Stable phase-locking of an external-cavity diode laser subjected to external optical injection
TL;DR: In this paper, the locking phenomena arising when an external-cavity diode laser is subjected to optical injection from another uncontrolled diode, and the system stability is investigated as a function of coupled cavity time delay and the optical injection strength.
Abstract: We analyse the locking phenomena arising when an external-cavity diode laser is subjected to optical injection from another uncontrolled diode laser. The system stability is investigated as a function of coupled cavity time delay and the optical injection strength. Different regimes, spanning from 'in-phase locking' to 'out-of-phase locking' with ultimate amplitude death of low-frequency fluctuations/pulsations, are described experimentally as well as numerically for weak to moderate injection. Qualitative agreements between numerically and experimentally observed results for amplitude quenching are shown. Numerical studies describe the shifting of phase-flip bifurcation as the optical injection strength is varied for a particular time delay. Stable phase-locking behaviours, which are desired from the point of view of practical applications, are observed numerically in a wide range of control parameter space.
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TL;DR: In this paper, the authors discuss the most representative examples of hidden attractors, discuss their theoretical properties and experimental observations, and also describe numerical methods which allow identification of the hidden attractor.
569 citations
TL;DR: In this article, two structurally distinct oscillation quenching types: oscillation (O D ) and amplitude death (A D ) are distinguished, and the importance for their correct identification from the aspect of theory as well as of applications is demonstrated.
312 citations
Additional excerpts
...it can lead to stabilization in case of coupled lasers [32,33])....
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...Thus, this behavior is characteristic and has been observed for a wide range of natural and manmade systems, ranging from climate systems [34], lasers [35,32,33], electronic circuits [36,37], systems exhibiting chaotic dynamics [38,39], chemical systems [8,40], neurons [41,42], biological networks [43–45], etc....
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...Moreover, it has been shown that the IHSS (OD) can be related as a background mechanism of cellular differentiation [55,56], whereas AD is mainly used as a stabilization control in physical or chemical systems [32,33]....
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TL;DR: The characteristics of the different coupling strategies and scenarios that lead to amplitude death in a variety of different situations are discussed, and several open issues and challenging problems for further study are drawn attention.
Abstract: When nonlinear dynamical systems are coupled, depending on the intrinsic dynamics and the manner in which the coupling is organized, a host of novel phenomena can arise. In this context, an important emergent phenomenon is the complete suppression of oscillations, formally termed amplitude death (AD). Oscillations of the entire system cease as a consequence of the interaction, leading to stationary behavior. The fixed points that the coupling stabilizes can be the otherwise unstable fixed points of the uncoupled system or can correspond to novel stationary points. Such behaviour is of relevance in areas ranging from laser physics to the dynamics of biological systems. In this review we discuss the characteristics of the different coupling strategies and scenarios that lead to AD in a variety of different situations, and draw attention to several open issues and challenging problems for further study.
231 citations
TL;DR: In this article, a plethora of novel chimera patterns arise if one goes beyond the Kuramoto phase oscillator model, which consist of coexisting spatial domains of coherent and incoherent dynamics in networks of identical oscillators.
Abstract: We review chimera patterns, which consist of coexisting spatial domains of coherent (synchronized) and incoherent (desynchronized) dynamics in networks of identical oscillators. We focus on chimera states involving amplitude as well as phase dynamics, complex topologies like small-world or hierarchical (fractal), noise, and delay. We show that a plethora of novel chimera patterns arise if one goes beyond the Kuramoto phase oscillator model. For the FitzHugh-Nagumo system, the Van der Pol oscillator, and the Stuart-Landau oscillator with symmetry-breaking coupling various multi-chimera patterns including amplitude chimeras and chimera death occur. To test the robustness of chimera patterns with respect to changes in the structure of the network, regular rings with coupling range R, small-world, and fractal topologies are studied. We also address the robustness of amplitude chimera states in the presence of noise. If delay is added, the lifetime of transient chimeras can be drastically increased.
209 citations
TL;DR: In this article, the authors discuss the characteristics of different coupling strategies and scenarios that lead to amplitude death in a variety of different situations, and draw attention to several open issues and challenging problems for further study.
206 citations
References
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TL;DR: In this paper, the effects of external optical feedback on the semiconductor laser properties have been examined, i.e., return of a portion of the laser output from a reflector external to the laser cavity.
Abstract: Influences on the semiconductor laser properties of external optical feedback, i.e., return of a portion of the laser output from a reflector external to the laser cavity, have been examined. Experimental observations with a single mode laser is presented with analysis based on a compound cavity laser model, which has been found to explain essential features of the experimental results. In particular, it has been demonstrated that a laser with external feedback can be multistable and show hysteresis phenomena, analogous to those of non-linear Fabry-Perot resonator. It has also been shown that the dynamic properties of injection lasers are significantly affected by external feedback, depending on interference conditions between returned light and the field inside the laser diode.
2,462 citations
TL;DR: Experimental observations of time-delay-induced amplitude death in two coupled nonlinear electronic circuits that are individually capable of exhibiting limit-cycle oscillations are described and the existence of multiply connected death islands in the parameter space of coupling strength and time delay for coupled identical oscillators is established.
Abstract: We investigate the dynamical behavior of two limit cycle oscillators that interact with each other via time delayed coupling and find that time delay can lead to amplitude death of the oscillators even if they have the same frequency. We demonstrate that this novel regime of amplitude ``death'' also exists for large collections of coupled identical oscillators and provide quantitative measures of this death region in the parameter space of coupling strength and time delay. Its implication for certain biological and physical applications is also pointed out.
499 citations
TL;DR: In this paper, a theoretical and experimental investigation of injection locking of semiconductor lasers is presented, taking into account the dependence of refractive index on the carrier density expressed by the linewidth enhancement factor α.
Abstract: We present a theoretical and experimental investigation of injection locking of semiconductor lasers. The theoretical analysis takes into account the dependence of refractive index on the carrier density expressed by the linewidth enhancement factor α. Locking conditions and dynamic stability are analyzed. The nonzero value of α results in an increased locking bandwidth, where only part of the range corresponds to a dynamically stable state. Asymmetric characteristics are obtained for the locked power and phase as a function of frequency detuning between the master and slave laser. Outside the stable range, light injection gives rise to beat phenomena and intensity pulsations. The theoretical results were confirmed by experiments on 830 nm CSP lasers and 1.3 μm BH lasers. The experiments include the first measurements of locking bandwidth characteristics reported for 1.3 μm lasers. Power spectra are recorded under locked and near-locked conditions and compared with theory. The 1.3 μm lasers are found to have a better dynamic stability than 830 nm lasers. Even so, the stability problems may exclude the particular application of injection locking where phase modulation is generated for coherent transmission.
432 citations
TL;DR: This work indicates the possibility of synchronizing hyperchaotic chaos with just one transmitted sign and unmasking signal process techniques which work well for simple chaotic system.
Abstract: We propose a method for encrypting a signal within the high dimensional chaotic fluctuations of the wavelength from a delayed feedback tunable laser diode. Decoding is performed remotely by using a slave laser diode fully synchronized with the master one. No additional synchronization channel is required.
388 citations
TL;DR: The results give evidence for subnanosecond coupling-induced synchronized chaotic dynamics in conjunction with a spontaneous symmetry-breaking, and a well-defined time lag between the dynamics of the two lasers, and an asymmetric physical role of the subsystems.
Abstract: We present experimental and numerical investigations of the dynamics of two device-identical, optically coupled semiconductor lasers exhibiting a delay in the coupling. Our results give evidence for subnanosecond coupling-induced synchronized chaotic dynamics in conjunction with a spontaneous symmetry-breaking: we find a well-defined time lag between the dynamics of the two lasers, and an asymmetric physical role of the subsystems. We demonstrate that the leading laser synchronizes its lagging counterpart, whereas the synchronized lagging laser drives the coupling-induced instabilities.
371 citations