Introduction:
The present thesis is devoted to the study of semiconductor lasers subject to delayed optical
feedback and coupling. The complex spectral and dynamical properties of these systems have
been investigated using state-of-the-art telecommunications detection technologies. With such
tools, we have been able to experimentally characterize previously unknown features in our
delay-coupled systems. Along this work, both fundamental and applied results are presented
for the different experiments investigated.
Results:
The first part of the thesis is focusing on the system of the single delayed feedback laser. The
problem of feedback characterization is approached from a time scale perspective, relating the
dynamical regimes to the characteristic frequencies of the delayed feedback laser. We have
empirically found that the ratios of these characteristic frequencies completely determine the
dynamical behavior. This constitutes a model independent approach that can be used, for
example, to test the validity of numerical models that aim at explaining the dynamical behavior
of these lasers. Furthermore, the general extent of our approach is validated by measuring
various laser diodes with distinct characteristics.
Specific properties of the dynamics of the single laser with feedback system have also been
characterized by means of the intensity autocorrelation function. For this purpose, the
experimental autocorrelation is compared with the autocorrelation obtained from a model of a stochastic linear oscillator with delay. The relation between the model parameters and the
experimental system parameters is analyzed and discussed together with the limits of validity
of this approach.
In the second part, systems with two delay-coupled lasers are studied. The phenomenon of
chaos synchronization is explored in two different configurations: a unidirectional coupling
configuration where the delayed feedback laser signal is optically coupled to a second laser,
and a bidirectional scheme of two mutually coupled lasers with self-feedback. In the first
configuration, the relation between the consistency of the dynamics and the synchronizability
with the second laser is studied. In the latter scheme, the robustness of the synchronized state
is characterized against detuning in parameters and noise. The knowledge gained in the
synchronization experiments is used to implement a classical public-channel secure-key
exchange protocol in the bidirectional coupling scheme. This protocol is demonstrated
experimentally, and its advantages and weaknesses are analyzed.
Finally, we present a practical photonic implementation of a dynamical system experiencing two
different delay times depending on the state of the system. The stationary spectral
characteristics of this experimental system are studied and the conditions for the dynamics to
occur in separated states are highlighted. We have also investigated the real-time intensity and
optical spectrum dynamics to demonstrate the existence and properties of state-dependent
delay dynamics. Qualitatively similar properties can be found from a proper numerical model of
this system.
Conclusions:
Altogether, we have presented fundamental and applied aspects of semiconductor lasers
optically coupled with delay. The presented phenomenology is of immediate potential use for a
variety of applications that range from photonics-based reservoir computing to chaos
communications. In addition, the presented fundamental insights can potentially be extended to
other classes of dynamical systems.
Contents:
Resum (iv)
Abstract (vi)
List of Publications (vii)
1 Introduction (1)
1.1 Motivation (1)
1.2 Semiconductor Laser Devices (2)
1.3 Nonlinear Dynamics of Semiconductor Lasers (5)
1.3.1 Delayed Optical Feedback Effects on the Emission of Semiconductor Lasers (6)
1.4 Chaos Synchronization in Optically-Coupled Semiconductor Lasers (11)
1.5 Outline of this Thesis (14)
2 Semiconductor Lasers Subject to Delayed Optical Feedback: Similarity Properties in the
Dynamics (17)
2.1 Introduction (17)
2.1.1 Strong and Weak Chaos Regimes (18)
2.1.2 Chapter Outline (18)
2.1.3 Contributions to the Work in the Present Chapter (19)
2.2 Experimental Methods (19)
2.2.1 Semiconductor Lasers (19)
2.2.2 Feedback Experiments in Fiber-Based Setups (20)
2.2.3 Acquisition Conditions (21)
2.3 Characteristic Frequencies of Delayed Feedback Lasers (21)
2.3.1 Autocorrelation Function of the Intensity Dynamics (24)
2.4 Invariant Dynamics Signature (25)
2.4.1 Physical Mechanism for Weak and Strong Chaos (27)
2.5 Full Rescaling of the Dynamics (30)
2.6 Dynamical Regimes (32)
2.6.1 Low Feedback Strengths (32)
2.6.2 Intermediate Feedback Strengths (34)
2.6.3 High Feedback Strengths (34)
2.7 Comparison with Numerical Modelling (35)
2.8 Similarity Properties in Quantum Dot Lasers (38)
2.8.1 Brief Introduction to Quantum Dot Lasers Particularities (38)
2.8.2 Invariant Dynamics Signature in Quantum-Dot Lasers (40)
2.9 Discussion and Summary (42)
3 Properties of the Autocorrelation Function of a Laser with Feedback (45)
3.1 Introduction (45)
3.1.1 Chapter Outline (46)
3.1.2 Contributions to the Work in the Present Chapter (46)
3.2 Experimental Methods (46)
3.2.1 Experimental Technique to Determine the Delay Time (47)
3.3 Autocorrelation Function of a Linear Stochastic Delay Model (47)
3.4 Comparison of the Autocorrelation Functions of the Laser and the Linear Model (51)
3.5 Limits of Validity of the Linear Approximation (53)
3.6 Parameters Extraction from the Fit of the Autocorrelation Function (56)
3.6.1 Time Delay Extraction (58)
3.7 Summary and Discussion (59)
4 Chaos Synchronization in Delay-Coupled Semiconductor Lasers (61)
4.1 Introduction (61)
4.1.1 Chapter Outline (63)
4.1.2 Contributions to the Work in the Present Chapter (63)
4.2 Experimental Methods (64)
4.2.1 Experimental Setups for Synchronization Experiments (64)
4.2.2 Cross-Correlation Analysis (66)
4.3 Correlations and Synchronization of Unidirectionally Coupled Lasers in Open-Loop
Configuration (66)
4.4 Synchronization of Two Mutually-Coupled Semiconductor Lasers with a Passive Relay (73)
4.4.1 Influence of Spectral Detuning (76)
4.4.2 Isochronous Synchronization Regime (78)
4.4.3 Noise-Induced Desynchronization Events: Bubbling (79)
4.5 Summary and Discussion (86)
5 Bidirectional Secure Key Exchange using Chaotic Semiconductor Lasers (89)
5.1 Introduction (89)
5.1.1 Chapter Outline (93)
5.1.2 Contributions to the Work in the Present Chapter (93)
5.2 Experimental Methods (94)
5.3 Encrypted-Key Distribution Scheme (95)
5.3.1 Simultaneous Bidirectional Key Exchange Protocol (96)
5.3.2 Particularities of the Experimental Setup (96)
5.3.3 Proof of Concept (99)
5.4 Security Analysis of Our Scheme (102)
5.5 Discussion and Summary (106)
6 State-Dependent Delay Dynamics in Semiconductor Lasers (109)
6.1 Introduction (109)
6.1.1 Chapter Outline (111)
6.1.2 Contributions to the Work in the Present Chapter (111)
6.2 Experimental Methods (111)
6.3 Experimental Results (114)
6.4 Numerical Modeling (124)
6.5 Switching Characteristics (127)
6.6 Summary and Discussion (129)
7 Concluding Remarks (131)
A Appendix A (137)
A.1 Laser Sources (137)
A.2 Feedback Experiments in Fiber-Based Setups (140)
A.3 Signal Detection (141)
A.4 List of Instruments and Components (142)
Abbreviations (145)
Bibliography (147)
| Identifer | oai:union.ndltd.org:TDX_UIB/oai:www.tdx.cat:10803/375896 |
| Date | 30 November 2015 |
| Creators | Porte Parera, Javier |
| Contributors | Cornelles Soriano, Miguel, Fischer, Ingo, Universitat de les Illes Balears. Departament de Física |
| Publisher | Universitat de les Illes Balears |
| Source Sets | Universitat de les Illes Balears |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | 163 p., application/pdf |
| Source | TDX (Tesis Doctorals en Xarxa) |
| Rights | ADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs., info:eu-repo/semantics/openAccess |
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