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Author: Javaloyes, Julien × Publisher: Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik ×

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Now showing 1 - 5 of 5
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    Light bullets in a time-delay model of a wide-aperture mode-locked semiconductor laser
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2018) Pimenov, Alexander; Javaloyes, Julien; Gurevich, Svetlana V.; Vladimirov, Andrei G.
    Recently, a mechanism of formation of light bullets (LBs) in wide-aperture passively modelocked lasers was proposed. The conditions for existence and stability of these bullets, found in the long cavity limit, were studied theoretically under the mean field (MF) approximation using a Haus-type model equation. In this paper we relax the MF approximation and study LB formation in a model of a wide-aperture three section laser with a long diffractive section and short absorber and gain sections. To this end we derive a nonlocal delay-differential equation (NDDE) model and demonstrate by means of numerical simulations that this model supports stable LBs. We observe that the predictions about the regions of existence and stability of the LBs made previously using MF laser models agree well with the results obtained using the NDDE model. Moreover, we demonstrate that the general conclusions based upon the Haus model that regard the robustness of the LBs remain true in the NDDE model valid beyond the MF approximation, when the gain, losses and diffraction per cavity round-trip are not small perturbations anymore.
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    Tunable Kerr frequency combs and temporal localized states in time-delayed Gires--Tournois interferometers
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2019) Schelte, Christian; Pimenov, Alexander; Vladimirov, Andrei G.; Javaloyes, Julien; Gurevich, Svetlana V.
    In this Letter we study theoretically a new set-up allowing for the generation of temporal localized states and frequency combs. The setup is compact (a few cm) and can be implemented using established technologies, while offering tunable repetition rates and potentially high power operation. It consists of a vertically emitting micro-cavity, operated in the Gires?Tournois regime, containing a Kerr medium with strong time-delayed optical feedback as well as detuned optical injection. We disclose sets of multistable dark and bright temporal localized states coexisting on their respective bistable homogeneous backgrounds.
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    Directional reversals and multimode dynamics in semiconductor ring lasers
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2013) Pérez-Serrano, Antonio; Javaloyes, Julien; Balle, Salvador
    We investigate the dynamics of longitudinal modes in quantum-well semiconductor ring lasers by means of a spatio-temporal travelling wave model. We report the existence of a novel multimode instability in such a system that provokes a periodic deterministic directional reversal involving jumps between consecutive longitudinal modes. The switching sequence follows the modal frequencies from blue to red, and every modal jump is accompanied by a reversal of the direction of emission. We characterize and analyze such instability via the bifurcation analysis of the full travelling wave model as well as by performing the linear stability analysis of the monochromatic solutions.
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    Spectral delay algebraic equation approach to broad area laser diodes
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2012) Pérez-Serrano, Antonio; Javaloyes, Julien; Balle, Salvador
    In this work, we discuss an efficient modeling approach for the simulation of Broad Area Laser Diodes. Our method is based on the analytical solution in the spectral domain of the paraxial wave equations for the forward and backward slowly varying traveling waves. We show how to extend to the lateral dimension and to the influence of diffractive terms the idea of mesh decimation by recasting traveling wave models into coupled delay algebraic equations, as discussed in [1]. We compare the results of the dynamics obtained with our improved model with the results of a standard traveling wave description in the cases of straight current stripes as well as in the important configuration of high power tapered anti-reflection coated devices. We obtain an excellent agreement and an improvement of the integration time between one and two orders of magnitudes which may alleviate the necessity of using complex parallel codes. We discussed how the method can be further improved to other, more refined descriptions of the active medium and to the inclusion of thermal effects.
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    Multi-channel wavelength conversion using four-wave mixing in semiconductor ring lasers
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2012) Pérez-Serrano, Antonio; Javaloyes, Julien; Balle, Salvador
    We theoretically study all-optical simultaneous wavelength conversion of multiple channels by four-wave mixing in semiconductor ring lasers. Locking the semiconductor ring laser to a holding beam allows to achieve large conversion efficiencies with good signal-tonoise ratio in several channels at multi-Gb/s bit rates. Cross-talk between signals, arising from the peculiar four-wave mixing cascade of modes in semiconductor ring lasers and their cross-gain saturation, is studied in detail. We show that it can be controlled by adjusting the intensity of the holding beam, the bias current of the laser and the number, intensity and wavelength of signals that one wants to convert.