Academic literature on the topic 'Laser fibré de haute puissance'
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Journal articles on the topic "Laser fibré de haute puissance":
Gallais, Laurent, and Laurent Lamaignère. "L’endommagement laser sur les lasers de puissance." Photoniques, no. 118 (2023): 46–52. http://dx.doi.org/10.1051/photon/202311846.
Biernat, A., and G. Kompa. "Powerful picosecond laser pulses enabling high-resolution pulsed laser radar." Journal of Optics 29, no. 3 (June 1998): 225–28. http://dx.doi.org/10.1088/0150-536x/29/3/023.
Kutchukian, S., L. Candela, D. Castellani, E. Ventimiglia, M. Chicaud, M. Corrales, F. Panthier, et al. "Comparaison des résultats de lithotripsie au laser thulium fibré et au laser Holmium:Yag de forte puissance chez des patients pédiatriques traités par urétéroscopie souple pour des calculs rénaux : étude rétrospective multicentrique." Progrès en Urologie - FMC 33, no. 3 (November 2023): S102—S103. http://dx.doi.org/10.1016/j.fpurol.2023.07.224.
Dissertations / Theses on the topic "Laser fibré de haute puissance":
Gouin, Samuel. "Cavités laser de haute puissance sans épissure." Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/31752.
In a rapidly growing market, high power fiber laser development is key in making this technology available to a large number of industries. Laser manufacturers must constantly develop new methods to upgrade lasers performances and reliability if they want to keep a significant market share. Fiber Bragg gratings (FBG) inscription in a continuous doped fiber segment allows the possibility for a splice less laser cavity, such a laser cavity being more reliable, fasterto build and granting higher laser efficiencies.The experiments demonstrated the feasibility of FBG inscription in an ytterbium doped fiber with a sufficient reflectivity and low enough heating losses to withstand an emission power of 538 W with 77% laser efficiency, the maximum power being currently limited by the available pump power. By extrapolating the data, it is found that the gratings have a low enough heating slope to support a laser emission of 1030 W. The different laser cavities assembled showed that it is very difficult to make a splice less single mode laser cavity in a high brightness fiber, because the injection mode filtering technique cannot be used. However, it has been shown that by using a large mode area fiber (LMA), a splice less single mode laser cavity can be made and that counter-pumping yields the best efficiency. Numerical simulations allowed us to understand that the power distribution inside of the laser creates an uneven heating between the FBG, making extra considerations mandatory to avoid spectral shift between the gratings. The project has shown that it is conceivable to commercialise a splice less laser emitting 1 kW in a near future and that the current available technology would allow such a realisation.
De, Mollerat Du Jeu Rémi. "Développement d'architectures de fibres structurées pour l'amplification d'impulsions haute puissance crête." Thesis, Limoges, 2018. http://www.theses.fr/2018LIMO0033/document.
As part of a CIFRE contract between Thales L.A.S. France and the XLIM laboratory (UMR 7252 of the CNRS and the University of Limoges), my thesis project consists in the development of ytterbium-doped optical fiber architectures for pulses amplification with high peak power at a wavelength of 1 µm in order to achieve a coherent beam combination to obtain a laser source with both a very high peak power and a high repetition rate. Based on a large-core fibre design called FA-LPF, two development axes are addressed. The first one concerns the tolerances improvement to an external bending applied on the FA-LPF. With the help of a numerical study, an innovative strategy is implemented to mitigate the effects of bending. The architecture is then called step-index assisted FA-LPF. A single a singlemode laser emission in continuous regime with an optical power of 65 W is demonstrated with a 60 cm bending radius for a 47 µm mode field diameter. The second axis is the implementation of the polarisation control in FA-LPFs. The goal is to obtain a linearly polarised signal. Several numerically tested architectures allow single linear polarisation propagation in passive structures over a broadband optical spectrum, including a singlemode single-polarisation propagation at 1400nm for a core diameter of 140 µm. The best architecture, called FA-LPF 4+2 SAP, is fabricated with active ytterbium dopants. Due to manufacturing defects, the obtained fibres act as polarisation maintaining fibres. A polarisation extinction ratio of 17 dB is obtained in an amplification configuration in continuous regime with 24 dB of gain (an emitted power of 50 W)
Mollerat, du Jeu Rémi de. "Développement d'architectures de fibres structurées pour l'amplification d'impulsions haute puissance crête." Electronic Thesis or Diss., Limoges, 2018. http://www.theses.fr/2018LIMO0033.
As part of a CIFRE contract between Thales L.A.S. France and the XLIM laboratory (UMR 7252 of the CNRS and the University of Limoges), my thesis project consists in the development of ytterbium-doped optical fiber architectures for pulses amplification with high peak power at a wavelength of 1 µm in order to achieve a coherent beam combination to obtain a laser source with both a very high peak power and a high repetition rate. Based on a large-core fibre design called FA-LPF, two development axes are addressed. The first one concerns the tolerances improvement to an external bending applied on the FA-LPF. With the help of a numerical study, an innovative strategy is implemented to mitigate the effects of bending. The architecture is then called step-index assisted FA-LPF. A single a singlemode laser emission in continuous regime with an optical power of 65 W is demonstrated with a 60 cm bending radius for a 47 µm mode field diameter. The second axis is the implementation of the polarisation control in FA-LPFs. The goal is to obtain a linearly polarised signal. Several numerically tested architectures allow single linear polarisation propagation in passive structures over a broadband optical spectrum, including a singlemode single-polarisation propagation at 1400nm for a core diameter of 140 µm. The best architecture, called FA-LPF 4+2 SAP, is fabricated with active ytterbium dopants. Due to manufacturing defects, the obtained fibres act as polarisation maintaining fibres. A polarisation extinction ratio of 17 dB is obtained in an amplification configuration in continuous regime with 24 dB of gain (an emitted power of 50 W)
Grande, Adrian. "Laser à fibres Tm : Ho de haute puissance à femtoseconde à 2050 nm." Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0021.
The chirped pulse amplification (CPA) technique was developed to power scale the pulsesfrom mode-locked oscillators as the pulse energy was not sufficient to target applicationssuch as strong field physics and particle acceleration. Since its development in 1985 ithas been applied in a wide variety of commercially available laser systems and ultra-highpower laser facilities. The technique allows to circumvent the accumulation of non-linearphase which hampers pulse compression and allows to maintain the fluence of the pulsesbelow the laser induced damage thresholds (LIDT) of components. In this thesis wedevelop CPA laser systems operating at 2.05μm wavelengths with high average powerand high energy starting from the development of the seed laser up to the design andimplementation of the pulse stretcher, amplifiers and pulse compressor.In the first section of the thesis we introduce the physics background and phenomenarequired for understanding the chirped pulse amplification technique and the developmentof the seed laser. This includes dispersion, self-phase modulation and Raman scattering.In the second section of the thesis we present the development of an all-fiber polarizationmaintaining laser tunable over 170nm, from 1880nm up to 2050nm via Ramansoliton self-frequency shift (SSFS). The system is based on exclusively commercially availablestandard fibers. We have characterised the laser in terms of power, spectrum andpulse duration and we have included a post-compression stage that relies on non-lineareffects to reach the sub-100 fs duration across the whole tunability range. Simulations ofthe soliton post-compression shows the versatility of the laser which allows to customisethe pulse duration over a spectral range or for a particular wavelength. We believe thatthe laser is a versatile and robust alternative to Tm and Tm:Ho oscillators.In the third section we have tested the tunable laser in a wide variety of stretchingand compression architectures suitable for CPA. We have investigated fibers and chirpedvolume Bragg gratings (CVBG) as pulse stretching devices and grating pairs and CVBGsas pulse compressors. We discuss how to dimension a stretching-compressor pair takinginto account the non-linear phase and gain narrowing effect that takes place during pulseamplification and how to evaluate the stretching-compressor performance. Two differentchirped pulse amplification laser systems have been designed and presented, the first onetargets broadband fs pulses with high average power and the second system targets highenergetic ps pulses. The non-mature technology in the 2μm spectral region and the weakavailability of suitable stretching devices hinders pulse compression at this wavelength.In the last section of the thesis we investigated the performance of Tm:Ho co-dopedfibers in amplification configuration. We discuss the main challenges of these fibers includingthe cross-relaxation effects, the availability of pump sources which gives rise totwo main pumping schemes: diode pumping and in-band pumping and the limitations interms of fiber size. We tested Tm:Ho doped fibers, including LMA for narrowband andbroadband pulse amplification
Brown, Dussault Evelyne. "Atténuation d'effets non linéaires dans les lasers fibrés de haute puissance opérés en régime continu." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27006.
High power fiber lasers are now the preferred solution when it comes to industrial cutting applications. Development and power scaling of industrial grade high power fiber lasers is however limited by industrial reliability specifications. Power scaling of fiber lasers is limited by non-linear effects, which arise from fiber designs with a small mode area therefore requiring the development of new methods to suppress non-linear effects. In this memoir, experiments and simulations show that the models used to describe nonlinear effects in the case of passive fibers are no longer valid in the case of high power fiber lasers. New metrics must thus be defined. We also show that the laser configuration influences the non-linear effects. Using the general non linear Schrödinger equation we also show that in the case of a high power end-pumped laser configuration, Raman scattering affects spectral broadening. Experimental and theoretical work also show that changing the grating mirror properties such as increasing the reflectivity or the bandwidth of the low reflectivity grating reduces Raman scattering.
Guiraud, Germain. "Développement de sources laser à fibres dopées ytterbium haute puissance, monofréquence et à bas bruit d'intensité." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0648.
High power, narrow linewidth fiber lasers are useful for both industrial and scientific applications. Nevertheless, nonlinear effects like Stimulated Brillouin Scattering (SBS) are main limitations of these laser sources due to high power in fiber core. A first amplifier in single-frequency operation with 50W of output power from a laser diode seeder of 50 mW was developed. Study of intensity noise on this amplifier developed with standard fiber (core diameter less than 20 μm) showed that SBS leads to a degradation of noise properties of the laser. The use of large mode area (LMA) fibers is a solution for suppressing nonlinear effects with core diameters bigger than several tens of microns. LMA fibers show an overlap between doped core and pump wave optimized leading to a reduction of gain medium length. This strategy permits to increase nonlinear effect threshold. Second step of high power amplifiers with LMA fibers allows to obtain 100W in single-frequency regime without DBS. LMA fiber used have a core diameter equals to 40μm. Power scaling from 100W to 200W highlights a new limiting non-linear effect: Fiber Modal Degradation (FMD). Indeed, multimodal cores of these fibers, coupled to high thermal load lead to non-linear effects like Modal Instabilities (IM) and FMD. FMD effect, first described by Ward et al in 2016, is a thermo-optic effect characterized by a beam quality degradation with power transfer from fundamental mode to high order modes. Furthermore, a decrease of output power, synonym of guidance loss of fundamental mode in gain medium is observed. Unlike well-known effect IM, this phenomenon doesn’t act like a threshold phenomenon. In fact, transitory regime in association with FMD is longer than IM caused by photodarkening dynamic. In our study, beam quality at the output of the fiber was degraded after several tens of hours at 200W. For understanding this effect, a photodarkening effect study both in continuous wave (CW) and pulsed regime was carried out. This study shows that for the first time a photodarkening and photobleaching equilibrium on high power amplifiers in pulsed regime. These thermo-induced effects threshold depends on thermal load and are different for both regimes: 120W for CW and 150W for pulsed regime. Finally, a study and a reduction of intensity noise based from a servo-loop were carried out on 100W amplifier. A 1MHz bandwidth with a 30 dB decrease of noise were demonstrated. These results allow to develop high power and low intensity noise lasers at industrial level”
Benoit, Aurélien. "Sources laser fibrées hybrides de haute puissance : Amplification et conversion de fréquences." Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0024/document.
High-power fiber lasers adress an increasing number of applications since ten years. In the frame of a CIFRE contract between the company Eolite Systems and Xlim (joint laboratory between CNRS and the University of Limoges), the goal of this PhD project was to develop the technological blocs to achieve all-fibre high-power lasers emiting out of the conventional spectral band covered by existing lasers.Modal instabilities in large mode area (LMA) fibers are currently the main limitation of the fiber lasers power scaling. We have experimentally demonstrated the relevance of inner cladding aperiodic structures to efficiently delocalize higher order modes outside the gain region. A systematic study of passive fibers based on such structures has shown the single propagation of the fundamental mode over a wide wavelength range from 1 to 2 µm for dimension of core up to 85 µm. This effective mode delocalization even extends up to a core dimension of 140 µm at a 2 µm wavelength.The combination of high power picosecond fiber laser with an average power of 22.7 W and a hydrogen-filled inhibited coupling Kagome fiber allowed us to generate two Raman combs over five frequency octaves from 321 nm to 12.5 µm. These two combs are controlled by the laser pump polarization and generated an average power of 10.1 W displayed over 70 laser lines for circular pump polarization and 8.6 W over 30 lines for linear polarization. Some laser lines within these combs have been generated for the first time from high-power fiber source in the mid-infrared range. We have also demonstrated the generation of high-power line by optimizing the first vibrational Stokes at 1.8 µm with an average power of 9.3 W and a quantum efficiency of the frequency conversion stage close to 80%
Wei, Li-Wei. "Système laser de haute-puissance pour le projet Advanced Virgo : les amplificateurs à fibre combinés de façon cohérente." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4091/document.
Virgo is a cavity-enhanced Michelson interferometer built for the direct detection of gravitational waves. The Advanced Virgo project consists of major upgrades to the Virgo gravitational wave detector for an order of magnitude improvement in differential strain sensitivity, one of which is the tenfold increase in injected laser power to 175 Watts. The use of fiber laser amplifiers and their coherent combination are foreseen to deliver the required high-power low-noise beam. In this thesis work, we review the laser requirements for gravitational wave detectors, introduce the design of the laser system for Advanced Virgo, and develop the means for laser characterization in accordance with the stringent noise specifications. We then present the results to date, notably the quasi-continuous long-term operation of two 40-Watt fiber laser amplifiers over thousands of hours and their coherent combination with Mach-Zehnder interferometry. Although the targeted power for Advanced Virgo is not yet attained, the developed system shows decent noise performance and is promising for further power-scaling efforts
Abbouab, Clara. "Étude et conception de sources laser fibrées monomodes en régime continu multi-kW." Electronic Thesis or Diss., Limoges, 2023. http://www.theses.fr/2023LIMO0088.
This CIFRE thesis is a collaboration between the XLIM research laboratory and the industrial laser company "CILAS". The main objective of this work is to study and design high power fiber laser sources delivering a continuous wave single mode laser beam with an output power of several kW. To this end, the “MOPA” design (consisting a master oscillator stage and a power amplifier stage) was chosen from the literature and then has been built at XLIM. To the best of our knowledge, it is the first time in France that 2 kW of continuous wave output power has been achieved at the signal wavelength of 1080 nm. Thanks to the experimental results, a simulation tool was calibrated and used to carry out a theoretical study of the limits of this laser source. This tool has also been used to propose some improvements of this architecture by changing the pump wavelength, the signal wavelength, the doped fiber and the combination of the pump power between the two directions of propagation. The results of the simulations were compared with the experimental results obtained from a new source reaching more than 3 kW of continuous wave power. Finally, another less complex design, called OAIFL, was calibrated using the simulation and then built. A supercontinuum was generated by exploiting the temporally unstable laser cavity, delivering a power of 40.7 W over a spectrum going from 750 nm to 2200 nm at - 30 dB. As a perspective, the simulation showed that the OAIFL source could be further amplified to reach up to 3 kW. Therefore, this laser source could be further developed in the future
Ghawas, Muhammad. "Sources picosecondes et femtosecondes à base de fibre dopées Ytterbium et applications." Electronic Thesis or Diss., Bordeaux, 2023. http://www.theses.fr/2023BORD0463.
Ultrashort laser pulses in both industrial and research applications progressively rely on fiber laser technology, guided by its intrinsic benefits, for instance, stability, compact nature, excellent beam quality, robustness, and easy operation. In this work, a detailed study has been done to investigate picosecond fiber laser working in an all-normal-dispersion (ANDi) regime for the application of parametric generation in photonic crystal fiber. In summary, we have developed a high-power fiber laser source delivering picosecond pulses with tunability both in central wavelength and spectral width. It incorporates a combination of a large-mode-area rod-type ytterbium fiber, a slit, and a transmission grating inside the ring laser cavity configuration. At the central wavelength of ∼ 1030 nm and with a repetition of 78 MHz, this laser delivers picosecond pulses with an average power of up to 25 W. The pulse duration can be continuously adjusted from ∼ 1.8 ps to ∼ 4.5 ps and pulse energy from ∼ 320 nJ and ∼ 225 nJ, respectively. Additionally, we have also demonstrated that the central wavelength of the laser pulse can be finely tuned from ∼ 1010 nm to ∼ 1060 nm while keeping the pulse energy above ∼ 150 nJ. We have also proposed a numerical model to account for the ensemble of our experimental data and the simulations are in good agreement with the experimental data. The output of this fiber oscillator is propagated through the photonic crystal fiber for the parametric generation of the signal (higher frequencies than the pump) and idler (lower frequencies than the pump). The fiber OPO singly-resonant cavity was built in such a way that only signal wavelengths are allowed to propagate through it. The conversion efficiency for the signal was close to 20 % in the fiber OPO. Based on the dispersion profile of the photonic crystal fiber and our homebuilt tunable pump laser, the signal wavelength (resp. idler) was tuned from ∼ 770 nm to ∼ 1000 nm (∼ 1130 nm to ∼ 1590nm) for the corresponding pump wavelengths of ∼ 1024 nm to ∼ 1059 nm