Spatio-Temporal Modeling and Device Optimization of Passively Mode-Locked Semiconductor Lasers

Spatio-Temporal Modeling and Device Optimization of Passively Mode-Locked Semiconductor Lasers PDF

Author: Stefan Meinecke

Publisher: Springer Nature

Published: 2022-03-26

Total Pages: 264

ISBN-13: 3030962482

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This thesis investigates passively mode-locked semiconductor lasers by numerical methods. The understanding and optimization of such devices is crucial to the advancement of technologies such as optical data communication and dual comb spectroscopy. The focus of the thesis is therefore on the development of efficient numerical models, which are able both to perform larger parameter studies and to provide quantitative predictions. Along with that, visualization and evaluation techniques for the rich spatio-temporal laser dynamics are developed; these facilitate the physical interpretation of the observed features. The investigations in this thesis revolve around two specific semiconductor devices, namely a monolithically integrated three-section tapered quantum-dot laser and a V-shaped external cavity laser. In both cases, the simulations closely tie in with experimental results, which have been obtained in collaboration with the TU Darmstadt and the ETH Zurich. Based on the successful numerical reproduction of the experimental findings, the emission dynamics of both lasers can be understood in terms of the cavity geometry and the active medium dynamics. The latter, in particular, highlights the value of the developed simulation tools, since the fast charge-carrier dynamics are generally not experimentally accessible during mode-locking operation. Lastly, the numerical models are used to perform laser design explorations and thus to derive recommendations for further optimizations.

Passively Mode-Locked Semiconductor Lasers

Passively Mode-Locked Semiconductor Lasers PDF

Author: Lina Jaurigue

Publisher: Springer

Published: 2017-06-22

Total Pages: 196

ISBN-13: 3319588745

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This thesis investigates the dynamics of passively mode-locked semiconductor lasers, with a focus on the influence of optical feedback on the noise characteristics. The results presented here are important for improving the performance of passively mode-locked semiconductor lasers and, at the same time, are relevant for understanding delay-systems in general. The semi-analytic results developed are applicable to a broad range of oscillatory systems with time-delayed feedback, making the thesis of relevance to various scientific communities. Passively mode-locked lasers can produce pulse trains and have applications in the contexts of optical clocking, microscopy and optical data communication, among others. Using a system of delay differential equations to model these devices, a combination of numerical and semi-analytic methods is developed and used to characterize this system.

Temporal Cavity Soliton Interaction in Passively Mode-locked Semiconductor Lasers

Temporal Cavity Soliton Interaction in Passively Mode-locked Semiconductor Lasers PDF

Author: Andrei G. Vladimirov

Publisher:

Published: 2023

Total Pages: 0

ISBN-13:

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Weak interaction due to gain saturation and recovery of temporal cavity solitons in a delay differential model of a long cavity semiconductor laser is studied numerically and analytically using an asymptotic approach. It is shown that apart from usual soliton repulsion leading to a harmonic mode-locking regime a soliton attraction is also possible in a laser with nonzero linewidth enhancement factor. It is shown numerically that the attraction can lead either to a soliton merging or to a pulse bound state formation.

Spatial Mode Dynamics in Wide Aperture Semiconductor Lasers

Spatial Mode Dynamics in Wide Aperture Semiconductor Lasers PDF

Author: Jayanta Mukherjee

Publisher:

Published: 2009

Total Pages: 176

ISBN-13:

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Scaling the brightness (spatial coherence) along with output power has been a long-standing problem for semiconductor lasers. The difficulty arises due to complex spatiotemporal modal filamentation associated with light-matter interaction in the non-linear semiconductor lasing medium. This work presents a detailed study of spatiotemporal dynamics in wide aperture semiconductor lasers with the motivation of the identifying factors limiting brightness scaling in the high power regime thereby finding routes to scale the brightness using the unique properties of quantum confined active regions. In this view an opto-electro-thermal model is developed within the Maxwell-Bloch formalism with the capability of describing, frequency, carrier and temperature dependent semiconductor gain and dispersion. The model captures the essential spatiotemporal dynamics in both the thermal and non-thermal regimes and for both homogenous and inhomogeneous broadening in the semiconductor lasing medium. First a steady-state electro-thermal model is developed to simulate the current and heat spreading in the device. Finite element technique (FEM) based simulations are compared with experimental temperature maps obtained from micro-thermographic analysis producing an excellent match resulting in the first concerted study of bulk thermal properties of broad area quantum dot lasers. The thermal model is then used in conjunction with the Maxwell-Bloch based opto-electro-thermal model to obtain pump-dependent modal intensity structure and spatial frequency spectral characteristics. Effect of both homogeneous and inhomogeneous gain broadening is analysed in both the thermal and non-thermal regimes. It is shown via linear stability analysis and high resolution FEM simulations that presence of inhomogeneous gain broadening leads to improved spatial coherence and suppressed filamentation in both thermal and non-thermal regimes. A novel technique based on decoupling of lateral travelling waves corresponding to higher order spatial modes via index-anti-guiding is also described leading to a complete suppression of filamentary modal behaviour. Preliminary experimental results are presented validating the theoretical prediction.

Index to IEEE Publications

Index to IEEE Publications PDF

Author: Institute of Electrical and Electronics Engineers

Publisher:

Published: 1996

Total Pages: 1260

ISBN-13:

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Issues for 1973- cover the entire IEEE technical literature.