Spontaneous exchange of leader-laggard relationship in mutually coupled synchronized semiconductor lasers

Abstract

We investigate the instantaneous behavior of synchronized temporal wave forms in two mutually coupled semiconductor lasers numerically and experimentally. The temporal wave forms of two lasers are synchronized with a propagation delay time, with one laser oscillating in advance of the other, known as the leader-laggard relationship. The leader-laggard relationship can be determined by measuring the cross-correlation between the two temporal wave forms with the propagation delay time. The leader can be identified when the optical carrier frequency of the leader laser is higher than that of the other laser. However, spontaneous exchange between the leader and laggard lasers can be observed in low-frequency fluctuations by short-term cross-correlation measurements, even for a fixed initial optical frequency detuning. The spontaneous exchange of the leader-laggard relationship originates from alternation of partial optical frequency locking between the two lasers. This observation is analyzed using a phase space trajectory on steady-state solutions for mutually coupled lasers with optical frequency detuning.

Reservoir computing and decision making using laser dynamics for photonic accelerator

“…The spontaneous exchange of the leader-laggard relationship is studied for every coupling delay time. 31) In addition, the leader-laggard relationship can be controlled by changing the initial optical frequencies or coupling strengths. 31) The dynamics of the leader-laggard relationship in the lag synchronization of chaos can be used for solving the multiarmed bandit problem by exploiting its spontaneous probabilistic attributes of laser physics.…”

“…31) In addition, the leader-laggard relationship can be controlled by changing the initial optical frequencies or coupling strengths. 31) The dynamics of the leader-laggard relationship in the lag synchronization of chaos can be used for solving the multiarmed bandit problem by exploiting its spontaneous probabilistic attributes of laser physics. We consider that the spontaneous exchange of the leader laser for every coupling delay time can be useful to alternately select one of the slot machines for efficient exploration.…”

Numerical study on dynamics-dependent synchronization in mutually-coupled lasers with asymmetric feedback

“…7 for r SOA = 1.3. The chaotic attractors are plotted on the coordinates of the optical frequency shift and the carrier density [10,26,27]. In Figs.…”

“…When lasers are mutually coupled, different types of synchronization phenomena of LFF dynamics have been reported. For example, the leader-laggard relationship of lag synchronization has been demonstrated [8][9][10], where the lasers can be synchronized with the time lag depending on the coupling distance between the lasers. This phenomenon can be observed even though the lasers are coupled symmetrically by spontaneous symmetry breaking.…”

Chimera states in hybrid coupled neuron populations

“…Synchronization is widely considered to be essential for the proper functioning of a large variety of natural and artificial systems, ranging from physical experiments to chemical reactions and physiological processes. Prominent examples include communication networks [1,2], coupled lasers [3][4][5][6], Josephson junctions [7,8], oxidation and catalytic surface reactions [9][10][11], power grids [12] as well as circadian oscillators [13,14] and genetic oscillator networks [15][16][17]. Apart from these, synchronization in neural systems has remained a very popular research area during the last decades, because it is widely assumed to be a possible underlying mechanism for various behavioral and cognitive functions, e.g., attention, information processing, and neural control of movement [18][19][20][21][22].…”