Download or read book High Power GaAs Based Diode Lasers with Novel Lateral Designs for Enhanced Brightness Threshold and Efficiency written by Mohamed Elattar and published by Cuvillier Verlag. This book was released on 2024-07-26 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: GaAs-based 9xx-nm broad-area diode lasers (BALs) offer the highest optical power (Popt) among diode lasers and the highest conversion efficiency (ηE) among all light sources. Therefore, they are widely used in material processing applications (e.g. metal cutting), which additionally require high beam quality (i.e. low beam parameter product BPP), typically limited in BALs along the lateral axis (BPPlat). Enhancing BAL performance is dependent on identifying the thermal and non-thermal limiting mechanisms, and implementing design changes to minimize their effects. In this work, two novel approaches based on lateral structuring are developed, aiming to overcome different limiting mechanisms acting along the lateral axis. First, the enhanced self-aligned lateral structure (eSAS) is based on integrating structured current-blocking layers outside the BAL stripe to centrally confine current and charge carriers, thereby suppressing lateral current spreading and lateral carrier accumulation. Two eSAS variants are optimized using simulation tools, then realized in multiple wafer processes, followed by characterization of mounted BALs. eSAS BALs exhibit state-of-the-art Popt and lateral brightness (Popt/BPPlat), with clear benefits over standard gain-guided BALs in terms of threshold, BPPlat and peak ηE. The second approach is chip-internal thermal path engineering, based on structured epitaxial layers replaced outside the stripe by heat-blocking materials to centrally confine heat flow. This flattens the lateral temperature profile (i.e. reduces thermal lensing) around the active zone, which is associated with enhanced brightness. Finite-element thermal simulations are used to estimate the benefits of this approach, thereby motivating its practical realization in future studies.
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 High Power Diode Lasers written by Roland Diehl and published by Springer Science & Business Media. This book was released on 2003-07-01 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Starting from the basics of semiconductor lasers with emphasis on the generation of high optical output power the reader is introduced in a tutorial way to all key technologies required to fabricate high-power diode-laser sources. Various applications are exemplified.
Download or read book High Power Diode Lasers written by Friedrich Bachmann and published by Springer. This book was released on 2007-05-26 with total page 553 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes a five year research project, as well as subsequent results regarding high power diode laser systems and their application in materials processing. The text explores the entire chain of technology, from the semiconductor technology, through cooling mounting and assembly, beam shaping and system technology, to applications in the processing of such materials as metals and polymers. Includes theoretical models, a range of important parameters and practical tips.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
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 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 Integrated Optics and Optical Switching written by IGIC, Inc. Staff and published by Information Gatekeepers Inc. This book was released on 1994 with total page 1038 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Summaries of Papers Presented at the Conference on Lasers and Electro Optics written by and published by . This book was released on 1998 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Optics written by Boris Lembrikov and published by BoD – Books on Demand. This book was released on 2019-02-06 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonlinear optics is a rapidly developing field of modern physics. Nonlinear optical phenomena such as self-focusing, self-phase modulation, soliton formation and propagation, higher harmonic generation, different types of stimulated light scattering, and four-wave mixing have attracted interest from the fundamental point of view of the investigation of light/matter interaction, and as a basis for applications in contemporary optical communications and optical signal processing. Nonlinear Optics - Novel Results in Theory and Applications contains novel results concerning the mathematical methods of nonlinear optical phenomena analysis, soliton formation and propagation in optical fibers, and peculiarities of nonlinear optical phenomena in micro- and nanostructures. The book may be interesting for researchers and engineers interested in nonlinear optics, lasers, and optical communications.
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2008 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theses on any subject submitted by the academic libraries in the UK and Ireland.
Download or read book Applied Nanophotonics written by Sergey V. Gaponenko and published by Cambridge University Press. This book was released on 2019 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: An accessible yet rigorous introduction to nanophotonics, covering basic principles, technology, and applications in lighting, lasers, and photovoltaics. Providing a wealth of information on materials and devices, and over 150 color figures, it is the 'go-to' guide for students in electrical engineering taking courses in nanophotonics.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of Solid State Lighting Phase Two written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2017-05-11 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: The standard incandescent light bulb, which still works mainly as Thomas Edison invented it, converts more than 90% of the consumed electricity into heat. Given the availability of newer lighting technologies that convert a greater percentage of electricity into useful light, there is potential to decrease the amount of energy used for lighting in both commercial and residential applications. Although technologies such as compact fluorescent lamps (CFLs) have emerged in the past few decades and will help achieve the goal of increased energy efficiency, solid-state lighting (SSL) stands to play a large role in dramatically decreasing U.S. energy consumption for lighting. Since the publication of the 2013 National Research Council report Assessment of Advanced Solid-State Lighting, the penetration of SSL has increased dramatically, with a resulting savings in energy and costs that were foreshadowed by that study. What was not anticipated then is the dramatic dislocation and restructuring of the SSL marketplace, as cost reductions for light-emitting diode (LED) components reduced profitability for LED manufacturers. At the same time, there has been the emergence of new applications for SSL, which have the potential to create new markets and commercial opportunities for the SSL industry. Assessment of Solid-State Lighting, Phase Two discusses these aspects of changeâ€"highlighting the progress of commercialization and acceptance of SSL and reviewing the technical advances and challenges in achieving higher efficacy for LEDs and organic light-emitting diodes. This report will also discuss the recent trends in SSL manufacturing and opportunities for new applications and describe the role played by the Department of Energy (DOE) Lighting Program in the development of SSL.
