Search results for "fiber"
showing 10 items of 2343 documents
Wave turbulence in integrable systems: nonlinear propagation of incoherent optical waves in single-mode fibers.
2011
International audience; We study theoretically, numerically and experimentally the nonlinear propagation of partially incoherent optical waves in single mode optical fibers. We revisit the traditional treatment of the wave turbulence theory to provide a statistical kinetic description of the integrable scalar NLS equation. In spite of the formal reversibility and of the integrability of the NLS equation, the weakly nonlinear dynamics reveals the existence of an irreversible evolution toward a statistically stationary state. The evolution of the power spectrum of the field is characterized by the rapid growth of spectral tails that exhibit damped oscillations, until the whole spectrum ultima…
Regions of Existence and Transformations of (3+1)-D Dissipative Optical Solitons
2006
We demonstrate the existence of stable optical light bullets in nonlinear dissipative media featuring both normal and anomalous chromatic dispersion. Beyond the domain where stable bullets are found, unstable bullets can be transformed into "rockets".
Peregrine soliton in optical fiber-based systems
2011
International audience; We report the first observation in optics of the Peregrine soliton, a novel class of nonlinear localized structure. Two experimental configurations are explored and the impact of non-ideal initial conditions is discussed.
Numerical Maps for Fiber Lasers Mode Locked with Nonlinear Polarization Evolution: Comparison with Semi-Analytical Models
2008
We have used a fully vectorial model based on two coupled nonlinear Schrodinger equations to study mode locking and pulse generation initiated and stabilized by nonlinear polarization evolution in a stretched pulse, double-clad, Yb-doped, fiber laser. The model takes explicitly into account gain saturation, finite amplification bandwidth, Kerr-induced self- and cross-phase modulations, group velocity dispersion, polarization control, and linear birefringence. Complete maps versus the orientation of intra-cavity wave-plates have been established. They comprise a large variety of pulse regimes that can be simply obtained by turning the intracavity wave-plate: stable single pulse per round tri…
Light-by-light polarization control and stabilization in optical fibers for telecommunication applications
2012
With the advent of future transparent ultra high-bit rate capacity transmission networks, encoding the data would necessary involve all the physical parameters of a light beam, including multi-level in intensity, phase, polarization and even propagation modes. These complex optical fields will then naturally suffer from strong impairments imposed by linear and nonlinear propagation effects. Hence, developing new all-optical tools able to control or regenerate any properties of light has become of a crucial interest. In this work, we experimentally report that it is possible, using a unique segment of optical fiber, to all-optically manipulate and regenerate both the state of polarization (S…
Statistical analysis of pulse propagation driven by polarization-mode dispersion
2002
International audience; The linear propagation of pulses driven by random polarization-mode dispersion is considered. Analytical expressions are derived for the probability-density functions of the pulse width, timing displacement, and degree of polarization. The study is performed in Stokes space, and frequency correlation between modes is shown to play an important role in it.
Nonlinear spectral compression in optical fiber: A new tool for processing degraded signals
2017
International audience; We propose two new applications of the spectral focusing by self-phase modulation that occurs in a nonlinear optical fiber. We numerically show the possibility of using nonlinear spectral compression to improve the optical signal to noise ratio and mitigate the amplitude jitter of the signal pulses. We also demonstrate experimentally that use of spectral focusing in a combination with an external sinusoidal phase modulation achieves efficient suppression of coherent spectral background.
Performance optimisation of dual-pump NALM fibre laser using machine learning inference
2018
We apply predictive regression to find optimum operating regimes in a recently proposed layout of a flexible Figure-8 laser having two independently pumped segments of active fibre in its bidirectional ring.
Coupled experiment/simulation approach for the design of radiation-hardened rare-earth doped optical fibers and amplifiers
2011
We developed an approach to design radiation-hardened rare earth -doped fibers and amplifiers. This methodology combines testing experiments on these devices with particle swarm optimization (PSO) calculations. The composition of Er/Yb-doped phosphosilicate fibers was improved by introducing Cerium inside their cores. Such composition strongly reduces the amplifier radiation sensitivity, limiting its degradation: we observed a gain decreasing from 19 dB to 18 dB after 50 krad whereas previous studies reported higher degradations up to 0°dB at such doses. PSO calculations, taking only into account the radiation effects on the absorption efficiency around the pump and emission wavelengths, co…
On the possibility of observing bound soliton pairs in a wave-breaking-free mode-locked fiber laser
2007
On the basis of numerical simulations, we explain the formation of the stable bound soliton pairs that were experimentally reported in a high-power mode-locked ytterbium fiber laser [Opt. Express 14, 6075 (2006)], in a regime where wave-breaking-free operation is expected. A fully vectorial model allows one to rigorously reproduce the nonmonotonic nature for the nonlinear polarization effect that generally limits the power scalability of a single-pulse self-similar regime. Simulations show that a self-similar regime is not fully obtained, although positive linear chirps and parabolic spectra are always reported. As a consequence, nonvanishing pulse tails allow distant stable binding of high…