Multiwavelength high-repetition rate source

International audienceWe propose and experimentally validate an all-optical approach to generate simultaneously several pulse trains with identical temporal and spectral properties. Applying a temporal sinusoidal phase modulation followed by a shaping of the spectral phase enables us to handle several channels. The principle of operation is experimentally demonstrated at repetition rates of 14 and 40 GHz with up to four channels

Compression spectrale dans les fibres optiques en présence de dispersion normale

National audienceNous étudions numériquement le phénomène de compression spectrale se déroulant dans une fibre optique à dispersion normale. Les conditions conduisant à une impulsion en quasi-limite de Fourier sont déterminées et nous montrons que loin de dégrader les performances, la présence de dispersion normale permet une amélioration significative des résultats

Machine learning approach for nonlinear pulse shaping in optical fibres

We use a supervised machine-learning approach to solve both the direct and inverse problems relating to the nonlinear shaping of optical pulses in optical fibres

Doublement d'impulsion dans une fibre à dispersion oscillante

National audienceEn exploitant une fibre à dispersion oscillante fonctionnant au point d’éclatement spectral des bandes de gain, nous montrons numériquement qu’il est possible de créer à partir d’une impulsion pompe un doublet de deux impulsions picosecondes avec un délai les séparant pouvant être ajusté sur une large plage

Enhanced spectral compression in nonlinear optical fibres

We propose two new approaches to enhance the spectral compression process arising from nonlinear pulse propagation in an optical fibre. We numerically show that an additional sinusoidal temporal phase modulation of the pulse enables efficient reduction of the intensity level of side lobes in the spectrum. Another strategy is to select a regime of propagation in which normal group-velocity dispersion reshapes the initial stretched pulse to a near-Fourier-transform-limited rectangular waveform

Design rules for nonlinear spectral compression in optical fibers

International audienceWe present comprehensive design rules to optimize the process of spectral compression arising from nonlinear pulse propagation in an optical fiber. Extensive numerical simulations are used to predict the performance characteristics of the process as well as to identify the optimal operational conditions within the space of system parameters. It is shown that the group-velocity dispersion of the fiber is not detrimental and, in fact, helps achieve optimum compression. We also demonstrate that near-transform-limited rectangular and parabolic pulses can be generated in the region of optimum compression

Nonlinear pulse shaping in fibres for pulse generation and optical processing

The development of new all-optical technologies for data processing and signal manipulation is a field of growing importance with a strong potential for numerous applications in diverse areas of modern science. Nonlinear phenomena occurring in optical fibres have many attractive features and great, but not yet fully explored, potential in signal processing. Here, we review recent progress on the use of fibre nonlinearities for the generation and shaping of optical pulses and on the applications of advanced pulse shapes in all-optical signal processing. Amongst other topics, we will discuss ultrahigh repetition rate pulse sources, the generation of parabolic shaped pulses in active and passive fibres, the generation of pulses with triangular temporal profiles, and coherent supercontinuum sources. The signal processing applications will span optical regeneration, linear distortion compensation, optical decision at the receiver in optical communication systems, spectral and temporal signal doubling, and frequency conversion

Compression spectrale améliorée par une modulation de phase corrective sinusoïdale

National audienceEn exploitant une modulation de phase sinusoïdale temporelle additionnelle, nous montrons qu’il est possible d’améliorer significativement les performances d’une compression spectrale réalisée en régime de propagation hautement non-linéaire. Les simulations numériques indiquent ainsi une amélioration des facteurs de compression ainsi que du rapport de Strehl

Influence of the pump shape on the modulation instability process induced in a dispersion-oscillating fiber

International audienceWe show that taking into account the temporal intensity profile of a pulsed pump beam may lead to significant deviations from the predictions based on continuous wave analysis of the modulation instability process occurring in a dispersion-oscillating fiber operating under the conditions that lead to gain sideband splitting. Potential application to a pulse doubling scheme with tunable delay is discussed

Nonlinear pulse sculpturing in passive and laser cavity fibre systems

The interplay among the effects of dispersion, nonlinearity and gain/loss in optical fibers is a powerful tool to generate a broad range of pulse shapes with tunable properties. Here we propose a method to optimize 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 fiber and pulse generation in a dual-pump nonlinear-amplifying-loop-mirror mode-locked fiber laser