Broad-Area Laser Bars for 1 kW-Emission

Broad-Area Laser Bars for 1 kW-Emission PDF Author: Matthias M. Karow
Publisher: Cuvillier Verlag
ISBN: 3736966261
Category : Technology & Engineering
Languages : en
Pages : 143

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Book Description
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.

Broad-Area Laser Bars for 1 kW-Emission

Broad-Area Laser Bars for 1 kW-Emission PDF Author: Matthias M. Karow
Publisher: Cuvillier Verlag
ISBN: 3736966261
Category : Technology & Engineering
Languages : en
Pages : 143

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Book Description
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.

High-Power Diode Lasers

High-Power Diode Lasers PDF Author: Roland Diehl
Publisher: Springer Science & Business Media
ISBN: 3540478523
Category : Science
Languages : en
Pages : 420

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Book Description
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.

Narrow Gap Semiconductors - Proceedings Of The Eighth International Conference

Narrow Gap Semiconductors - Proceedings Of The Eighth International Conference PDF Author: Sue-chu Shen
Publisher: World Scientific
ISBN: 9814545325
Category :
Languages : en
Pages : 494

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Book Description
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.

Fundamentals of Fiber Lasers and Fiber Amplifiers

Fundamentals of Fiber Lasers and Fiber Amplifiers PDF Author: Vartan V. Ter-Mikirtychev
Publisher: Springer Nature
ISBN: 3030338908
Category : Science
Languages : en
Pages : 345

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Book Description
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.

Lasers

Lasers PDF Author: Hans Joachim Eichler
Publisher: Springer
ISBN: 3319998951
Category : Science
Languages : en
Pages : 507

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Book Description
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.

Military Laser Technology for Defense

Military Laser Technology for Defense PDF Author: Alastair D. McAulay
Publisher: John Wiley & Sons
ISBN: 1118019547
Category : Technology & Engineering
Languages : en
Pages : 336

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Book Description
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.

Optical Fiber Telecommunications VA

Optical Fiber Telecommunications VA PDF Author: Tingye Li
Publisher: Elsevier
ISBN: 0080569617
Category : Technology & Engineering
Languages : en
Pages : 945

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Book Description
Optical Fiber Telecommunications V (A&B) is the fifth in a series that has chronicled the progress in the research and development of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition not only brings a fresh look to many essential topics but also focuses on network management and services. Using high bandwidth in a cost-effective manner for the development of customer applications is a central theme. This book is ideal for R&D engineers and managers, optical systems implementers, university researchers and students, network operators, and the investment community. Volume (A) is devoted to components and subsystems, including: semiconductor lasers, modulators, photodetectors, integrated photonic circuits, photonic crystals, specialty fibers, polarization-mode dispersion, electronic signal processing, MEMS, nonlinear optical signal processing, and quantum information technologies. Volume (B) is devoted to systems and networks, including: advanced modulation formats, coherent systems, time-multiplexed systems, performance monitoring, reconfigurable add-drop multiplexers, Ethernet technologies, broadband access and services, metro networks, long-haul transmission, optical switching, microwave photonics, computer interconnections, and simulation tools. Biographical Sketches Ivan Kaminow retired from Bell Labs in 1996 after a 42-year career. He conducted seminal studies on electrooptic modulators and materials, Raman scattering in ferroelectrics, integrated optics, semiconductor lasers (DBR , ridge-waveguide InGaAsP and multi-frequency), birefringent optical fibers, and WDM networks. Later, he led research on WDM components (EDFAs, AWGs and fiber Fabry-Perot Filters), and on WDM local and wide area networks. He is a member of the National Academy of Engineering and a recipient of the IEEE/OSA John Tyndall, OSA Charles Townes and IEEE/LEOS Quantum Electronics Awards. Since 2004, he has been Adjunct Professor of Electrical Engineering at the University of California, Berkeley. Tingye Li retired from AT&T in 1998 after a 41-year career at Bell Labs and AT&T Labs. His seminal work on laser resonator modes is considered a classic. Since the late 1960s, He and his groups have conducted pioneering studies on lightwave technologies and systems. He led the work on amplified WDM transmission systems and championed their deployment for upgrading network capacity. He is a member of the National Academy of Engineering and a foreign member of the Chinese Academy of Engineering. He is a recipient of the IEEE David Sarnoff Award, IEEE/OSA John Tyndall Award, OSA Ives Medal/Quinn Endowment, AT&T Science and Technology Medal, and IEEE Photonics Award. Alan Willner has worked at AT&T Bell Labs and Bellcore, and he is Professor of Electrical Engineering at the University of Southern California. He received the NSF Presidential Faculty Fellows Award from the White House, Packard Foundation Fellowship, NSF National Young Investigator Award, Fulbright Foundation Senior Scholar, IEEE LEOS Distinguished Lecturer, and USC University-Wide Award for Excellence in Teaching. He is a Fellow of IEEE and OSA, and he has been President of the IEEE LEOS, Editor-in-Chief of the IEEE/OSA J. of Lightwave Technology, Editor-in-Chief of Optics Letters, Co-Chair of the OSA Science & Engineering Council, and General Co-Chair of the Conference on Lasers and Electro-Optics.

Optical Fiber Telecommunications VA

Optical Fiber Telecommunications VA PDF Author: Ivan Kaminow
Publisher: Academic Press
ISBN: 0080565018
Category : Technology & Engineering
Languages : en
Pages : 945

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Book Description
Optical Fiber Telecommunications V (A&B) is the fifth in a series that has chronicled the progress in the research and development of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition not only brings a fresh look to many essential topics but also focuses on network management and services. Using high bandwidth in a cost-effective manner for the development of customer applications is a central theme. This book is ideal for R&D engineers and managers, optical systems implementers, university researchers and students, network operators, and the investment community. Volume (A) is devoted to components and subsystems, including: semiconductor lasers, modulators, photodetectors, integrated photonic circuits, photonic crystals, specialty fibers, polarization-mode dispersion, electronic signal processing, MEMS, nonlinear optical signal processing, and quantum information technologies. Volume (B) is devoted to systems and networks, including: advanced modulation formats, coherent systems, time-multiplexed systems, performance monitoring, reconfigurable add-drop multiplexers, Ethernet technologies, broadband access and services, metro networks, long-haul transmission, optical switching, microwave photonics, computer interconnections, and simulation tools. Biographical Sketches Ivan Kaminow retired from Bell Labs in 1996 after a 42-year career. He conducted seminal studies on electrooptic modulators and materials, Raman scattering in ferroelectrics, integrated optics, semiconductor lasers (DBR , ridge-waveguide InGaAsP and multi-frequency), birefringent optical fibers, and WDM networks. Later, he led research on WDM components (EDFAs, AWGs and fiber Fabry-Perot Filters), and on WDM local and wide area networks. He is a member of the National Academy of Engineering and a recipient of the IEEE/OSA John Tyndall, OSA Charles Townes and IEEE/LEOS Quantum Electronics Awards. Since 2004, he has been Adjunct Professor of Electrical Engineering at the University of California, Berkeley. Tingye Li retired from AT&T in 1998 after a 41-year career at Bell Labs and AT&T Labs. His seminal work on laser resonator modes is considered a classic. Since the late 1960s, He and his groups have conducted pioneering studies on lightwave technologies and systems. He led the work on amplified WDM transmission systems and championed their deployment for upgrading network capacity. He is a member of the National Academy of Engineering and a foreign member of the Chinese Academy of Engineering. He is a recipient of the IEEE David Sarnoff Award, IEEE/OSA John Tyndall Award, OSA Ives Medal/Quinn Endowment, AT&T Science and Technology Medal, and IEEE Photonics Award. Alan Willner has worked at AT&T Bell Labs and Bellcore, and he is Professor of Electrical Engineering at the University of Southern California. He received the NSF Presidential Faculty Fellows Award from the White House, Packard Foundation Fellowship, NSF National Young Investigator Award, Fulbright Foundation Senior Scholar, IEEE LEOS Distinguished Lecturer, and USC University-Wide Award for Excellence in Teaching. He is a Fellow of IEEE and OSA, and he has been President of the IEEE LEOS, Editor-in-Chief of the IEEE/OSA J. of Lightwave Technology, Editor-in-Chief of Optics Letters, Co-Chair of the OSA Science & Engineering Council, and General Co-Chair of the Conference on Lasers and Electro-Optics. For nearly three decades, the OFT series has served as the comprehensive primary resource covering progress in the science and technology of optical fiber telecom. It has been essential for the bookshelves of scientists and engineers active in the field. OFT V provides updates on considerable progress in established disciplines, as well as introductions to new topics. [OFT V]... generates a value that is even higher than that of the sum of its chapters.

State-of-the-Art Program on Compound Semiconductors XL : (SOTAPOCS XL) and Narrow Bandgap Optoelectronic Materials and Devices II

State-of-the-Art Program on Compound Semiconductors XL : (SOTAPOCS XL) and Narrow Bandgap Optoelectronic Materials and Devices II PDF Author: D. N. Buckley
Publisher: The Electrochemical Society
ISBN: 9781566774079
Category : Technology & Engineering
Languages : en
Pages : 302

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Book Description


Two-step MOVPE, in-situ etching and buried implantation: applications to the realization of GaAs laser diodes

Two-step MOVPE, in-situ etching and buried implantation: applications to the realization of GaAs laser diodes PDF Author: Pietro della Casa
Publisher: Cuvillier Verlag
ISBN: 3736963971
Category : Science
Languages : en
Pages : 250

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Book Description
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.