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Broad-Area Laser Bars for 1 kW-Emission

Printausgabe
EUR 39,50

E-Book
EUR 27,90

Broad-Area Laser Bars for 1 kW-Emission (Band 70)

Demonstrating increased efficiency and narrowed far field

Matthias M. Karow (Autor)

Vorschau

Leseprobe, PDF (790 KB)
Inhaltsverzeichnis, PDF (26 KB)

ISBN-13 (Printausgabe) 9783736976269
ISBN-13 (E-Book) 9783736966260
Sprache Englisch
Seitenanzahl 142
Umschlagkaschierung matt
Auflage 1.
Buchreihe Innovationen mit Mikrowellen und Licht. Forschungsberichte aus dem Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik
Band 70
Erscheinungsort Göttingen
Promotionsort Berlin
Erscheinungsdatum 27.06.2022
Allgemeine Einordnung Dissertation
Fachbereiche Elektrotechnik
Schlagwörter diode laser, high power, high brightness, narrow far field, high efficiency, kW-class, laser bar, material processing, laser pumping, solid-state laser, thin-disk laser, Yb:YAG laser, near-infrared, thermal engineering, thermal waveguide, thermal lens, bar smile, lateral structure, resonator length, industrial laser, broad-area laser, EDAS, beam quality, vertical structure, thermal transient, cross heating, bar edge, sub-structure, deep implantation, chip strain, chip stress, strain-induced waveguide, strain-induced birefringence, strain-induced dichroism, chip mounting, chip soldering, characteristic thermal length, high fill factor, beam quality test station, thermal impedance, thermal resistance, index-guiding trench, emitter resolved, laser array, Diodenlaser, Hochleistung, hochbrillant, schmales Fernfeld, hocheffizient, kW-Klasse, Laserbarren, Materialbearbeitung, Laserpumpen, Festkörper-Laser, Dünnscheiben-Laser, Yb:YAG-Laser, nah-infrarot, thermisches Designen, thermischer Wellenleiter, thermische Linse, Barren-Smile, laterale Belegung, Resonatorlänge, industrieller Laser, Breitstreifen-Laser, EDAS, Strahlgüte, Vertikalstruktur, thermische Transiente, Gegen-Erwärmung, Barren-Kante, Substruktur, Tiefe Implantierung, Chip-Dehnung, Chip-Verspannung, Verspannungs-induzierter Wellenleiter, Verspannungs-induzierte Doppelbrechung, Verspannungs-induzierter Dichroismus, Chip-Aufbau, Chip-Lötung, characteristische thermische Länge, hoher Füllfaktor, Strahlgüte-Messplatz, thermische Impedanz, thermischer Widerstand, Indexleiter-Graben, Emitter-aufgelöst, Laser-Array
URL zu externer Homepage https://www.fbh-berlin.de/publikationen/dissertationen
Beschreibung

Industrial 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.