the cladding thickness and a negative thermal dependence is obtained for the TM polarization. All configurations exhibit unprecedented low loss figures with a maximum measured intrinsic quality factor exceeding 3.9 × 105, corresponding to waveguide propagation loss of 1.37 dB cm−1. A value of−4.75(75)×10-5 RIU/K is measured for the thermo-optic coefficient of As20S80 thin-films.
  • PublicationRestreint
    Baria-silica erbium-doped fibers for extended L-band amplification
    (Institute of Electrical and Electronics Engineers, 2023-02-13) Jalilpiran, Saber; Fuertes, Victor; Lefebvre, Jacques; Grégoire, Nicolas; Durak, Firat; Landry, Nelson; Wang, Lixian; Rivera, V. A. G; Messaddeq, Younès; LaRochelle, Sophie
    We present baria-silica erbium-doped fibers (BaEDF) for extending the bandwidth of L-band EDFAs beyond 1620 nm. Using a combination of modified chemical vapor deposition (MCVD) process and solution-doping technique, we demonstrate low loss (<10 dB/km at 1200 nm) fiber cores with BaO concentration of 1-3 mol% and Er3+ concentration of 8×1024 m-3 . We show that the optical properties and EDFA performance are positively affected by increasing the BaO content. Namely, when we increase the BaO concentration from 1.3 to 3 mol%, we observe a reduction of pair-induced quenching that correlates with a biexponential luminescence decay with a dominant 15.5 ms lifetime component. Furthermore, the slight modifications of absorption/ emission coefficients point to a red-shift of the signal excited state absorption and consequently, to a moderate extension of the L-band gain to longer wavelengths (1622 nm).
  • PublicationAccès libre
    Analysis of inter-core cross-gain modulation in cladding pumped multi-core fiber amplifiers
    (IEEE Xplore, 2018-11-15) Essiambre, René-Jean.; Chen, Haoshuo; Matte-Breton, Charles; Fontaine, Nicolas K.; LaRochelle, Sophie; Ryf, Roland; Messaddeq, Younès
    We numerically investigate pump-induced gain variations in eight-core fi ber amplifi ers. We compare two fi bers with different erbium profi les by varying input power from -25 dBm to 0 dBm in one or four cores. Inter-core cross-gain modulation is < 0.6 dB.
  • PublicationAccès libre
    The EcoChip : a wireless multi-sensor platform for comprehensive environmental monitoring
    (IEEE, 2018-10-31) Tremblay, Denise; Gosselin, Benoit; Morency, Steeve; Faucher, Félix; Sarrazin, Denis; Moineau, Sylvain; Corbeil, Jacques; Sylvain, Matthieu; Messaddeq, Younès; Allard, Michel; Lehoux, Francis; Bharucha, Eric; Raymond, Frédéric
    This paper presents the EcoChip, a new system based on state-of-the-art electro-chemical impedance (EIS) technologies allowing the growth of single strain organisms isolated from northern habitats. This portable system is a complete and autonomous wireless platform designed to monitor and cultivate microorganisms directly sampled from their natural environment, particularly from harsh northern environments. Using 96-well plates, the EcoChip can be used in the field for realtime monitoring of bacterial growth. Manufactured with highquality electronic components, this new EIS monitoring system is designed to function at a low excitation voltage signal to avoid damaging the cultured cells. The high-precision calibration network leads to high-precision results, even in the most limiting contexts. Luminosity, humidity and temperature can also be monitored with the addition of appropriate sensors. Access to robust data storage systems and power supplies is an obvious limitation for northern research. That is why the EcoChip is equipped with a flash memory that can store data over long periods of time. To resolve the power issue, a low-power microcontroller and a power management unit control and supply all electronic building blocks. Data stored in the EcoChip’s flash memory can be transmitted through a transceiver whenever a receiver is located within the functional transmission range. In this paper, we present the measured performance of the system, along with results from laboratory tests in-vitro and from two field tests. The EcoChip has been utilized to collect bio-environemental data in the field from the northern soils and ecosystems of Kuujjuarapik and Puvirnituq, during two expeditions, in 2017 and 2018, respectively. We show that the EcoChip can effectively carry out EIS analyses over an excitation frequency ranging from 750 Hz to 10 kHz with an accuracy of 2.35%. The overall power consumption of the system was 140.4 mW in normal operating mode and 81 µW in sleep mode. The proper development of the isolated bacteria was confirmed through DNA sequencing, indicating that bacteria thrive in the EcoChip’s culture wells while the growing conditions are successfully gathered and stored.