Nonlinear polarization dynamics of Kerr beam self-cleaning in a GRIN multimode optical fiber

We experimentally study polarization dynamics of Kerr beam self-cleaning in a graded-index multimode optical fiber. We show that spatial beam cleaning is accompanied by nonlinear polarization rotation, and a substantial increase of the degree of linear polarization.Comment: 5 pages, 6 figure

Adaptive Kerr-assisted transverse mode selection in multimode fibers

Multimode optical fibers (MMFs) have recently regained interest because of the degrees of freedom associated with their different eigenmodes. In the nonlinear propagation regime in particular, new phenomena have been unveiled in graded-index (GRIN) MMFs such as geometric parametric instabilities and Kerr beam self-cleaning [1, 2]. The speckled pattern observed at the output of the MMF at low powers, is transformed at high powers into a bell-shaped beam close to the fundamental mode. Recent work has also demonstrated that Kerr beam self-cleaning can lead to a low-order spatial mode, different from a bell-shape, by adjusting the laser beam in-coupling conditions [3]. An attractive way to systematically control the spatial excitation conditions at the fiber input is provided by the use of a spatial light modulator (SLM) which permits to profile the beam wavefront entering the MMF. In most cases, experiments involving adaptive optics consider linear propagation through scattering plates or MMFs [4]. So far, few works have dealt with the nonlinear propagation regime[5, 6]

Spatio-temporal reshaping in multimode fibers

Multimode fibers received recently a renewed interest because of the ability to control the multimode propagation and to select, at the output, a quasi-single mode supporting the main part of the energy. In this paper we present results on spatial Kerr-beam self-cleaning in multimode optical fiber. We show how a speckled beam obtained because of multimode propagation can be transformed into a quasi-single-mode emission under the effect of the peak power increas

Systèmes lasers intégrant des micro-miroirs déformables a base de MEMS optiques

This work deals with the integration of MEMS (Micro- Electro- Mechanical- System) in fibre laser systems in order to generate short pulses. Q-switching short laser cavities associated with these components produces pulses in the nanosecond regime. These deformable micro-mirrors reached modulation frequencies upper than one megahertz, giving access to mode-locking in fibre laser sources. This new fibre laser system showed MOEMS capability to replace more famous modulators, as acousto-optic or electro-optic ones. They offer a good potential in miniaturization and cost reduction of pulsed fibre laser sources.LIMOGES-BU Sciences (870852109) / SudocSudocFranceF

On-line deformation measurements of nuclear fuel rod cladding using speckle interferometry

International audienc

Démarche d'optimisation d'un procédé de fabrication de comprimés via granulation humide

LYON1-BU Santé (693882101) / SudocSudocFranceF

On-line deformation measurements of nuclear fuel rod cladding using speckle interferometry

International audienc