Download or read book Broad Area Laser Bars for 1 kW Emission written by Matthias M. Karow and published by Cuvillier Verlag. This book was released on 2022-06-27 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: ndustrial laser systems for material processing applications rely on the availability of highly efficient, high-brightness diode lasers. GaAs-based broad-area laser bars play a vital role in such applications as pump sources for high-beam-quality solid-state lasers and, increasingly, as direct processing tools. This work studies 940 nm-laser bars emitting 1 kW optical power at room temperature, identifying those physical mechanisms that are currently limiting electrical-to-optical conversion efficiency as well as lateral beam quality. In the process, several diagnostic studies on bars with varied lateral-longitudinal design were carried out. The effects of technological measures for performance optimization were analyzed, yielding a new benchmark in efficiency and lateral divergence. The studies into altered resonator lengths of 4 and 6 mm as well as fill factors between 69 and 87 % successfully reduce both the voltage dropping across the device and power saturation at high currents, enabling 66 % efficiency at the operation point. Concrete measures how to reach efficiencies ≥70 % are presented thereafter, showing that doubling the efficiency value of the first 1 kW-demonstration in 2007 – amounting to 35 % – is in near reach. Investigation of the beam quality bases on a herein proposed and realized concept, in which the far field is resolved for each individual bar emitter. In this way, it is possible to determine how far-field profiles vary along the bar width and how much these variations affect the overall bar far-field. Further, such effects specific to bar structures can be separated into non-thermal and thermal influences. The effect of mechanical chip deformation (bar smile) as well as neighboring-emitter interaction has been investigated for the first time in active kW-class devices, yielding a lateral divergence as low as 8.8° at the operation point.
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 Transceiver Technologies for Millimeter Wave Beam Steering Applications Band 71 written by Yi-Fan Tsao and published by Cuvillier Verlag. This book was released on 2022-11-08 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past years, wireless communication systems have been rapidly advancing to meet the high data-rate requirements of various emerging applications. However, the existing transceivers have typically been demonstrated using CMOS-compatible technologies that deliver a relatively low equivalent isotropic radiated power in a small unit cell. Moreover, the particular device characteristics are limiting the linear region for operation. Therefore, the main focus of this dissertation is to present and discuss new design methods for transceivers to solve these issues. To reduce the complexity of the transceiver module for further phased-array scaling, a low-noise power amplifier design approach is designed using a 0.15-μm GaN-on-SiC high-electron mobility transistor technology (HEMT). Utilizing a traded off interstage matching topology between loss and bandwidth, the conversion loss induced by the matching network could be effectively reduced. A stacked-FET configuration was adopted to enhance the power handling of the RF switch. Further improvement on the isolation bandwidth was investigated using theoretical analysis on the intrinsic effect of the passive HEMTs. With the successful implementation of the RF front-end circuits, transceiver modules were integrated on Rogers RO3010 substrate. The planar dual exponentially tapered slot antenna phased-array system showed a compact size with simple biasing network compared to the conventional transceiver approach. The presented T/R module was characterized with an over-the-air test at a distance of 1 m, overcoming the free space path loss of 64 dB. It also shows a high flexibility for further integration with a larger number of array systems, which is very promising for future 5G communication systems.
Download or read book Lasers written by Hans Joachim Eichler and published by Springer. This book was released on 2018-11-19 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of laser sources and their applications in various fields of science, industry, and technology. After an introduction to the basics of laser physics, different laser types and materials for lasers are summarized in the context of a historical survey, outlining the evolution of the laser over the past five decades. This includes, amongst other aspects, gas lasers, excimer lasers, the wide range of solid-state and semiconductor lasers, and femtosecond and other pulsed lasers where particular attention is paid to high-power sources. Subsequent chapters address related topics such as laser modulation and nonlinear frequency conversion. In closing, the enormous importance of the laser is demonstrated by highlighting its current applications in everyday life and its potential for future developments. Typical applications in advanced material processing, medicine and biophotonics as well as plasma and X-ray generation for nanoscale lithography are discussed. The book provides broad and topical coverage of laser photonics and opto-electronics, focusing on significant findings and recent advances rather than in-depth theoretical studies. Thus, it is intended not only for university students and engineers, but also for scientists and professionals applying lasers in biomedicine, material processing and everyday consumer products. Further, it represents essential reading for engineers using or developing high-power lasers for scientific or industrial applications.
Download or read book Military Laser Technology for Defense written by Alastair D. McAulay and published by John Wiley & Sons. This book was released on 2011-04-20 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in ultra-high-power lasers, including the free-electron laser, and impressive airborne demonstrations of laser weapons systems, such as the airborne laser, have shown the enormous potential of laser technology to revolutionize 21st century warfare. Military Laser Technology for Defense, includes only unclassified or declassified information. The book focuses on military applications that involve propagation of light through the atmosphere and provides basic relevant background technology. It describes high-power lasers and masers, including the free-electron laser. Further, Military Laser Technology for Defense addresses how laser technology can effectively mitigate six of the most pressing military threats of the 21st century: attack by missiles, terrorists, chemical and biological weapons, as well as difficulty in imaging in bad weather and threats from directed beam weapons and future nuclear weapons. The author believes that laser technology will revolutionize warfare in the 21st century.
Download or read book Atti della Fondazione Giorgio Ronchi written by Fondazione Giorgio Ronchi and published by Lucia Ronchi. This book was released on with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Fiber Lasers and Fiber Amplifiers written by Vartan V. Ter-Mikirtychev and published by Springer Nature. This book was released on 2019-12-30 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the fundamental aspects of fiber lasers and fiber amplifiers, and includes a wide range of material from laser physics fundamentals to state-of-the-art topics in this rapidly growing field of quantum electronics. This expanded and updated new edition includes substantial new material on nonlinear frequency conversion and Raman fiber lasers and amplifiers, as well as an expanded list of references inclusive of the recent literature in the field. Emphasis is placed on the nonlinear processes taking place in fiber lasers and amplifiers, their similarities, differences to, and their advantages over other solid-state lasers. The reader will learn the basic principles of solid-state physics and optical spectroscopy of laser active centers in fibers, the main operational laser regimes, and will receive practical recommendations and suggestions on fiber laser research, laser applications, and laser product development. The book will be useful for students, researchers, and professional physicists and engineers who work with lasers in the optical and telecommunications field, as well as those in the chemical and biological industries.
Download or read book Narrow Gap Semiconductors Proceedings Of The Eighth International Conference written by Sue-chu Shen and published by World Scientific. This book was released on 1998-04-09 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents:Materials and Related Physics: Magnetic Field and Dimensionality Induced Population Effects in HgSe and HgSe:Fe (O Portugall et al)Growth and in Situ Scanning Tunneling Microscopy Studies of IV–VI Semiconductors (Abstract) (G Springholz)Detectors and Arrays: China's Satellite Project for Earth Observation and Infrared Detection (D-B Kuang)Recent Progress in Quantum Well Infrared Photodetectors and Focal Plane Arrays for LWIR Imaging Applications (S S Li)Infrared Lasers: Mid-Infrared Resonant-Cavity-Based Devices: Of Detectors and Emitters (J Bleuse et al)W Lasers for the Mid-IR (J R Meyer et al)Devices and Related Physics: Optoelectronic Devices from Indium Aluminium Antimonide and Mercury Cadmium Telluride (T Ashley)Three-Terminal Superconductor–Semiconductor Devices (H Takayanagi & T Akazaki)Physics: Coherent Anti-Stokes Raman Scattering in Diluted Magnetic IV–VI Epilayers and Superlattices (H Pascher et al)High Field Cyclotron Resonance in GaSb and Effective Mass at the Γ and L-Points (H Arimoto et al)Quantum Dots: Growth and Characterization of InAs Quantum Dots (N N Ledentsov)Self-Assembled InAs Quantum Boxes: Growth, Intrinsic Properties, Potential Applications (Abstract) (J M Gérard)and other papers Readership: Researchers in the field of semiconductors.
Download or read book Springer Handbook of Semiconductor Devices written by Massimo Rudan and published by Springer Nature. This book was released on 2022-11-10 with total page 1680 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Springer Handbook comprehensively covers the topic of semiconductor devices, embracing all aspects from theoretical background to fabrication, modeling, and applications. Nearly 100 leading scientists from industry and academia were selected to write the handbook's chapters, which were conceived for professionals and practitioners, material scientists, physicists and electrical engineers working at universities, industrial R&D, and manufacturers. Starting from the description of the relevant technological aspects and fabrication steps, the handbook proceeds with a section fully devoted to the main conventional semiconductor devices like, e.g., bipolar transistors and MOS capacitors and transistors, used in the production of the standard integrated circuits, and the corresponding physical models. In the subsequent chapters, the scaling issues of the semiconductor-device technology are addressed, followed by the description of novel concept-based semiconductor devices. The last section illustrates the numerical simulation methods ranging from the fabrication processes to the device performances. Each chapter is self-contained, and refers to related topics treated in other chapters when necessary, so that the reader interested in a specific subject can easily identify a personal reading path through the vast contents of the handbook.
Download or read book Handbook of Solid State Lasers written by Peter Cheo and published by CRC Press. This book was released on 1988-11-29 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides information on both state-of-the-art technology and fundamental principles of fully developed solid-state lasers, emphasizing their operational characteristics and physical properties. Six contributions discuss theories and techniques of III-V semiconductor diode lasers, describe various ty
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 Handbook of Laser Technology and Applications written by Chunlei Guo and published by CRC Press. This book was released on 2021-06-23 with total page 711 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive handbook gives a fully updated guide to lasers and laser systems, including the complete range of their technical applications. The first volume outlines the fundamental components of lasers, their properties and working principles. The second volume gives exhaustive coverage of all major categories of lasers, from solid-state and semiconductor diode to fiber, waveguide, gas, chemical, and dye lasers. The third volume covers modern applications in engineering and technology, including all new and updated case studies spanning telecommunications and data storage to medicine, optical measurement, defense and security, nanomaterials processing and characterization.
Download or read book Structural Connections for Lightweight Metallic Structures written by Pedro M.G.P. Moreira and published by Springer Science & Business Media. This book was released on 2012-02-03 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing concern with fuel consumption leads to widespread interest in lightweight structures for transportation vehicles. Several competing technologies are available for the structural connections of these structures, namely welding, mechanical fastening / riveting, and adhesive technologies. Arranged in a single volume, this work is to presents state-of-the-art discussions of those aspects and processes presenting greater novelty whilst simultaneously keeping wide applicability potential and interest. The topics chosen have the common feature of being of currently applied in lightweight structures, and one of the characteristics of this work is bringing together relevant state-of-the-art information usually presented in separate publications specializing in a single technology. The book provides discussions and examples of concrete applications, so that it appeals to researchers and designers and engineers involved in the design and fabrication of lightweight structures.
Download or read book Two step MOVPE in situ etching and buried implantation applications to the realization of GaAs laser diodes written by Pietro della Casa and published by Cuvillier Verlag. This book was released on 2021-03-25 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work is about two-step epitaxial growth using metalorganic vapor-phase epitaxy (MOVPE) for the realization of edge-emitting near-infrared laser diodes. The fabricated gallium arsenide-based devices fall into two categories: high-power lasers (watt range, multimodal) and tunable lasers (milliwatt range, monomodal). Common to both cases is that surface contamination – particularly that due to oxygen – needs to be removed before regrowth. Thus, in-situ etching with carbon tetrabromide (CBr4) is first studied. The experimental results include kinetic data, the effects of different etching conditions as well as substrate characteristics, and the effectiveness in reducing surface contamination. These investigations pave the way to devices based on 2-step epitaxy combined with in-situ etching. Correspondingly, thermally-tuned SG-DBR lasers operating around 975 nm have been successfully realized, obtaining a tuning range of 21 nm. In addition, the possibility of using electronic tuning in similar devices has been explored. High-power broad-area lasers have also been realized, using two-step epitaxy combined with ex-situ and in-situ etching, to create a buried, shallow “mesa” containing the active zone. This approach allows introducing lateral electrical and optical confinement, and – simultaneously – non-absorbing mirrors at the laser facets. Additionally, a different strategy to create a buried current aperture is presented, which is based on ion implantation followed by epitaxial regrowth. This enables to improve device performance and simultaneously introduce non-absorbing mirrors at the facets with correspondingly increased reliability.
Download or read book IEEE International Semiconductor Laser Conference written by and published by . This book was released on 2004 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In plane Semiconductor Lasers written by and published by . This book was released on 1999 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
