Personne :
Messaddeq, Younès

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Structures organisationnelles
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Université Laval. Département de physique, de génie physique et d'optique
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Voici les éléments 1 - 10 sur 10
  • Publication
    Accès 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.
  • Publication
    Accès libre
    Multimodal structural characterization of Ge−S−I glasses by combination of DFT calculation and IR and polarized Raman Spectroscopy
    (American Chemical Society, 2019-01-14) Chazot, Matthieu; Méreau, Raphaël; El Amraoui, Mohammed; Messaddeq, Younès; Adamietz, Frédéric; Rodriguez, Vincent
    From a dual experimental–theoretical vibrational analysis, we propose a new rationalized structural description of Ge–S–I chalcogenides glasses at the nanoscale. A vibrational multipolar approach based on a simultaneous deconvolution of infrared (IR) and polarized Raman spectra (RS-VV and RS-HV) has been applied on these glasses. According to recent results on the amorphous GeS2 structure by X-Ray and neutron diffraction and to our spectral analyses, we suggest that the local structure of the glass backbone is effectively described by a combination of α-GeS2 nanolayers, edge-sharing GeS4 tetrahedra (ES-Td, ca ∼50%), and corner-sharing GeS4 tetrahedra (CS-Td, ca ∼50%). We have then compared the experimental spectra to the calculated IR and polarized Raman spectra of some selected GexSyIz structural units obtained by density functional theory calculation. The stretching modes of the Ge–S–I occurring in the high frequency spectral range (300–450 cm–1) are essentially those of the GeS2 glass backbone and have been revisited. In addition, through a careful analysis of the vibrational multipolar activities of stoichiometric and over-stoichiometric sulfur glasses between 180 and 280 cm–1, we propose new assignments for the seven modes that have been identified by our trimodal spectral analysis. We finally suggest that there is a competition between the insertion of atomic iodine as a glass modifier which involves the Ge–S–I clusters and molecular diiodine as a spectator encaged between two α-GeS2 nanolayers.
  • Publication
    Accès libre
    Mode division multiplexing using orbital angular momentum modes over 1.4 km ring core fiber
    (Institute of Electrical and Electronics Engineers, 2016-07-27) Mirzaei Nejad, Reza; Amiralizadeh, Siamak; Brunet, Charles; LaRochelle, Sophie; Messaddeq, Younès; Allahverdyan, Karen; Rusch, Leslie; Vaity, Pravin
    Mode division multiplexing (MDM) systems using orbital angular momentum (OAM) modes can recover the data in D different modes without recourse to full (2D × 2D) multiple input multiple output (MIMO) processing. One of the biggest challenges in OAM-MDM systems is the mode instability following fiber propagation. Previously, MIMO-free OAM-MDM data transmission with two modes over 1.1 km of vortex fiber was demonstrated, where optical polarization demultiplexing was employed in the setup. We demonstrate MDM data transmission using two OAM modes over 1.4 km of a specially designed ring core fiber without using full MIMO processing or optical polarization demultiplexing. We demonstrate reception with electrical polarization demultiplexing, i.e., minimal 2 × 2 MIMO, showing the compatibility of OAM-MDM with current polarization demultiplexing receivers.
  • Publication
    Accès libre
    Orbital-angular-momentum polarization mode dispersion in optical fibers
    (Institute of Electrical and Electronics Engineers, 2016-04-15) LaRochelle, Sophie; Messaddeq, Younès; Chatigny, Stephane; Wang, Lixian; Rusch, Leslie; Vaity, Pravin
    The orbital-angular-momentum (OAM) modes in optical fibers have polarization mode dispersion (PMD) properties similar to those of single-mode fibers (SMFs). The +l and -l order OAM modes supported by the same fiber vector modes undergo random cross coupling and exhibit a frequency-dependent time delay. We name this effect “OAM-PMD” and extend the formalism developed for PMD in SMFs to describe OAM-PMD. The characteristics of the modal beat lengths, birefringence correlation lengths, and the mean value of OAM-PMD are investigated. A fixed-analyzer technique is proposed and demonstrated to characterize this phenomenon in OAM fibers. Two different types of OAM fiber are examined. The measured results are compared with the theoretical calculations.
  • Publication
    Accès 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.
  • Publication
    Accès libre
    Modeling and characterization of cladding-pumped erbium-ytterbium co-doped fibers for amplification in communication systems
    (Institute of Electrical and Electronics Engineers, 2019-12-20) Essiambre, René-Jean.; Ryf, Roland; Matte-Breton, Charles; Fontaine, Nicolas K.; LaRochelle, Sophie; Messaddeq, Younès; Chen, Haoshuo; Kelly, C.
    Cladding-pumped optical fiber amplifiers are of increased interest in the context of space-division multiplexing but are known to suffer from low power efficiency. In this context, ytterbium (Yb) co-doping can be an attractive solution to improve the performance of erbium (Er) doped fiber amplifiers. We present a detailed direct comparison between Er/Yb-co-doping and Er-doping using numerical simulations validated by experimental results. Two double-cladding fibers, one doped with Er only and the other one co-doped with Er and Yb, were designed, fabricated and characterized. Using the experimentally extracted parameters, we simulate multi-core fiber amplifiers and investigate the interest of Er/Yb-co-doping. We calculate the minimum gain of the amplifiers over a 35-nm spectral window considering various scenarios.
  • Publication
    Accès libre
    Demonstration of an erbium-doped fiber with annular doping for low gain compression in cladding-pumped amplifiers
    (The Optical Society, 2018-10-01) Essiambre, René-Jean.; Chen, Haoshuo; Matte-Breton, Charles; Fontaine, Nicolas K.; Jin, Cang; Ryf, Roland; LaRochelle, Sophie; Messaddeq, Younès; Kelly, C.
    We present the design and characterization of a cladding-pumped amplifier with erbium doping located in an annular region near the core. This erbium-doped fiber is proposed to reduce gain saturation, leading to smaller gain compression when compared to uniform core doping. Through numerical simulations, we first compare the performance of three fibers with different erbium doping profiles in the core or the cladding. When the doped fibers are operated at the optimum length, results show that the smaller overlap of the signal mode field with the annular erbium doping region leads to higher gain and lower saturation of the amplifier. A single-core erbium-doped fiber with an annular doping and a D-shaped cladding was fabricated. Measurements demonstrate less than 4 dB of gain compression over the C-band for input power ranging from −40 dBm to 3 dBm. Small gain compression EDFAs are of interest for applications that require input channel reconfiguration. Higher gain and saturation output power are also key issues in cladding-pumped multi-core amplifiers.
  • Publication
    Accès libre
    Integrated cladding-pumped multicore few-mode erbium-doped fibre amplifier for space-division-multiplexed communications
    (Nature Pub. Group, 2016-07-11) Chen, Haoshuo; Essiambre, René-Jean.; Grégoire, Nicolas; Huang, Bin; Morency, Steeve; Fontaine, Nicolas K.; Jin, Cang; Ryf, Roland; LaRochelle, Sophie; Shang, Kuanping; Messaddeq, Younès; Li, Guifang
    Space-division multiplexing (SDM), whereby multiple spatial channels in multimode1 and multicore2 optical fibres are used to increase the total transmission capacity per fibre, is being investigated to avert a data capacity crunch3,4 and reduce the cost per transmitted bit. With the number of channels employed in SDM transmission experiments continuing to rise, there is a requirement for integrated SDM components that are scalable. Here, we demonstrate a cladding-pumped SDM erbium-doped fibre amplifier (EDFA) that consists of six uncoupled multimode erbium-doped cores. Each core supports three spatial modes, which enables the EDFA to amplify a total of 18 spatial channels (six cores × three modes) simultaneously with a single pump diode and a complexity similar to a single-mode EDFA. The amplifier delivers >20 dBm total output power per core and <7 dB noise figure over the C-band. This cladding-pumped EDFA enables combined space-division and wavelength-division multiplexed transmission over multiple multimode fibre spans.
  • Publication
    Accès libre
    Investigation of C-band pumping for extended L-band EDFAs
    (Optical Society of America, 2020-07-15) Lei, Chengmin; LaRochelle, Sophie; Feng, Hanlin; Messaddeq, Younès
    In this study, we present systematic numerical and experimental analysis of high-power C-band light pumping in extended L-band EDFAs. We investigate, for the first time to our best knowledge, how C-band light sources can be used as pump sources to extend the bandwidth of L-band EDFAs beyond 1610 nm. Results show that, when using a C-band light source as the sole pump, efficient amplification is obtained over the extended L-band but at the expense of higher noise figure. However, the advantage of C-band pumping in terms of power conversion efficiency can be exploited when using a two-stage EDFA, with a first stage pumped by 1480 nm to maintain good noise figure performance and a high-power C-band light source (up to several hundred mW) as the pump source for the second stage. Thus, a 20-dB gain covering 1570-1618 nm with a maximum noise figure of 5.7 dB is demonstrated.
  • Publication
    Accès 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.