Dynamic analysis and continuous control of semiconductor lasers (original) (raw)
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Dynamics, bifurcations and chaos in coupled lasers
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2008
Experiments and numerical modelling on two different class B lasers that are subjected to external optical light injection are presented. This presentation includes ways of measuring the changes in the laser output, how to numerically describe the systems and how to construct diagrams of the dynamical states in the plane frequency detuning between lasers and injection strength. The scenarios for the semiconductor laser include an area of frequency locking and islands of chaotic behaviour embedded in and mixed with periodic doubling regimes. Using a rate equation model, the largest Lyapunov exponent is calculated as a measure of the stability of equilibriums and the amount of chaos in chaotic regimes. In the solid-state laser case, different dynamical regions were clearly observed. The found boundaries were identified experimentally, using an identification method, and numerically, from bifurcation analysis, as Hopf, saddle-node, period-doubling and torus bifurcations.
Observations on the dynamics of external cavity semiconductor lasers
Optik, 2012
Dynamics of external cavity semiconductor lasers is known to be a complex and uncontrollable phenomenon. Due to the lack of experimental studies on the nature of the external cavity semiconductor lasers, there is a need to theoretically clarify laser dynamics. The stability of laser dynamics in the present paper, is analyzed through plotting the Lyapunov exponent spectra, bifurcation diagrams, phase portrait and electric field intensity time series. The analysis is preformed with respect to applied feedback phase C p , feedback strength Á and the pump current of the laser. The main argument of the paper is to show that the laser dynamics can not be accounted for through simply a bifurcation diagram and single-control parameter. The comparison of the obtained results provides a very detailed picture of the qualitative changes in laser dynamics.
Experimental route to chaos of an external-cavity semiconductor laser
Physical Review A, 2015
We report experimental bifurcation diagrams of a semiconductor laser, biased well above threshold, subjected to external optical feedback. As feedback is increased, we see a quasiperiodic route to chaos interrupted by several windows of periodicity corresponding to limit cycles, differing in frequency by multiples of the external-cavity free-spectral range that have developed around external-cavity modes (ECMs) whose frequency is slightly larger than that of the solitary laser. Successive windows correspond to the transition between two limit cycles either on the same or neighboring ECMs. For larger feedback, the laser operates in a chaotic regime around numerous negatively shifted external-cavity modes. These experimental observations detail the bifurcations leading to fully developed chaos in this system, and further provide detailed insight on the standard theoretical framework applied to these lasers.
Experimental Evidence of Chaotic Resonance in Semiconductor Laser
Baghdad Science Journal, 2021
In this paper, an experimental study has been conducted regarding the indication of resonance in chaotic semiconductor laser. Resonant perturbations are effective for harnessing nonlinear oscillators for various applications such as inducing chaos and controlling chaos. Interesting results have been obtained regarding to the effect of the chaotic resonance by adding the frequency on the systems. The frequency changes nonlinear dynamical system through a critical value, there is a transition from a periodic attractor to a strange attractor. The amplitude has a very relevant impact on the system, resulting in an optimal resonance response for appropriate values related to correlation time. The chaotic system becomes regular under a moderate frequencies or amplitudes. These dynamics of the laser output are analyzed by time series, FFT and bifurcation diagram as a result.
Chaotic transitions and low-frequency fluctuations in semiconductor lasers with optical feedback
Physica D: Nonlinear Phenomena, 2000
This paper examines the dynamical origin of low-frequency fluctuations (LFFs) in semiconductor lasers subject to timedelayed optical feedback. In particular, we study chaotic transitions leading to the onset of LFFs by numerical integration of Lang-Kobayashi equations for a laser pumped near threshold. We construct a bifurcation analysis scheme that enables the classification of the different operation regimes of the laser. We use the scheme to study the coexistence of the LFFs and stable emission on the maximum gain mode (MGM), which was the subject of recent experiments [T. Heil, I. Fischer, W. Elsäßer, Phys. Rev. A 60 (1999) 634]. Our computations suggest that as the feedback level increases, the regime of sustained LFFs alternates with regions of transient LFFs, where the laser can achieve stabilization on the MGM. Exploration of the parameter space reveals strong dependence of the structure of the LFF dynamics and the coexistence regime on the value of the linewidth enhancement factor. : S 0 1 6 7 -2 7 8 9 ( 0 0 ) 0 0 1 0 7 -X
THE NONLINEAR GAIN AND THE ROUTE TO CHAOS IN SEMICONDUCTOR LASER WITH OPTICAL FEEDBACK
TJPRC, 2013
Influence of nonlinear gain on the operations and route-to-chaos of semiconductor laser subject to wide range of optical feedback are investigated. The simulation is performed based on numerical solution of an improved time delay model, which is applicable under any arbitrary strength of feedback. The route-to-chaos and the operations of laser are classified in terms of the bifurcation diagrams of the photon number at each feedback rate. The simulation results show that, inclusion of nonlinear gain in the rate equations cause significant changes in the route-to-chaos and operations of the laser. The value of the feedback rate at which the transition from continues wave to periodic oscillation or chaos state occur increase, as the intensity of the nonlinear gain is increased. Under strong feedback and by increasing the values of the nonlinear gain the operation of the laser changes from chaos operation to periodic oscillation or continues wave operation depending on feedback strength
TJPRC, 2013
This paper investigates influence of nonlinear gain on the dynamics and onset of chaos (route to chaos) of semiconductor laser and associated operation states over a wide range of optical feedback and injection current. The study is based on numerical solutions of an improved time delay model of optical feedback. The simulation results show that nonlinear gain causes significant changes in the route-to-chaos and the laser states and dynamics. The feedback strength at which the laser transits from continues wave to periodic oscillation or to chaos increases with the increase in the nonlinear gain. Under strong feedback, the increase in nonlinear gain causes change of chaotic dynamics to periodic oscillations or continues wave operation depending on feedback strength. At higher levels of the injection current, nonlinear gain stabilizes the laser operation stimulating the laser to operate in continues wave. We believe that, the instability of the laser diode can be reduced by increasing the nonlinear gain parameter, Optical feedback strength and increasing the injection current ratio to values far from the threshold, which helps to design a laser diode with high static and dynamic performance.
Chaos modulation in semiconductor laser with optoelectronic feedback
IOP Conference Series: Materials Science and Engineering
The experimental and numerical study of chaos modulation will be presented in two stats, first, when the frequency of the external perturbation is varied, secondly, when the amplitude of this perturbation is changed. The dynamics of the laser output are analyzed by Fast Fourier Transformation, attractors and bifurcation Diagram. Some frequencies could be hidden other appeared, when the frequencies are hidden, the communication link considered as secure.