摘要:

This exposition explains the basic ideas and methods of bifurcation analysis, where the rate equation model of an optically injected semiconductor laser is used as an example throughout. Bifurcations of equilibria and periodic orbits that occur when a single parameter is changed are introduced one by one. For each of them we show what the bifurcation actually looks like for the injected laser. The transitons to chaos via period-doublings and the break-up of a torus are explained as well. Finally, a brief discussion points to topics not covered here. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337756

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

We give a review of the most well-known examples of dynamical systems with chaotic dynamics. After a phenomenological introduction, a definition of chaos is ‘deduced’. One of the examples concerns the He´non-attractor, that has only recently been characterized as the closure of a coiling curve. We will explain why it is plausible that this characterization also holds for more realistic cases and, in particular, for periodically forced system. As examples we use the driven damped pendulum and the laser with optical injection. Finally, we indicate some links between chaos and probability. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337757

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

In many areas of engineering and science the mathematical formulation leads to nonlinear problems that are difficult to solve even numerically. Many of the numerical difficulties come from the stiffness of the equations due to the presence of small or large parameters multiplying time derivatives. Very often, the solution exhibits different time scales because of these parameters. It is therefore important to identify them and possibly simplify our equations by applying asymptotic techniques appropriate for multiple scale problems. In this paper, we review a certain number of multiple time scale problems which have appeared for a variety of lasers. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337758

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

For dynamical systems governed by feedback laws, time delays arise naturally in the feedback loop to represent effects due to communication, transmission, transportation or iternia effects. The introduction of time delays in a system of differential equations results in an infinite dimensional state space. We give an introduction to the basic theory of delay equations. After this introduction we illustrate the theory with a local analysis of the Lang-Kobayashi equations describing a laser with delayed optical feedback. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337759

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

A tutorial introduction to the dynamical behavior of lasers is presented. Simple physical pictures explain the essential ingredients that determine the dynamical properties. The relevant dynamical equations are derived for a laser with delayed external optical feedback, possibly spectrally filtered before re-entry into the laser. Focusing on semiconductor lasers the steady-state solutions are derived and discussed as to their stability, whereafter the various different types of dynamics predicted by the model are presented, highlighting Low-Frequency Fluctuations. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337760

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

We numerically study the synchronization of two chaotic semiconductor lasers in amaster-slaveconfiguration. To synchronize the lasers a small amount of the output power from the master laser is injected into the slave laser. We show that the output of the master laser can be used as a chaotic carrier to encode a digital message which can be recovered at the receiver. We also check the quality of the synchronization diagram when the two lasers are slightly different. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337761

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

A hierarchy of theoretical models ranging from microscopic levels of description to effective rate equations is presented in terms of characteristic physical processes of the active semiconductor medium and the light field occurring in space and time. The applicability of the various levels of approximations of the hierarchy to describe the dynamics of spatially extended edge-emitting and vertical-cavity surface-emitting semiconductor lasers is discussed with characteristic results of numerical simulations. The influence of delayed optical feedback on the spatio-temporal dynamics is described. In particular, we show how suitably tailored delayed coherent feedback can be employed for the control of spatio-temporal dynamics. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337762

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The semiconductor laser offers enormous advantages as a practical device in many technological applications because of its very large gain per unit length. This translates into compact size, making it an ideal system for integration into complex integrated opto-electronic systems networks. However, this advantage comes at a price. Achieving large gain in small volumes introduces significant thermal and electrical transport issues. The enormous gain in bandwidth of the laser and the complicated dependence of gain and refractive index on carrier density, plasma and lattice temperature, makes it particularly challenging for study as a nonlinear dynamical system. A systematic, predictive and robust study requires a multi-faceted first-principles approach that combines the microscopic physics of the light-semiconductor medium interaction with the proper resolution of the spatial and temporal degrees of freedom of the running laser. In this lecture, I will stress features that highlight the need to treat the behavior of the laser at this more sophisticated level beyond the simple and well-used phenomenological single or coupled mode models. The picture that will emerge is that, although in many cases the laser may be running nominally as a single longitudinal mode device, the other suppressed modes are still active and can grow under the influence of weak external perturbation. Wide aperture lasers, designed for high power, high brightness applications, are intrinsically dynamically unstable and display multi-longitudinally-moded chaotic filamentation instabilities. After briefly reviewing various analytic approaches to studying spatio-temporal dynamics in semiconductor lasers, I will discuss specific examples of a low-power external cavity device and a variety of high power wide aperture systems. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337763

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

We outline physical models and simulations for suppression of self-focusing and filamentation in large aperture semiconductor lasers. The principal technical objective is to generate multi-watt CW or quasi-CW outputs with nearly diffraction limited beams, suitable for long distance free space transmission, focusing to small spots or coupling to single mode optical fibres. The principal strategies are (a) optimization of facet damage thresholds, (b) reduction of the linewidth enhancement factor which acts as the principal nonlinear optical coefficient, and (c) design of laterally profiled propagation structures in lasers or amplifiers which suppress lateral reflections. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337764

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The dynamics of semiconductor lasers under external influences are examined. In particular, the focus is on two possible configurations: the semiconductor laser under optical injection, and under delayed optical feedback. The injection model for the case of weak injection and large detuning is analyzed and experimental results are used to first determine the parameters that appear in the dynamical equations. A second injection is then used to probe the injection locked system and investigate theoretically and experimentally the response of this system. The stability boundaries of both configurations are analyzed and limit points and Hopf bifurcations points are determined. For the delayed feedback model a large number of external cavity modes can become available to the system for strong feedback and long external cavities, and a series of cascades close to threshold appears to be the route into the Low Frequency Fluctuations. A state that shows similarities with the Low Frequency Fluctuations but appears to be more regular is characterized experimentally and numerically. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1337765

出版商:AIP    

年代:1900

数据来源: AIP