Download or read book Design simulation and analysis of laterally longitudinally non uniform edge emitting GaAs based diode lasers Band 73 written by Jan-Philipp Koester and published by Cuvillier Verlag. This book was released on 2023-09-19 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edge-emitting quantum-well diode lasers based on GaAs combine a high conversion efficiency, a wide range of emission wavelengths covering a span from 630 nm to 1180 nm, and the ability to achieve high output powers. The often used longitudinal-invariant Fabry-Pérot-type resonators are easy to design but often lead to functionality or performance limitations. In this work, the application of laterally-longitudinally non-uniform resonator configurations is explored as a way to reduce unwanted and performance-limiting effects. The investigations are carried out on existing and entirely newly developed laser designs using dedicated simulation tools. These include a sophisticated time-dependent laser simulator based on a traveling-wave model of the optical fields in the lateral-longitudinal plane and a Maxwell solver based on the eigenmode expansion method for the simulation of passive waveguides. Whenever possible, the simulation results are compared with experimental data. Based on this approach, three fundamentally different laser types are investigated: • Dual-wavelength lasers emitting two slightly detuned wavelengths around 784 nm out of a single aperture • Ridge-waveguide lasers with tapered waveguide and contact layouts that emit light of a wavelength of around 970 nm • Broad-area lasers with slightly tapered contact layouts emitting at 910 nm The results of this thesis underline the potential of lateral-longitudinal non-uniform laser designs to increase selected aspects of device performance, including beam quality, spectral stability, and output power.
Download or read book Design Simulation and Analysis of Laterally longitudinally Non uniform Edge emitting GaAs based Diode Lasers written by Jan-Philipp Koester and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Spatio Temporal Phenomena in High Brightness Diode Lasers using Numerical Simulations written by Anissa Zeghuzi and published by Cuvillier Verlag. This book was released on 2020-10-22 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Broad-area lasers are edge-emitting semiconductor lasers with a wide lateral emission aperture. This feature enables high output powers but also diminishes the lateral beam quality and results in their inherently non-stationary behavior. Research in the area is driven by application, and the main objective is to increase the brightness, which includes both output power and lateral beam quality. To understand the underlying spatio-temporal phenomena and to apply this knowledge in order to reduce costs for brightness optimization, a self-consistent simulation tool taking all essential processes into account is vital. Firstly, in this work a quasi-three-dimensional opto-electronic and thermal model is presented that describes essential qualitative characteristics of real devices well. Time-dependent traveling-wave equations are utilized to characterize the inherently non-stationary optical fields, which are coupled to dynamic rate equations for the excess carriers in the active region. This model is extended by an injection-current-density model to accurately include lateral current spreading and spatial hole burning. Furthermore, a temperature model is presented that includes short-time local heating near the active region as well as the formation of a stationary temperature profile. Secondly, the reasons of brightness degradation, i.e. the origins of power saturation and the spatially modulated field profile, are investigated. And lastly, designs that mitigate those effects limiting the lateral brightness under pulsed and continuous-wave operation are discussed. Amongst those designs a novel “chessboard laser” is presented that utilizes longitudinal-lateral gain-loss modulation and an additional phase tailoring to obtain a very low far-field divergence.
Download or read book Epitaxial Design Optimizations for Increased Efficiency in GaAs Based High Power Diode Lasers written by Thorben Kaul and published by Cuvillier Verlag. This book was released on 2021-04-09 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents progress in the root-cause analysis of power saturation mechanisms in continuous wave (CW) driven GaAs-based high-power broad area diode lasers operated at 935 nm. Target is to increase efficiency at high optical CW powers by epitaxial design. The novel extreme triple asymmetric (ETAS) design was developed and patented within this work to equip diode lasers that use an extremely thin p-waveguide with a high modal gain. An iterative variation of diode lasers employing ETAS designs was used to experimentally clarify the impact of modal gain on the temperature dependence of internal differential quantum efficiency (IDQE) and optical loss. High modal gain leads to increased free carrier absorption from the active region. However, less power saturation is observed, which must then be attributed to an improved temperature sensitivity of the IDQE. The effect of longitudinal spatial hole burning (LSHB) leads to above average non-linear carrier loss at the back facet of the device. At high CW currents the junction temperature rises. Therefore, not only the asymmetry of the carrier profile increases but also the average carrier density in order to compensate for the decreased material gain and increased threshold gain. This carrier non-pinning effect above threshold is found in this work to enhance the impact of LSHB already at low currents, leading to rapid degradation of IDQE with temperature. This finding puts LSHB into a new context for CW-driven devices as it emphasizes the importance of low carrier densities at threshold. The carrier density was effectively reduced by applying the novel ETAS design. This enabled diode lasers to be realized that show minimized degradation of IDQE with temperature and therefore improved performance in CW operation.
Download or read book Simulation and Design of a Compact GaAs Based Tunable Dual wavelength Diode Laser System written by Jan-Philipp Koester and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present our design of a compact, integrated and tunable dual-wavelength diode laser system emitting around 785 nm, which is of interest for several applications like Raman spectroscopy and the generation of THz radiation. To achieve a more compact device compared to previous GaAs based designs two etch depths are realized, leading to shallowly etched ridge waveguides in regions were optical gain is applied and deeply etched waveguides used to enable compact integrated waveguide components. The device parameters are optimized using a numerically efficient simulation tool for passive waveguides. Subsequently, the entire laser system is further analyzed applying a sophisticated traveling-wave equation based model for active devices giving access to internal intensity and carrier density distributions. It is shown that active laser simulations all-passive simulation.
Download or read book Semiconductor Laser Engineering Reliability and Diagnostics written by Peter W. Epperlein and published by John Wiley & Sons. This book was released on 2013-01-25 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference book provides a fully integrated novel approach to the development of high-power, single-transverse mode, edge-emitting diode lasers by addressing the complementary topics of device engineering, reliability engineering and device diagnostics in the same book, and thus closes the gap in the current book literature. Diode laser fundamentals are discussed, followed by an elaborate discussion of problem-oriented design guidelines and techniques, and by a systematic treatment of the origins of laser degradation and a thorough exploration of the engineering means to enhance the optical strength of the laser. Stability criteria of critical laser characteristics and key laser robustness factors are discussed along with clear design considerations in the context of reliability engineering approaches and models, and typical programs for reliability tests and laser product qualifications. Novel, advanced diagnostic methods are reviewed to discuss, for the first time in detail in book literature, performance- and reliability-impacting factors such as temperature, stress and material instabilities. Further key features include: practical design guidelines that consider also reliability related effects, key laser robustness factors, basic laser fabrication and packaging issues; detailed discussion of diagnostic investigations of diode lasers, the fundamentals of the applied approaches and techniques, many of them pioneered by the author to be fit-for-purpose and novel in the application; systematic insight into laser degradation modes such as catastrophic optical damage, and a wide range of technologies to increase the optical strength of diode lasers; coverage of basic concepts and techniques of laser reliability engineering with details on a standard commercial high power laser reliability test program. Semiconductor Laser Engineering, Reliability and Diagnostics reflects the extensive expertise of the author in the diode laser field both as a top scientific researcher as well as a key developer of high-power highly reliable devices. With invaluable practical advice, this new reference book is suited to practising researchers in diode laser technologies, and to postgraduate engineering students.
Download or read book Surface Emitting Semiconductor Lasers and Arrays written by Gary A. Evans and published by . This book was released on 1993 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews all the basic types of surface emitting semiconductor lasers, including vertical cavity, etched-mirror integrated beam deflectors and grating out-coupled devices. The book also addresses such topics as edge-emitting arrays, thermal management and coherence.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1994 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fibre Optic Communication Devices written by Norbert Grote and published by Springer Science & Business Media. This book was released on 2001-01-26 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optoelectronic devices and fibre optics are the basis of cutting-edge communication systems. This monograph deals with the various components of these systems, including lasers, amplifiers, modulators, converters, filters, sensors, and more.
Download or read book VCSELs written by Rainer Michalzik and published by Springer. This book was released on 2012-10-16 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: The huge progress which has been achieved in the field is covered here, in the first comprehensive monograph on vertical-cavity surface-emitting lasers (VCSELs) since eight years. Apart from chapters reviewing the research field and the laser fundamentals, there are comprehensive updates on red and blue emitting VCSELs, telecommunication VCSELs, optical transceivers, and parallel-optical links for computer interconnects. Entirely new contributions are made to the fields of vectorial three-dimensional optical modeling, single-mode VCSELs, polarization control, polarization dynamics, very-high-speed design, high-power emission, use of high-contrast gratings, GaInNAsSb long-wavelength VCSELs, optical video links, VCSELs for optical mice and sensing, as well as VCSEL-based laser printing. The book appeals to researchers, optical engineers and graduate students.
Download or read book Ceramic Lasers written by Akio Ikesue and published by Cambridge University Press. This book was released on 2013-05-23 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until recently, ceramic materials were considered unsuitable for optics due to the numerous scattering sources, such as grain boundaries and residual pores. However, in the 1990s the technology to generate a coherent beam from ceramic materials was developed, and a highly efficient laser oscillation was realized. In the future, the technology derived from the development of the ceramic laser could be used to develop new functional passive and active optics. Co-authored by one of the pioneers of this field, the book describes the fabrication technology and theoretical characterization of ceramic material properties. It describes novel types of solid lasers and other optics using ceramic materials to demonstrate the application of ceramic gain media in the generation of coherent beams and light amplification. This is an invaluable guide for physicists, materials scientists and engineers working on laser ceramics.
Download or read book Semiconductor Detector Systems written by Helmuth Spieler and published by OUP Oxford. This book was released on 2005-08-25 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor sensors patterned at the micron scale combined with custom-designed integrated circuits have revolutionized semiconductor radiation detector systems. Designs covering many square meters with millions of signal channels are now commonplace in high-energy physics and the technology is finding its way into many other fields, ranging from astrophysics to experiments at synchrotron light sources and medical imaging. This book is the first to present a comprehensive discussion of the many facets of highly integrated semiconductor detector systems, covering sensors, signal processing, transistors and circuits, low-noise electronics, and radiation effects. The diversity of design approaches is illustrated in a chapter describing systems in high-energy physics, astronomy, and astrophysics. Finally a chapter "Why things don't work" discusses common pitfalls. Profusely illustrated, this book provides a unique reference in a key area of modern science.
Download or read book Integrated Optoelectronics written by Karl J. Ebeling and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: The English edition is based upon the second edition of the German version of the book. The author would like to thank Mr. A.H. Armstrong for providing the basic English manuscript of the text, his critical reading, and valuable comments. Thanks are also due to Mrs. A. Demmer, Mr. J. Matern, Mrs. B. Titze and Mrs. S. Pfetsch for preparing the camera ready manuscript and the figures. Springer Verlag has generously supported the project and cooperating with them has been a great pleasure. Ulm, April 1992 K.J. Ebeling Preface to the First German Edition This book is a comprehensive introduction to waveguide optics and photonics in semiconductor crystals. Interest is centered on integrated optoelectronic devices for the transmission and processing of optical signals. These optical communi cations engineering devices are becoming increasingly important for optical disk storage systems, for optical chip-chip interconnections and of course for optical fiber transmission and exchange.
Download or read book Handbook of Distributed Feedback Laser Diodes Second Edition written by Geert Morthier and published by Artech House. This book was released on 2013-09-01 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the first edition of this book was published in 1997, the photonics landscape has evolved considerably and so has the role of distributed feedback (DFB) laser diodes. Although tunable laser diodes continue to be introduced in advanced optical communication systems, DFB laser diodes are still widely applied in many deployed systems. This also includes wavelength tunable DFB laser diodes and DFB laser diode arrays, usually integrated with intensity or phase modulators and semiconductor optical amplifiers. This valuable resource gives professionals a comprehensive description of the different effects that determine the behavior of a DFB laser diode. Special attention is given to two new chapters on wavelength tunable DFB laser diodes and bistable and unstable DFB laser diodes. Among many other updates throughout the reference, semi-conductor and electromagnetic professionals are also provided two new appendices. This book fully covers the underlying theory, commercial applications, necessary design criteria, and future direction of this technology.
Download or read book Diode Lasers and Photonic Integrated Circuits written by Larry A. Coldren and published by John Wiley & Sons. This book was released on 2012-03-02 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diode Lasers and Photonic Integrated Circuits, Second Edition provides a comprehensive treatment of optical communication technology, its principles and theory, treating students as well as experienced engineers to an in-depth exploration of this field. Diode lasers are still of significant importance in the areas of optical communication, storage, and sensing. Using the the same well received theoretical foundations of the first edition, the Second Edition now introduces timely updates in the technology and in focus of the book. After 15 years of development in the field, this book will offer brand new and updated material on GaN-based and quantum-dot lasers, photonic IC technology, detectors, modulators and SOAs, DVDs and storage, eye diagrams and BER concepts, and DFB lasers. Appendices will also be expanded to include quantum-dot issues and more on the relation between spontaneous emission and gain.
Download or read book Semiconductor Disk Lasers written by Oleg G. Okhotnikov and published by John Wiley & Sons. This book was released on 2010-03-30 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely publication presents a review of the most recent developments in the field of Semiconductor Disk Lasers. Covering a wide range of key topics, such as operating principles, thermal management, nonlinear frequency conversion, semiconductor materials, short pulse generation, electrical pumping, and laser applications, the book provides readers with a comprehensive account of the fundamentals and latest advances in this rich and diverse field. In so doing, it brings together contributions from world experts at major collaborative research centers in Europe and the USA. Each chapter includes a tutorial style introduction to the selected topic suitable for postgraduate students and scientists with a basic background in optics - making it of interest to a wide range of scientists, researchers, engineers and physicists working and interested in this rapidly developing field. It will also serve as additional reading for students in the field.
Download or read book Optical Microresonators written by John Heebner and published by Springer Science & Business Media. This book was released on 2008 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Micro-Resonators are an exciting new field of research that has gained prominence in the past few years due to the emergence of new fabrication technologies. This book is the first detailed text on the theory, fabrication, and applications of optical micro-resonators, and will be found useful by both graduate students and researchers in the field.
