Development of high power Cw Yb-Doped fiber laser system
Author
Özkan, Elif Gül
Advisor
Ortaç, Bülend
Date
2015-01Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
124
views
views
121
downloads
downloads
Abstract
High-average-power fiber lasers are interesting for many applications, including
scientific instrumentation, industrial material processing, imaging, medical and
military technologies. Fiber concept has well established them as a very
attractive beam delivery system and gain medium for laser applications. Rareearth-
doped fibers are one of the most promising solid-state laser concepts for
efficient diode-pumped high power continuous wave laser systems. In fiber laser
systems, the new generation fiber optical cables are used. Fiber laser systems are
preferred due to the ease of usage in the field, high beam quality, low cost and
low thermo-optic problems. Fiber laser system has an active medium where the
light is amplified all along the fiber. The long active medium leads to reduced
heat problems, high absorption rate of the light, high quality beam and less need
for optimization of the cavity. We designed and developed a high power fiber
laser system for metal processing. Material drilling and cutting, which are
significant processes in industry, are performed with the powerful fiber laser
systems. The main purpose of this thesis is to develop a laser system which
enables fast and accurate cutting process with impressive properties such as
compactness, low maintenance problems and so on. The fiber laser resonator
was first numerically studied by using software and then various laser
parameters and laser architectures were designed. In order to perform the
numerical results, we designed a compact high power all-fiber laser cavity. In
real world applications, the use of free space components to constitute the cavity leads to environmental instabilities and power loss, which results in a decrease
of the fiber laser efficiency. One of the most important advantages of all fiber
laser system is to handle environmental factors such as humidity, vibrations. To
achieve high power level from the fiber laser systems, it is significant to use
powerful pumping systems (high power diode lasers), passive laser cavity
components (combiner, FBG) and also double-clad active fiber that operate at
high power level. In this study, we used new generation laser cavity
components. The pump sources have been analyzed in terms of power and
wavelength stabilities. Also, experiments have been performed to keep pump
sources at optimum temperature to obtain accurate wavelength to excite
ytterbium atoms located in the active media. In order to constitute high power
laser system, we integrated all fiber optic components for efficient operation.
The laser has stable continuous wave regime in temporal domain due to the
cavity design. The output power of the system is about 548 W. The M2 value of
the system is less than < 1.7. The operation wavelength of the fiber laser was
stabilized with FBG at 1.08 μm. We also demonstrate the capability of our fiber
laser system for material processing. We successfully drilled and cut 1.7 mm
thickness steel target with lower output power of fiber laser (100 W).
Keywords
FibersLasers
High-power laser systems
Powerful fiber laser components
Material processing with laser
Permalink
http://hdl.handle.net/11693/29032Related items
Showing items related by title, author, creator and subject.
-
Modeling and cross coupling controller development for a 6DOF laser micro-machining system
Kerimoğlu, Serhat; Çakmakçı, Melih (IEEE, 2017)In recent years, studies on manufacturing systems have proved the importance of cooperation of positioning systems with laser cutting technology. The performance of the manufacturing system can be improved by utilizing ... -
Texturing of titanium (Ti6Al4V) medical implant surfaces with MHz-repetition-rate femtosecond and picosecond Yb-doped fiber lasers
Erdoǧan, M.; Öktem, B.; Kalaycioǧlu H.; Yavaş, S.; Mukhopadhyay P.K.; Eken, K.; Özgören, K.; Aykaç, Y.; Tazebay, U.H.; Ilday F.O. (Optical Society of American (OSA), 2011)We propose and demonstrate the use of short pulsed fiber lasers in surface texturing using MHz-repetition-rate, microjoule- and sub-microjoule-energy pulses. Texturing of titanium-based (Ti6Al4V) dental implant surfaces ... -
Synthesis of blue-shifted luminescent colloidal GaN nanocrystals through femtosecond pulsed laser ablation in organic solution
Demirel, A.; Öztaş T.; Kurşungöz, C.; Yılmaz, İ.; Ortaç, B. (Springer Netherlands, 2016-05)We demonstrate the synthesis of GaN nanocrystals (NCs) with the sizes of less than the doubled exciton Bohr radius leading quantum confinement effects via a single-step technique. The generation of colloidal GaN nanoparticles ...