A5087735093- Photonic Crystal and Fiber Optics
- Advanced Fiber Optic Sensors
- Advanced Fiber Laser Technologies
- Solid State Laser Technologies
- Glass properties and applications
- Optical Network Technologies
- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Irish and British Studies
- Historical Studies and Socio-cultural Analysis
- Luminescence Properties of Advanced Materials
- Advanced Photonic Communication Systems
- Advanced Optical Sensing Technologies
- ZnO doping and properties
- Radiation Detection and Scintillator Technologies
- French Historical and Cultural Studies
- Laser-Matter Interactions and Applications
- Advanced Radiotherapy Techniques
- Maternal and Perinatal Health Interventions
- Laser Design and Applications
- Political and Social Issues
- Maternal Mental Health During Pregnancy and Postpartum
- Assisted Reproductive Technology and Twin Pregnancy
- Photorefractive and Nonlinear Optics
- Gas Sensing Nanomaterials and Sensors
Centre Hospitalier Lannion Trestel
2024-2025
Photonics Bretagne (France)
2015-2024
Centre National de la Recherche Scientifique
2024
Laboratoire Hubert Curien
2024
Laboratoire de Physique Corpusculaire de Caen
2024
Institut d’Optique Graduate School
2024
iXBlue (France)
2015-2023
Université d'Orléans
2009-2023
Réceptions et médiations de littératures et de cultures étrangères et comparées
2023
Leibniz Institute of Photonic Technology
2021
Silica-based optical fibers, fiber-based devices and fiber sensors are today integrated in a variety of harsh environments associated with radiation constraints. Under irradiation, the macroscopic properties fibers modified through three main basic mechanisms: induced attenuation, emission refractive index change. Depending on profile use, these phenomena differently contribute to degradation performances then have be either mitigated for tolerant systems or exploited design detectors...
In this topical review, the recent progress on radiation-hardened fiber-based technologies is detailed, focusing examples for space applications. first part of we introduce operational principles various considered use in radiation environments: passive optical fibers data links, diagnostics, active amplifiers and laser sources as well different classes point distributed fiber sensors: gyroscopes, Bragg gratings, Rayleigh, Raman or Brillouin-based sensors. Second, describe state art...
We report the results of several complementary radiation tests to qualify and calibrate a highly sensitive Single-Mode (SM) Optical Fiber (OF) for distributed dosimetry application at CERN. The Radiation Induced Attenuation (RIA) is physical phenomenon used evaluate Total Ionizing Dose (TID) received by OF sensor. response comprise online RIA in Near InfraRed (NIR) domain under <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sup> Co γ-rays,...
We investigated the efficiencies of two different approaches to increase radiation hardness optical amplifiers through development improved rare-earth (RE) doped fibers. demonstrated efficiency codoping with Cerium core Erbium/Ytterbium fibers improve their tolerance. compared γ-rays induced degradation comparable pre-irradiation characteristics (~19 dB gain for an input power ~10 dBm): first one is made standard composition whereas second Ce codoped. The tolerance Ce-codoped fiber based...
We present a new structure for erbium-doped optical fibers [hole-assisted carbon-coated, (HACC)] that, combined with an appropriate choice of codopants in the core, strongly enhances their radiation tolerance. built fiber amplifier based on this HACC and characterize its degradation under γ-ray doses up to 315 krad (SiO2) ON mode. The 31 dB is practically insensitive, gain change merely -2.2×10(-3) dB/krad. These performances authorize use doped amplifiers various applications environments...
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We characterize by different spectroscopic techniques the radiation effects on ytterbium- (Yb) and ytterbium/erbium (Yb/Er)-doped optical fibers. Their vulnerability to environment of outer space is evaluated through passive radiation-induced attenuation (RIA) measurements during after exposure 10 keV X-rays, 1 MeV <formula formulatype="inline"> <tex Notation="TeX">$\gamma$</tex></formula>-rays,...
Abstract Ensuring self-driven mode-locking and broadband wavelength tuneability in all-fibre-integrated femtosecond laser sources enables a new level of their versatility extends areas applications. Principle limitations for this are traditionally available ultrafast modulators techniques. Here, we exploit Thulium-doped fibre to perform three roles the cavity: gain, saturable absorber, element via controlling its excitation level. We confirmed that Tm-doped absorption is defined by...
We report on an extensive investigation of photodarkening in Ybdoped silica fibers.A set similar fibers, covering a large Yb concentration range, was made so as to compare the induced losses.Careful measurements were ensure equal and uniform inversion for all tested fibers.The results show that, with specific set-up, stretching parameter obtained through fitting has very limited variation.This gives more meaning parameters.Results tend indicate square law dependence excited ions final...
Controlling the growth of zinc oxide nanowires is necessary to optimize performance nanowire-based devices such as photovoltaic solar cells, nano-generators, or light-emitting diodes. With this in mind, we investigate nucleation and mechanisms ZnO grown by metalorganic vapor phase epitaxy either on O-polar sapphire substrates. Whatever substrate, are Zn-polar, demonstrated convergent beam electron diffraction. For found sit pyramids. As proceeds, inversion domain boundary moves up order...
An efficient actively Q-switched Tm3+-doped single-oscillator fiber laser based on a silica polarization-maintaining (PM) double-clad provided average powers of 23 W at pulse widths 65 ns 40 kHz repetition frequency. It was used to directly pump ZnGeP2 optical parametric oscillator (OPO). Up 6.5 were generated in mid-IR wavelength range.
We present a bi-directionally 793-nm diode-pumped Tm 3+ , Ho -codoped silica polarization maintaining double-clad all-fiber laser based on single-oscillator architecture emitting 195 W at 2.09 µm in continuous wave mode of operation, with beam quality near the diffraction limit (M 2 = 1.08). The power scaling is only pump-power-limited range total available pump (540 W).
We developed a new holmium-doped triple-clad fiber (Ho-3CF), reducing the clad diameter to improve overlap between pump and doped-core, holmium concentration reduce influence of ion clustering on laser efficiency. illustrate here performance this in oscillator configuration. The emission is centered at 2.12 $\mu$m by Bragg grating, active pumped 1.94 thulium-doped laser. slope efficiency reaches 73% with respect absorbed power (60% considering coupled power), for maximum signal 62 W...
LUMINA, a fiber-based dosimeter, exploiting the radiation induced attenuation phenomenon, is operational inside International Space Station since August 2021. We discuss in this article its capability to detect possible signatures of recent solar particle events through related increase dose rate level within (ISS). Our analysis over 699 days operation shows that two LUMINA channels, operating either visible or infrared domains, are able slight flares, particular Poles regions. The South...
We present a thulium-doped single-oscillator monolithic fiber laser emitting successively at three wavelengths, especially unusual long wavelengths as 2.09 µm and even 2.12 µm. The 793 nm core absorption of 8.42 dB/m allows for achieving slope efficiency higher than 43% both 1.94 operation the µm, is compared by using different Bragg gratings to push limit thulium ions emission above 2.05 This first demonstration exceeding 2.1 an only laser, best our knowledge.
In the present study, we examined photodarkening loss reduction in Yb3+ doped aluminosilicate fibers by utilizing 633 nm light irradiation. It is demonstrated that final photobleaching value intensity dependent, but percentage of does not depend on dopant concentrations for settled bleaching intensity. Further examination was committed to explore starting from different levels while keeping same concentration and subsequently other way around. This approach related with number induced color...
In this work, the influence of photodarkening (PD) and photobleaching (PB) on lasing features ytterbium-doped aluminosilicate fiber lasers is examined. Simultaneous PD PB with 633 nm irradiation was monitored at wavelength 1070 compared individually caused effects. The variation laser threshold slope efficiency reported. By analyzing performances it found that ratio excess loss expected to be less than 20. addition, considerable mitigation light demonstrated.
The radiation responses of different high-power erbium/ytterbium-codoped fiber amplifiers (HP-EYDFA) have been investigated up to 100 krad (SiO2) dose levels. These devices are able deliver 20 W signal output power at 1565 nm by pumping 915 (43 W) tolerant (Er/Yb) or hardened (ErYbCe) active few mode fibers; these performances needed for free-space communications between low-orbit satellites and ground transceivers. X-ray irradiation results show that, thanks a positive influence the photo-...
Fiber Bragg Grating (FBG) based sensors are nowadays used for several applications, but, even if they present advantages their incorporation into radiation environments, commercial-off-the-shelf devices cannot still be in harsh conditions. We recently reported a procedure fabricating FBGs resistant to severe constraints combining both high doses up MGy levels and operation temperatures exceeding 200°C (RadHard FBGs). Following these results, the European project HOBAN was granted by Kic...
Based on the experience acquired early from pioneering work at Stanford University and Thomson-CSF starting in mid 70s, fiber optic gyro (FOG) R&D began Photonetics late 80s to yield OCTANS, a FOG-based inertial strapdown system providing attitude compassing, end of 90s. This FOG activity was spun out October 2000 create iXsea with only 16 people. The product line rapidly expanded PHINS, an inertial-grade INS (Inertial Navigation System) later MARINS, strategic-grade INS, as well ASTRIX...
We report on our realization of a high-power holmium doped fiber laser, together with the validation numerical simulation laser. first present measurements physical parameters that are mandatory to model accurately laser-holmium interactions in silica fiber. then describe clad-pumped based triple-clad large mode area (Ho) The output signal power is 90 W at 2120 nm, an efficiency about 50% respect coupled pump power. This corresponds state art for Ho-doped lasers 100 class. By comparing...
Harsh environments can combine radiations and extreme temperature constraints, which both degrade the optical performances of silica-based fibers (OFs). Among different types OFs, ones having a core in pure-silica or doped with fluorine are known to present, generally, lowest steady-state radiation-induced attenuation (RIA) high cumulated doses ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$>$...
Nanowire-based light-emitting devices require multi-quantum well heterostructures with high room temperature optical efficiencies. We demonstrate that such efficiencies can be attained through the use of ZnO/Zn(1−x)MgxO core–shell quantum grown by metal organic vapor phase epitaxy. Varying barrier Mg concentration from x = 0.15 to 0.3 leads formation misfit induced dislocations in wells. Correlatively, dependent photoluminescence reveals radial luminescence intensity decreases much less...