Microstructured air-silica fibres: Recent developments in modelling, manufacturing and experiment

37 pagesInternational audienceThe main modelling methods devoted to microstrutured air-silica optical fibres (MOFs) are presented and discussed. Then, the specific propagation properties of MOFs are studied in detail. Characteristics measured on fibres manufactured in our laboratory or reported in the literature are analysed. A large number of potential and demonstrated applications are presented and the obtained performances are discussed. A particular attention is given to hollow- core photonic bandgap fibres and their applications

High power femtosecond chirped pulse amplification in large mode area photonic bandgap Bragg fibers

International audienceWe report on high power amplification of femtosecond pulses in 40-μm core diameter Yb-doped photonic bandgap Bragg fibers. The robustness to bending and transverse spatial behavior of these fibers is analyzed through simulations. The fibers are used in both stages of a moderately stretched (150 ps) femtosecond chirped pulsed amplification (CPA) system. A compressed average power of 6.3W is obtained using a low-index polymer-coated Bragg fiber with excellent beam quality and high efficiency, in agreement with numerical simulations. The use of an air-clad Bragg fiber allows us to scale the output power to 47 W at a repetition rate of 35MHz. This experiment demonstrates the great potential of Bragg fibers to increase the mode area and the power of practical bending-tolerant femtosecond fiber systems

Chalcogenide As2S3 suspended core fiber for mid-IR wavelength conversion based on degenerate four-wave mixing

International audienceA chalcogenide optical fiber of special design is proposed to convert a short-wavelength IR radiation (around 2 μm) up to second transparency window of atmospheric air (around 4.5 μm) by degenerate four-wave mixing. The fiber supports a small core surrounded by three large air holes. The zero-dispersion wavelength is shifted down to 2 μm in this fiber by properly tailoring geometry of the fiber core. We demonstrate by solving the nonlinear Schrödinger equation that efficient wavelength-conversion can be obtained by pumping the fiber with a Tm:SiO2 pulsed fiber laser

Short wavelength (UV + VIS) guidance in kagomé lattice hollow core photonic crystal fibre

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Solid-core photonic bandgap fibers for high-power fiber lasers

International audienceAn overview of various designs of large-mode-area photonic bandgap fibers (PBGFs) is presented in this paper. Bending properties of these structures are discussed and compared with those of step-index and air-silica microstructured fibers. Peculiarities of active PBGF fabrication are considered, and novel high-power laser architecture based on such fibers is described

Emission multi longueurs d'onde par cascade Raman dans une fibre optique de chalcogénure

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Understanding origin of loss in large pitch hollow-core photonic crystal fibers and their design simplification

International audienceIt is now commonly accepted that, in large pitch hollow-core 'kagomé' lattice fibers, the loss spectrum is related to resonances of the thin silica webs in the photonic crystal cladding. Moreover, coherent scattering from successive holes' layers cannot be obtained and adding holes' layers does not decrease the loss level. In this communication, cross-comparison of experimental data and accurate numerical modeling is presented that helps demonstrate that waveguiding in large pitch hollow-core fibers arises from the antiresonance of the core surround only and does not originate from the photonic crystal cladding. The glass webs only mechanically support the core surround and are sources of extra leakage. Large pitch hollow-core fibers exhibit features of thin walled and thick walled tubular waveguides, the first one tailoring the transmission spectrum while the second one is responsible for the increased loss figure. As a consequence, an approximate calculus, based on specific features of both types of waveguides, gives the loss spectrum, in very good agreement with experimental data. Finally, a minimalist hollow-core microstructured fiber, the cladding of which consists of six thin bridges suspending the core surround, is proposed for the first time

100 W from a photonic bandgap Bragg fiber laser

International audience100 W output power from Yb-doped LMA photonic bandgap Bragg fiber laser is reported. 81% slope efficiency was obtained. To our knowledge, this is the highest output power generated from an active photonic bandgap fiber

3D Modeling of Modal Competition in Fiber Laser: Application to HOM Suppression in Multi-Layered Fiber

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