1,721,585 research outputs found
Exploitation de l'autoglissement frequentiel soliton limite par des radiations de cherenkov pour generer deux impulsions au decalage frequentiel ou temporel continument ajustable
No full textNous exploitons l’apparition de radiations de Cherenkov qui limitent l’autoglissement fréquentiel d’une impulsion soliton pour proposer une source de deux impulsions ultrabrèves dont, suivant l’énergie initiale, il est possible de contrôler de manière continue soit l’écart fréquentiel, soit l’écart temporel
Evolution d'impulsions paraboliques dans un amplificateur a fibre optique hors regime asymptotique
No full textWe show analytically and numerically that parabolic pulses and similaritons are not always synonyms and that a self-phase modulation amplification regime can precede the self-similar evolution. Properties of the recompressed pulses after SPM amplification are investigated. We also demonstrate that negatively chirped parabolic pulses can exhibit a spectral recompression leading to high-power chirp-free parabolic pulses
Design scaling laws for self-phase modulation-based 2R-Regenerators
No full textWe report global scaling laws linking the design of SPM-based 2R-regenerators to their ability to reduce amplitude noise and improve the signal extinction ratio
Regles de conception pour les regenerateurs optiques 2-R exploitant l'auto-modulation de phase
No full textNous présentons des règles de conception générales concernant l’optimisation de régénérateurs 2R exploitant l’auto-modulation de phase. Nous étudions les performances des dispositifs optimisés en termes d’amélioration du taux d’extinction et de réduction de la gigue d’amplitude
Asymptotic properties of incoherent waves propagating in an all-optical regenerators line
No full textWe present an original method to generate optical pulse trains with random time-interval values from incoherent broadband sources. More precisely, our technique relies on the remarkable properties of a line made of cascaded self-phase modulation-based optical regenerators. Depending on the regenerator parameters, various regimes with noticeably different physical behaviors can be reported
Influence of the pump shape on the modulation instability process induced in a dispersion oscillating fiber
No full textInternational 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
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Pulse shaping in mode-locked fiber lasers by in-cavity spectral filter
Get PDFWe numerically show the possibility of pulse shaping in a passively mode-locked fiber laser by inclusion of a spectral filter into the laser cavity. Depending on the amplitude transfer function of the filter, we are able to achieve various regimes of advanced temporal waveform generation, including ones featuring bright and dark parabolic-, flat-top-, triangular- and saw-tooth-profiled pulses. The results demonstrate the strong potential of an in-cavity spectral pulse shaper for controlling the dynamics of mode-locked fiber lasers
Parabolic pulse generation through passive nonlinear pulse reshaping in a normally dispersive two segment fiber device
No full textWe numerically and experimentally demonstrate that pulses with a parabolic intensity profile can be formed by passive reshaping of more conventional laser pulses using nonlinear propagation in a length of normally dispersive nonlinear fibre. Moreover, we show that the parabolic shape can be stabilised by launching these pulses into a second length of fiber with suitably different nonlinear and dispersive characteristics relative to the initial reshaping fiber
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