Extreme intensity pulses in a semiconductor laser with a short external cavity

We present a numerical study of the pulses displayed by a semiconductor laser with optical feedback in the short cavity regime, such that the external cavity round trip time is smaller than the laser relaxation oscillation period. For certain parameters there are occasional pulses, which are high enough to be considered extreme events. We characterize the bifurcation scenario that gives rise to such extreme pulses and study the influence of noise. We demonstrate intermittency when the extreme pulses appear and hysteresis when the attractor that sustains these pulses is destroyed. We also show that this scenario is robust under the inclusion of noise

Crowd synchrony and quorum sensing in delay-coupled lasers

Crowd synchrony and quorum sensing arise when a large number of dynamical elements communicate with each other via a common information pool. Previous evidence in different fields, including chemistry, biology and civil engineering, has shown that this type of coupling leads to synchronization, when coupling is instantaneous and the number of coupled elements is large enough. Here we consider a situation in which the transmission of information between the system components and the coupling pool is not instantaneous. To that end, we model a system of semiconductor lasers optically coupled to a central laser with a delay. Our results show that, even though the lasers are non-identical due to their distinct optical frequencies, zero-lag synchronization arises. By changing a system parameter, we can switch between two different types of synchronization transition. The dependence of the transition with respect to the delay-coupling parameters is studied.Comment: 4 pages, 4 figure

Controlling the likelihood of rogue waves in an optically injected semiconductor laser via direct current modulation

Extreme and rare events are nowadays the object of intensive research. Rogue waves are extreme waves that appear suddenly in many natural systems, even in apparently calm situations. Here we study numerically the rogue wave dynamics in an optically injected semiconductor laser with external periodic forcing that is implemented via direct modulation of the laser pump current. In the region of optical injection parameters where the laser intensity is chaotic and occasional ultrahigh pulses occur, our aim is to control the system by applying a weak modulation. We find that for an adequate range of frequency and amplitude parameters, the modulation can completely suppress the extreme pulses. We also show that the interplay between modulation and an external source of noise can significantly modify their probability of occurrence. These results can motivate a range of experimental and theoretical investigations in other natural systems.Peer ReviewedPostprint (published version

Double transition to synchronization: A generic emergent transitional behavior in large systems of coupled oscillators

We study a system of M≫ 1 nonidentical laser oscillators coupled with time delay through a central laser oscillator in a star-coupling topology. In the large-M limit we show that this system undergoes novel transitional behavior which represents a new generic type of emergent behavior in large systems of coupled laser oscillators. Specifically, we observe a sequence of two dynamical transitions (“a double transition”). A first transition occurs when the effective threshold of the central oscillators is reached leading to an increase of the order parameter to a level far above the noise level. As the control parameter is raised further a second transition occurs leading to a further increase of the order parameter to a level of order M1/2 above the level achieved past the first transition. A scaling analysis and numerical experiments reveal the underlying mechanism of this scenario. We suggest that double transitions, discovered here in the context of a specific system, are expected to occur in diverse situations involving large coupled-oscillator networks

Multi-stability and transient chaotic dynamics in semiconductor lasers with time-delayed optical feedback

We investigate numerically the chaotic transient dynamics of a semiconductor laser with time-delayed optical feedback. This transient behavior is seen in the low-frequency fluctuations (LFF) regime ocurring when the laser is pumped close to thereshold and is subjected to moderate feedback strengths. We characterize the transient dynamics in terms of its duration, the time intervals between consecutive dropouts, and the total in each transient event. We statistically analyze these quantities as a function of the noise strength and other system parameters related to different nonlinear mechanisms of light-matter interaction inside the laser active medium.Peer ReviewedPostprint (published version

Multi-stability and transient chaotic dynamics in semiconductor lasers with time-delayed optical feedback

We investigate numerically the chaotic transient dynamics of a semiconductor laser with time-delayed optical feedback. This transient behavior is seen in the low-frequency fluctuations (LFF) regime ocurring when the laser is pumped close to thereshold and is subjected to moderate feedback strengths. We characterize the transient dynamics in terms of its duration, the time intervals between consecutive dropouts, and the total in each transient event. We statistically analyze these quantities as a function of the noise strength and other system parameters related to different nonlinear mechanisms of light-matter interaction inside the laser active medium.Peer Reviewe

Multi-stability and transient chaotic dynamics in semiconductor lasers with time-delayed optical feedback

We investigate numerically the chaotic transient dynamics of a semiconductor laser with time-delayed optical feedback. This transient behavior is seen in the low-frequency fluctuations (LFF) regime ocurring when the laser is pumped close to thereshold and is subjected to moderate feedback strengths. We characterize the transient dynamics in terms of its duration, the time intervals between consecutive dropouts, and the total in each transient event. We statistically analyze these quantities as a function of the noise strength and other system parameters related to different nonlinear mechanisms of light-matter interaction inside the laser active medium.Peer Reviewe

Extreme intensity pulses in a semiconductor laser with a short external cavity

We present a numerical study of the pulses displayed by a semiconductor laser with optical feedback in the short-cavity regime, such that the external cavity round-trip time is shorter than the laser relaxation oscillation period. For certain parameters there are occasional pulses, which are high enough to be considered extreme events. We characterize the bifurcation scenario that gives rise to such extreme pulses and study the influence of noise. We demonstrate intermittency when the extreme pulses appear and hysteresis when the attractor that sustains these pulses is destroyed. We also show that this scenario is robust under the inclusion of noise.Peer Reviewe