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- ItemConvective Nozaki-Bekki holes in a long cavity OCT laser(Washington, DC : Soc., 2019) Slepneva, Svetlana; O'Shaughnessy, Ben; Vladimirov, Andrei G.; Rica, Sergio; Viktorov, Evgeny A.; Huyet, GuillaumeWe show, both experimentally and theoretically, that the loss of coherence of a long cavity optical coherence tomography (OCT) laser can be described as a transition from laminar to turbulent flows. We demonstrate that in this strongly dissipative system, the transition happens either via an absolute or a convective instability depending on the laser parameters. In the latter case, the transition occurs via formation of localised structures in the laminar regime, which trigger the formation of growing and drifting puffs of turbulence. Experimentally, we demonstrate that these turbulent bursts are seeded by appearance of Nozaki-Bekki holes, characterised by the zero field amplitude and π phase jumps. Our experimental results are supported with numerical simulations based on the delay differential equations model.
- ItemAn optically injected mode locked laser(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2010) Rebrova, Natalia; Huyet, Guillaume; Rachinskii, Dmitrii; Vladimirov, Andrei G.We study analytically and numerically a delay differential model of a passively mode-locked semiconductor laser subjected to a single frequency coherent injection. The width of the locking cone is calculated asymptotically in the limit of small injection and compared to that obtained by direct numerical integration of the model equations. The dependence of the locking cone on the laser parameters is discussed
- ItemEffect of chromatic dispersion on multimode laser dynamics: Delay differential model(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2016) Vladimirov, Andrei G.; Huyet, Guillaume; Pimenov, AlexanderA set of differential equations with distributed delay is derived for modeling of multimode ring lasers with intracavity chromatic dispersion. Analytical stability analysis of continuous wave regimes is performed and it is demonstrated that sufficiently strong anomalous dispersion can destabilize these regimes.
- ItemDelayed feedback control of self-mobile cavity solitons(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2013) Pimenov, Alexander; Vladimirov, Andrei G.; Gurevich, Svetlana V.; Panajotov, Krassimir; Huyet, Guillaume; Tlidi, MustaphaControl of the motion of cavity solitons is one the central problems in nonlinear optical pattern formation. We report on the impact of the phase of the time-delayed optical feedback and carrier lifetime on the self-mobility of localized structures of light in broad area semiconductor cavities. We show both analytically and numerically that the feedback phase strongly affects the drift instability threshold as well as the velocity of cavity soliton motion above this threshold. In addition we demonstrate that non-instantaneous carrier response in the semiconductor medium is responsible for the increase in critical feedback rate corresponding to the drift instability.
- ItemTurbulent coherent structures in a long cavity semiconductor laser near the lasing threshold(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2020) Gowda, Uday; Roche, Amy; Pimenov, Alexander; Vladimirov, Andrei G.; Slepneva, Svetlana; Viktorov, Evgeny A.; Huyet, GuillaumeWe report on the formation of novel turbulent coherent structures in a long cavity semiconductor laser near the lasing threshold. Experimentally, the laser emits a series of power dropouts within a roundtrip and the number of dropouts per series depends on a set of parameters including the bias current. At fixed parameters, the drops remain dynamically stable, repeating over many roundtrips. By reconstructing the laser electric field in the case where the laser emits one dropout per round trip and simulating its dynamics using a time-delayed model, we discuss the reasons for long-term sustainability of these solutions. We suggest that the observed dropouts are closely related to the coherent structures of the cubic complex Ginzburg-Landau equation.
- ItemBifurcation structure of a swept source laser(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2020) Kovalev, Anton V.; Dmitriev, Pavel S.; Vladimirov, Andrei G.; Pimenov, Alexander; Huyet, Guillaume; Viktorov, Evgeniy A.We numerically analyze a delay differential equation model of a short-cavity semiconductor laser with an intracavity frequency swept filter and reveal a complex bifurcation structure responsible for the asymmetry of the output characteristics of this laser. We show that depending on the direction of the frequency sweep of a narrowband filter, there exist two bursting cycles determined by different parts of a continuous-wave solutions branch.
- ItemBistability and hysteresis in an optically injected two-section semiconductor laser(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2014) Pimenov, Alexander; Viktorov, Evgeniy A.; Hegarty, Stephen P.; Habruseva, Tatiana; Huyet, Guillaume; Rachinskii, Dmitrii; Vladimirov, Andrei G.The effect of coherent single frequency injection on two-section semiconductor lasers is studied numerically using a model based on a set of delay differential equations. The existence of bistability between different CW and non-stationary regimes of operation is demonstrated in the case of sufficiently large linewidth enhancement factors.
- ItemDynamical regimes in a class A model of a nonlinear mirror mode-locked laser(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2019) Vladimirov, Andrei G.; Kovalev, Anton V.; Viktorov, Evgeny A.; Rebrova, Natalia; Huyet, GuillaumeUsing a simple delay differential equation model we study theoretically the dynamics of a unidirectional class-A ring laser with a nonlinear amplifying loop mirror. We perform analytical linear stability analysis of the CW regimes in the large delay limit and demonstrate that these regimes can be destabilized via modulational and Turing-type instabilities, as well as by a bifurcation leading to the appearance of square-waves. We investigate the formation of square-waves and mode-locked pulses in the system. We show that mode-locked pulses are very asymmetric with exponential decay of the trailing and superexponential growth of the leading edge. We discuss asymmetric interaction of these pulses leading to a formation of harmonic mode-locked regimes.
- ItemDispersive time-delay dynamical systems(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2016) Pimenov, Alexander; Slepneva, Svetlana; Huyet, Guillaume; Vladimirov, Andrei G.We present a theoretical approach to model the dynamics of a dispersive nonlinear system using a set of delay differential equations with distributed delay term. We illustrate the use of this approach by considering a frequency swept laser comprising a semiconductor optical amplifier (SOA), a tunable bandpass filter and a long dispersive fiber delay line. We demonstrate that this system exhibits a rich spectrum of dynamical behaviors which are in agreement with the experimental observations. In particular, the multimode modulational instability observed experimentally in the laser in the anomalous dispersion regime and leading to a turbulent laser output was found analytically in the limit of large delay time.
- ItemA delay differential equation NOLM--NALM mode-locked laser model(Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2021) Vladimirov, Andrei G.; Suchkov, Sergey; Huyet, Guillaume; Turitsyn, Sergey K.Delay differential equation model of a NOLM-NALM mode-locked laser is developed that takes into account finite relaxation rate of the gain medium and asymmetric beam splitting at the entrance of the nonlinear mirror loop. Asymptotic linear stability analysis of the continuous wave solutions performed in the limit of large delay indicates that in a class-B laser flip instability leading to a period doubling cascade and development of square-wave patterns can be suppressed by a short wavelength modulational instability. Numerically it is shown that the model can demonstrate large windows of regular fundamental and harmonic mode-locked regimes with single and multiple pulses per cavity round trip time separated by domains of irregular pulsing.