Search results for " Optics"
showing 10 items of 5880 documents
Nonlinear Sculpturing of Optical Pulses in Fibre Systems
2019
The interplay among the effects of dispersion, nonlinearity and gain/loss in optical fibre systems can be efficiently used to shape the pulses and manipulate and control the light dynamics and, hence, lead to different pulse-shaping regimes [1,2]. However, achieving a precise waveform with various prescribed characteristics is a complex issue that requires careful choice of the initial pulse conditions and system parameters. The general problem of optimisation towards a target operational regime in a complex multi-parameter space can be intelligently addressed by implementing machine-learning strategies. In this paper, we discuss a novel approach to the characterisation and optimisation of …
Quasi-soliton spatial autoguidé en milieu non lineaire quadratique
2021
International audience; Nous démontrons ici des phénomènes d'autoguidage optique existant dans les milieux à non-linéarités quadratiques. En plus de la formation puis disparition d'un phénomène auto confiné, nous observons des effets de commutation ultrarapide et de démultiplication spatiale, ainsi qu'une restructuration temporelle suivie d'élargissements spectraux.
New fiber laser architecture with transform-limited nonlinear spectral compression
2012
International audience; We numerically demonstrate a new fiber laser architecture supporting spectral compression of negatively chirped pulses in passive normally dispersive fiber. Such a process is beneficial for improving the energy efficiency of the cavity as it prevents narrow spectral filtering from being highly dissipative. The proposed laser design provides an elegant way of generating transform-limited picosecond pulses.
Weak Langmuir turbulence in disordered multimode optical fibers
2021
We consider the propagation of temporally incoherent waves in multimode optical fibers (MMFs) in the framework of the multimode nonlinear Schr\"odinger (NLS) equation accounting for the impact of the natural structural disorder that affects light propagation in standard MMFs (random mode coupling and polarization fluctuations). By averaging the dynamics over the fast disordered fluctuations, we derive a Manakov equation from the multimode NLS equation, which reveals that the Raman effect introduces a previously unrecognized nonlinear coupling among the modes. Applying the wave turbulence theory on the Manakov equation, we derive a very simple scalar kinetic equation describing the evolution…
All-optical nonlinear simultaneous polarization and intensity regeneration of a 40-Gb/s telecommunication signal
2012
We experimentally report the simultaneous all-optical regeneration of the polarization state and the intensity profile of a 40 Gb/s Return-to-Zero telecommunication signal by means of Kerr effect occurring in a single segment of fiber.
Four-wave mixing process induced by a self-phase modulated pulse in a hollow core capillary
2021
International audience; <span class="markedContent" id="page11R_mcid8"><span style="left: 247.583px; top: 366.24px; font-size: 16.6667px; font-family: sans-serif;" role="presentation" dir="ltr"></span><span style="left: 253px; top: 366.24px; font-size: 16.6667px; font-family: sans-serif; transform: scaleX(0.941702);" role="presentation" dir="ltr">In this work, we investigate the modal </span><span style="left: 518.183px; top: 366.24px; font-size: 16.6667px; font-family: sans-serif;" role="presentation" dir="ltr"> </span><span style="left: 519.8px; top: 366.24px; font-size: 16.6667px; font-family: sans-serif; transform: scaleX(0.958087);" role="presentation" dir="ltr">four wa…
Self-Optimising Breather Ultrafast Fibre Laser
2021
We demonstrate the self-optimisation of the breather regime in an ultrafast fibre laser through an evolutionary algorithm. Depending on the specified merit function, single breathers with controllable breathing ratio and period, and breather molecular complexes with a controllable number of constituents can be obtained.
All-fibered high-quality 28-GHz to 112 GHz pulse sources based on nonlinear compression of optical temporal besselons
2021
The generation of high quality pulse trains at repetition rates of several tens of GHz remains a crucial step for optical telecommunications, optical sampling or component testing applications. Unfortunately, the current bandwidth limitations of optoelectronic devices do not allow the direct generation of well-defined optical pulse trains with low duty cycles. An attractive solution is based on a direct temporal phase modulation that is then converted into an intensity modulation thanks to a dispersive element that imprints a spectral quadratic phase. Picosecond pulses at repetition rates of several tens of GHz have been successfully demonstrated [1] . However, this approach suffers from a …
Data Transmissions at 1.98 µm in cm-long SiGe Waveguides
2017
International audience; We demonstrate an error-free transmission of 10-Gbit/s optical signals along a SiGe waveguide at a wavelength of 1.98 μm. Bit error rate measurements confirm the absence of penalty during the transmission through a 2.5-cm long waveguide having a width of 2.2 μm.
Optical waveform tailoring in passive and laser cavity fibre systems
2019
International audience; The interplay among the effects of dispersion, nonlinearity and gain/loss in optical fibres is a powerful tool to generate a broad range of pulse shapes with tuneable properties. Here we propose a method to optimise the systems parameters for a given pulse target. By reducing the system complexity and applying machine-learning strategies, we show that it is possible to efficiently identify the sets of parameters of interest. Two configurations are numerically investigated: pulse shaping in a passive normally dispersive fibre and pulse generation in a dual-pump nonlinear-amplifying-loop-mirror mode-locked fibre laser.