Dr. Sonja Unger Profile

Dr. Sonja Unger

at Leibniz-Institut für Photonische Technologien eV

SPIE Involvement:

Author

Publications (41)

Proceedings Article | 9 March 2024 Presentation

Presentation

Tuning specialty co-doped optical silica fibers for sensing applications

Tobias Habisreuther, Sonja Unger, Anett Reichert, Claudia Aichele, Florian Lindner, Stefan Kuhn, Adrian Lorenz, Jörg Bierlich, Anka Schuchow, Tina Eschrich, Kay Schaarschmidt, Martin Lorenz, Katrin Wondraczek

Proceedings Volume PC12882, PC128820E (2024) https://doi.org/10.1117/12.3002626

KEYWORDS: Optical fibers, Optical properties, Codoping, Materials properties, Dopants, Structured optical fibers, Silica, Refractive index, Optical design, Germanium

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Proceedings Article | 8 March 2024 Presentation + Paper

Presentation + Paper

Multi-core optical fibers with adapted functionalities for imaging and sensing applications

S. Unger, A. Reichert, C. Aichele, F. Lindner, S. Kuhn, A. Lorenz, J. Bierlich, A. Schwuchow, T. Eschrich, K. Schaarschmidt, M. Lorenz, K. Wondraczek, T. Habisreuther

Proceedings Volume 12882, 128820F (2024) https://doi.org/10.1117/12.3002680

KEYWORDS: Refractive index, Germanium, Aluminum, Acoustics, Silica, Optical fibers, Dopants, Doping, Fiber Bragg gratings, Diffusion

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Proceedings Article | 8 March 2023 Presentation + Paper

Presentation + Paper

Crystal-derived double-clad fibers for high gain and high efficiency Tm fiber lasers

Martin Leich, Robert Müller, Sonja Unger, Anka Schwuchow, Jan Dellith, Jens Kobelke, Adrian Lorenz, Matthias Jäger

Proceedings Volume 12400, 1240012 (2023) https://doi.org/10.1117/12.2650340

KEYWORDS: Fiber lasers, Crystals, Thulium, Laser crystals, Doping, Aluminum, Silica

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Proceedings Article | 16 March 2015 Paper

Paper

The REPUSIL process and the capability of fluorine doping for the adjustment of optical and thermochemical properties in silica materials

K. Schuster, St. Grimm, A. Kalide, Jan Dellith, M. Leich, A. Schwuchow, S. Unger, A. Langner, G. Schötz, H. Bartelt

Proceedings Volume 9359, 935914 (2015) https://doi.org/10.1117/12.2077395

KEYWORDS: Fluorine, Silica, Aluminum, Glasses, Refractive index, Doping, Ytterbium, Cladding, Thermography, Ions

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Proceedings Article | 20 February 2015 Paper

Paper

Demonstration of >5kW emissions with good beam quality from two different 7:1 all-glass fiber coupler-types

M. Plötner, T. Eschrich, O. de Vries, J. Kobelke, S. Unger, M. Jäger, T. Schreiber, H. Bartelt, R. Eberhardt, A. Tünnermann

Proceedings Volume 9346, 93460W (2015) https://doi.org/10.1117/12.2077580

KEYWORDS: Fiber lasers, Fiber couplers, Multimode fibers, Cladding, Fiber optics, Single mode fibers, Step index fibers, Capillaries, Silicon, Precision optics

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SPIE Journal Paper | 3 June 2014 Open Access

Open Access

Length distributed measurement of temperature effects in Yb-doped fibers during pumping

Martin Leich, Julia Fiebrandt, Anka Schwuchow, Sylvia Jetschke, Sonja Unger, Matthias Jäger, Manfred Rothhardt, Hartmut Bartelt

OE, Vol. 53, Issue 06, 066101, (June 2014) https://doi.org/10.1117/12.10.1117/1.OE.53.6.066101

KEYWORDS: Optical fibers, Fiber Bragg gratings, Temperature metrology, Ytterbium, Absorption, Ultraviolet radiation, Cerium, Fiber lasers, Optical pumping, Hydrogen

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Proceedings Article | 2 June 2014 Paper

Paper

In-line Mach-Zehnder interferometer based on a dissimilar-doping dual-core fiber for high sensitivity strain and temperature sensing

H, Martins, J. Bierlich, K. Wondraczek, S. Unger, J. Kobelke, K. Schuster, M. Marques, M. Gonzalez-Herraez, O. Frazão

Proceedings Volume 9157, 91572C (2014) https://doi.org/10.1117/12.2059555

KEYWORDS: Interferometers, Temperature metrology, Mach-Zehnder interferometers, Germanium, Refractive index, Sensors, Phosphorus, Single mode fibers, Fiber optics sensors, Temperature sensors

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Proceedings Article | 7 March 2014 Paper

Paper

Optical properties of Yb-doped fibers prepared by gas phase doping

F. Lindner, C. Aichele, A. Schwuchwo, M. Leich, A. Scheffel, S. Unger

Proceedings Volume 8982, 89820R (2014) https://doi.org/10.1117/12.2036928

KEYWORDS: Aluminum, Ytterbium, Doping, Optical fibers, Silica, Refractive index, Absorption, Fiber lasers, Oxygen, Deposition processes

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Proceedings Article | 7 March 2014 Paper

Paper

Optimization of laser fibers for high pump light absorption

Jörg Bierlich, Jens Kobelke, Sylvia Jetschke, Stephan Grimm, Sonja Unger, Kay Schuster

Proceedings Volume 8961, 896123 (2014) https://doi.org/10.1117/12.2039231

KEYWORDS: Optical fibers, Fiber lasers, Absorption, Glasses, Signal attenuation, Silica, Refractive index, Refraction, Laser applications, Laser glasses

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Proceedings Article | 7 March 2014 Paper

Paper

Spatially resolved in-core temperature measurement in rare-earth doped fibers during pumping

Julia Fiebrandt, Martin Leich, Sonja Unger, Anka Schwuchow, Matthias Jäger, Manfred Rothhardt, Hartmut Bartelt

Proceedings Volume 8982, 898206 (2014) https://doi.org/10.1117/12.2037663

KEYWORDS: Fiber Bragg gratings, Optical fibers, Temperature metrology, Fiber lasers, Absorption, Fabrication, Cerium, Optical pumping, Fiber amplifiers, Near infrared

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Proceedings Article | 20 February 2014 Paper

Paper

Improvement of optical damage in specialty fiber at 266 nm wavelength

T. Tobisch, H. Ohlmeyer, H. Zimmermann, S. Prein, J. Kirchhof, S. Unger, M. Belz, K.-F. Klein

Proceedings Volume 8938, 89380G (2014) https://doi.org/10.1117/12.2041798

KEYWORDS: Fiber lasers, Pulsed laser operation, Ultraviolet radiation, Nd:YAG lasers, Lamps, Absorption, Silica, Fiber optics, Hydrogen, Laser applications

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Proceedings Article | 11 March 2013 Paper

Paper

Optical properties of cerium-codoped high power laser fibers

S. Unger, A. Schwuchow, S. Jetschke, S. Grimm, A. Scheffel, J. Kirchhof

Proceedings Volume 8621, 862116 (2013) https://doi.org/10.1117/12.2002399

KEYWORDS: Cerium, Optical fibers, Ytterbium, Absorption, Aluminum, Ultraviolet radiation, Luminescence, Doping, Refractive index, Hydrogen

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Proceedings Article | 31 August 2011 Paper

Paper

160W single-mode single-frequency Yb-doped fiber laser with fiber Bragg grating inscribed by UV femtosecond exposure and two beam interference

Martin Becker, Sven Brückner, Eric Lindner, Martin Leich, Manfred Rothhardt, Sonja Unger, Hartmut Bartelt

Proceedings Volume 8007, 80070B (2011) https://doi.org/10.1117/12.904730

KEYWORDS: Fiber Bragg gratings, Fiber lasers, Femtosecond phenomena, Ultraviolet radiation, Interferometry, Modulation, Mirrors, Reflectivity, Refractive index, Reflectors

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Proceedings Article | 11 February 2011 Paper

Paper

Fibers and fiber-optic components for high-power fiber lasers

H. Zimer, M. Kozak, A. Liem, F. Flohrer, F. Doerfel, P. Riedel, S. Linke, R. Horley, F. Ghiringhelli, S. Desmoulins, M. Zervas, J. Kirchhof, S. Unger, S. Jetschke, T. Peschel, T. Schreiber

Proceedings Volume 7914, 791414 (2011) https://doi.org/10.1117/12.879622

KEYWORDS: Fiber lasers, Absorption, Optical fibers, Ytterbium, Phosphorus, Glasses, Refractive index, Aluminum, Cladding, Single mode fibers

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Proceedings Article | 23 September 2010 Paper

Paper

Fiber Bragg grating inscription with UV femtosecond exposure and two beam interference for fiber laser applications

Martin Becker, Sven Brückner, Eric Lindner, Manfred Rothhardt, Sonja Unger, Jens Kobelke, Kay Schuster, Hartmut Bartelt

Proceedings Volume 7750, 775015 (2010) https://doi.org/10.1117/12.871009

KEYWORDS: Fiber Bragg gratings, Fiber lasers, Femtosecond phenomena, Hydrogen, Ultraviolet radiation, Reflection, Germanium, Mirrors, Interferometry, Femtosecond fiber lasers

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Proceedings Article | 18 May 2010 Paper

Paper

Thin-disk-laser-pumped ytterbium-doped fiber laser with an output power in the kW range

A. Popp, A. Voss, Th. Graf, S. Unger, J. Kirchhof, H. Bartelt

Proceedings Volume 7721, 772102 (2010) https://doi.org/10.1117/12.854321

KEYWORDS: Fiber lasers, Cladding, Absorption, Mirrors, Disk lasers, Coating, Optical simulations, Ions, Active optics, Laser sources

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Proceedings Article | 18 May 2010 Paper

Paper

Thermal stress anomaly in rare-earth-doped fiber materials for high-power fiber lasers codoped with aluminum and phosphorus

F. Just, S. Unger, J. Kirchhof, V. Reichel, H. Bartelt

Proceedings Volume 7721, 772106 (2010) https://doi.org/10.1117/12.854193

KEYWORDS: Aluminum, Phosphorus, Refractive index, Doping, Ytterbium, Glasses, Silica, Optical fibers, Cladding, Superposition

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Proceedings Article | 26 February 2010 Paper

Paper

The influence of Yb2+ ions on optical properties and power stability of ytterbium-doped laser fibers

J. Kirchhof, S. Unger, A. Schwuchow, S. Jetschke, V. Reichel, M. Leich, A. Scheffel

Proceedings Volume 7598, 75980B (2010) https://doi.org/10.1117/12.841808

KEYWORDS: Ytterbium, Absorption, Ultraviolet radiation, Aluminum, Optical fibers, Ions, Luminescence, Silica, Glasses, Doping

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Proceedings Article | 17 February 2010 Paper

Paper

Temperature dependence of photodarkening kinetics

M. Leich, S. Jetschke, S. Unger, J. Kirchhof

Proceedings Volume 7580, 758009 (2010) https://doi.org/10.1117/12.845846

KEYWORDS: Color centers, Temperature metrology, Absorption, Annealing, Ytterbium, Thermal modeling, Thermal effects, Glasses, Time metrology, Fiber lasers

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Proceedings Article | 5 August 2009 Paper

Paper

Fiber Bragg grating inscription with DUV femtosecond exposure and two beam interference

Martin Becker, Joachim Bergmann, Sven Brückner, Eric Lindner, Manfred Rothhardt, Kay Schuster, Jens Kobelke, Sonja Unger, Hartmut Bartelt, Luis Fernandes, Paulo V. S. Marques

Proceedings Volume 7386, 73862Y (2009) https://doi.org/10.1117/12.838605

KEYWORDS: Fiber Bragg gratings, Femtosecond phenomena, Interferometers, Silica, Mirrors, Fiber lasers, Germanium, Refractive index, Glasses, Absorption

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Fiber Bragg gratings (FBGs) are today fundamental components in fiber optics. They can be used as sensors, in signal processing, e.g. telecom applications, as wavelength stabilizers in fiber lasers or in dispersion compensators. However, there are applications where the demand for fiber Bragg gratings is not compatible with standard photosensitivity techniques like germanium doping or hydrogen loading. Examples are their use as laser-mirrors in spliceless all fiber fiber-laser solutions or the fiber Bragg grating inscription in suspended core all silica fibers for evanescent field sensing. Fiber Bragg grating inscription with femtosecond-laser exposure is a challenging new method to realize grating structures for waveguides made of materials which do not provide UV-photosensitivity. Especially fs-IR-inscription has been demonstrated for Bragg grating inscription in a variety of material systems such as boron-silica glass, sapphire and pure silica glass. The feasibility of the phase mask FBG inscription technique with DUV femtosecond lasers was also shown, which allows grating inscription even in pure silica microstructured fibers. The phase mask inscription method requires that the fiber will be placed directly behind the phase mask. While the laser beam should be focused onto the fiber to support nonlinear material interaction, this inscription method also leads to phase mask degradations, presumably due to non-bridging oxygen holes (NBOH). Our solution to avoid the mask degradation is to increase the space between fiber and phase mask by using a Talbot-interferometer. Another advantage is the wavelength versatility of this inscription setup. Due to the short temporal coherence length of the femtosecond pulses, the angular alignment variability of the interferometer mirrors is limited and restrictions concerning the wavelength versatility of the interferometer arise. Grating arrays in pure silica suspended core fibers are demonstrated as an example for the versatility of the inscription arrangement.

Proceedings Article | 19 February 2009 Paper

Paper

Characterization of photodarkening processes in Yb doped fibers

S. Jetschke, U. Röpke, S. Unger, J. Kirchhof

Proceedings Volume 7195, 71952B (2009) https://doi.org/10.1117/12.807544

KEYWORDS: Ytterbium, Optical fibers, Color centers, Time metrology, Transmittance, Ions, Cladding, Switching, Manufacturing, Fiber lasers

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Proceedings Article | 19 February 2009 Paper

Paper

Comparison of silica-based materials and fibers in side- and end-pumped fiber lasers

Andreas Langner, Gerhard Schötz, Mario Such, Volker Reichel, Stephan Grimm, Martin Leich, Sonja Unger, Johannes Kirchhof, Björn Wedel, Volker Krause, Georg Rehmann

Proceedings Volume 7195, 71950Q (2009) https://doi.org/10.1117/12.808218

KEYWORDS: Optical fibers, Fiber lasers, Cladding, Silica, Doping, Semiconductor lasers, Signal attenuation, Phosphorus, Laser development, Laser applications

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Proceedings Article | 19 February 2009 Paper

Paper

Yb-doped silica-based laser fibers: correlation of photodarkening kinetics and related optical properties with the glass composition

J. Kirchhof, S. Unger, S. Jetschke, A. Schwuchow, M. Leich, V. Reichel

Proceedings Volume 7195, 71950S (2009) https://doi.org/10.1117/12.808918

KEYWORDS: Ytterbium, Glasses, Absorption, Ions, Luminescence, Optical fibers, Ultraviolet radiation, Aluminum, Optical properties, Oxygen

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Proceedings Article | 7 February 2009 Paper

Paper

Influence of aluminum-phosphorus codoping on optical properties of ytterbium-doped laser fibers

S. Unger, A. Schwuchow, S. Jetschke, V. Reichel, M. Leich, A. Scheffel, J. Kirchhof

Proceedings Volume 7212, 72121B (2009) https://doi.org/10.1117/12.808940

KEYWORDS: Optical fibers, Aluminum, Ytterbium, Absorption, Phosphorus, Refractive index, Luminescence, Fiber lasers, Glasses, Optical properties

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Proceedings Article | 22 February 2008 Paper

Paper

Photodarkening in Yb-doped silica fibers: influence of the atmosphere during preform collapsing

S. Jetschke, S. Unger, A. Schwuchow, M. Leich, V. Reichel, J. Kirchhof

Proceedings Volume 6873, 68731G (2008) https://doi.org/10.1117/12.776638

KEYWORDS: Optical fibers, Ytterbium, Fiber lasers, Ions, Cladding, Oxygen, Luminescence, Glasses, Absorption, Near infrared

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Proceedings Article | 5 February 2008 Paper

Paper

Optical properties of Yb-doped laser fibers in dependence on codopants and preparation conditions

S. Unger, A. Schwuchow, S. Jetschke, V. Reichel, A. Scheffel, J. Kirchhof

Proceedings Volume 6890, 689016 (2008) https://doi.org/10.1117/12.762967

KEYWORDS: Optical fibers, Ytterbium, Absorption, Phosphorus, Luminescence, Aluminum, Ultraviolet radiation, Fiber lasers, Ions, Glasses

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Proceedings Article | 22 February 2007 Paper

Paper

Preparation of large-mode-area laser fibers with microstructured cores

Jens Kobelke, Kay Schuster, Sonja Unger, Volker Reichel, Anka Schwuchow, Klaus Mörl, Johannes Kirchhof, Martin Leich

Proceedings Volume 6453, 64531T (2007) https://doi.org/10.1117/12.698985

KEYWORDS: Optical fibers, Cladding, Ytterbium, Absorption, Signal attenuation, Refractive index, Fiber lasers, Fluorine, Silica, Phosphorus

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Proceedings Article | 20 February 2007 Paper

Paper

Codoped materials for high power fiber lasers: diffusion behaviour and optical properties

Sonja Unger, Anka Schwuchow, Jan Dellith, Johannes Kirchhof

Proceedings Volume 6469, 646913 (2007) https://doi.org/10.1117/12.700161

KEYWORDS: Aluminum, Phosphorus, Glasses, Refractive index, Diffusion, Silica, Aluminium phosphide, Doping, Optical properties, Signal attenuation

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Proceedings Article | 23 September 2005 Paper

Paper

Materials and technologies for microstructured high power laser fibers

J. Kirchhof, S. Unger, J. Kobelke, K. Schuster, K. Mörl, S. Jetschke, A. Schwuchow

Proceedings Volume 5951, 595107 (2005) https://doi.org/10.1117/12.622667

KEYWORDS: Optical fibers, Fiber lasers, Doping, Cladding, Refractive index, Absorption, Ytterbium, Boron, Solids, Aluminum

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SPIE Journal Paper | 1 June 2005 Open Access

Open Access

High-reflectivity draw-tower fiber Bragg gratings—arrays and single gratings of type II

Christoph Chojetzki, Manfred Rothhardt, J. Ommer, Sonja Unger, Kay Schuster, Hans-Rainer Mueller

OE, Vol. 44, Issue 06, 060503, (June 2005) https://doi.org/10.1117/12.10.1117/1.1927517

KEYWORDS: Reflectivity, Fiber Bragg gratings, Excimer lasers, Manufacturing, Sensors, Pulsed laser operation, Interferometers, Single mode fibers, Optical components, Ultraviolet radiation

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Proceedings Article | 22 April 2005 Paper

Paper

Nd:Yb-codoped silica fibers for high power fiber lasers: fluorescence and laser properties

Sylvia Jetschke, Volker Reichel, Klaus Moerl, Sonja Unger, Ulrich Roepke, Hans-Rainer Mueller

Proceedings Volume 5709, (2005) https://doi.org/10.1117/12.593408

KEYWORDS: Neodymium, Ytterbium, Fiber lasers, Ions, Luminescence, Absorption, Energy transfer, Optical fibers, High power fiber lasers, High power lasers

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Proceedings Article | 4 April 2005 Paper

Paper

Dopant interactions in high-power laser fibers

Johannes Kirchhof, Sonja Unger, Anka Schwuchow, Sylvia Jetschke, Bruno Knappe

Proceedings Volume 5723, (2005) https://doi.org/10.1117/12.590021

KEYWORDS: Absorption, Optical fibers, Neodymium, Ytterbium, Aluminum, Refractive index, Luminescence, Silica, Glasses, Germanium

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Proceedings Article | 23 March 2005 Paper

Paper

Fiber-laser power scaling beyond the 1-kilowatt level by Nd:Yb co-doping

Volker Reichel, Klaus Moerl, Sonja Unger, Sylvia Jetschke, Hans-Rainer Mueller, Johannes Kirchhof, Thomas Sandrock, Alexander Harschack, Andreas Liem, Jens Limpert, Holger Zellmer, Andreas Tuennermann

Proceedings Volume 5777, (2005) https://doi.org/10.1117/12.611066

KEYWORDS: Optical fibers, Energy transfer, Semiconductor lasers, Silica, Neodymium, Materials processing, Laser marking, Fiber lasers, Ytterbium, Absorption

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Proceedings Article | 14 June 2004 Paper

Paper

Spatial distribution effects and laser efficiency in Er/Yb-doped fibers

Johannes Kirchhof, Sonja Unger, Anka Schwuchow, Sylvia Jetschke, Bruno Knappe

Proceedings Volume 5350, (2004) https://doi.org/10.1117/12.527958

KEYWORDS: Phosphorus, Diffusion, Aluminum, Luminescence, Ytterbium, Optical fibers, Erbium, Fiber lasers, Doping, Glasses

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Proceedings Article | 7 June 2004 Paper

Paper

Air-clad large-mode-area photonic crystal fibers: power scaling concepts up to the multi-kW range

Andreas Liem, Jens Limpert, Thomas Schreiber, Stefan Nolte, Holger Zellmer, Andreas Tuennermann, Jes Broeng, Guillaume Vienne, Anders Petersson, Christian Jakobsen, Thomas Peschel, Volker Guyenot, Volker Reichel, Sonja Unger

Proceedings Volume 5335, (2004) https://doi.org/10.1117/12.532840

KEYWORDS: Cladding, Fiber lasers, Bridges, Coating, Photonic crystal fibers, Silica, Finite element methods, Continuous wave operation, Absorption, Ytterbium

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Proceedings Article | 3 July 2003 Paper

Paper

Applications of pumped-multiplexed Yb-doped fiber lasers

Volker Reichel, Sonja Unger, Sven Bruckner, Klaus Morl, Hans-Rainer Muller, Johannes Kirchhof, Thomas Sandrock, Alexander Harschack

Proceedings Volume 4974, (2003) https://doi.org/10.1117/12.478266

KEYWORDS: Fiber lasers, Absorption, Ytterbium, Glasses, Semiconductor lasers, Mirrors, Dielectric mirrors, Silicon, Refractive index, Silica

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Proceedings Article | 1 July 2003 Paper

Paper

Fiber lasers: materials, structures and technologies

Johannes Kirchhof, Sonja Unger, Anka Schwuchow

Proceedings Volume 4957, (2003) https://doi.org/10.1117/12.498062

KEYWORDS: Aluminum, Diffusion, Fiber lasers, Glasses, Silica, Ytterbium, Doping, Neodymium, Luminescence, Cladding

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Proceedings Article | 26 March 2002 Paper

Paper

Transmission behavior of silica core: fluorine-doped cladding fibers in the visible and ultraviolet region

Sonja Unger, Johannes Kirchhof, Siegmund Schroeter, Anka Schwuchow, Holger Frost

Proceedings Volume 4616, (2002) https://doi.org/10.1117/12.463809

KEYWORDS: Silica, Doping, Absorption, Oxygen, Optical fibers, Ultraviolet radiation, Germanium, Diffusion, Aluminum, Fluorine

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Proceedings Article | 19 October 2001 Paper

Paper

High-power stability of optical fibers for the visible wavelength region

Johannes Kirchhof, Sonja Unger, Siegmund Schroeter, Anka Schwuchow, Holger Frost, Christhard Deter

Proceedings Volume 4579, (2001) https://doi.org/10.1117/12.444913

KEYWORDS: Chlorine, Diffusion, Optical fibers, Silica, Absorption, Ultraviolet radiation, Hydrogen, Cladding, Doping, Fluorine

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Proceedings Article | 3 April 2000 Paper

Paper

8-W highly efficient Yb-doped fiber laser

Volker Reichel, Sonja Unger, Volker Hagemann, Hans-Rainer Mueller, Mario Auerbach

Proceedings Volume 3889, (2000) https://doi.org/10.1117/12.380877

KEYWORDS: Fiber lasers, Fiber Bragg gratings, Mirrors, Ytterbium, Resonators, Laser resonators, Optical fibers, Silica, Precision optics, Micromirrors

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In this paper a very compact device of a very efficient high- power fiber-laser based on a specially designed Ytterbium (Yb)-doped double-clad D-Shape silica fiber with an output power of more than 8 watts will be described. The development, preparation and characterization of rare-earth doped double- clad optical fibers based on silica for the application in high-power fiber-lasers were done at the Optics Division of the Institute for Physical High-Technology e.V. Jena (IPHT) in the last few years. The doping with Ytterbium as the laseractive component was one of the most important questions which were investigated. Many samples had to be made for the optimum concentration of Yb, the optimum codoping and geometry, respectively. As a result of these experiments we realized a double-clad fiber with D-shape geometry of the pump-core. This D-shape resulted from ray-tracing calculations performed at the Lasercentre Hannover e.V. (LZH) as an optimal solution for the high conversion efficiency of the pump-power. Considering these numerical results, such fibers were realized at IPHT by drawing a sidepolished preform by preserving the cross section of the preform. After some basic investigations on the optimum wavelength for the pump-light and the resonator length, respectively, a compact device with a launched pump- power of approx. 13 W and an output-power of more than 8 watts was developed and realized. The maximum output-power was only limited by the pump-power available at our laboratory at the chosen wavelength. Main advantages of the setup are the short length of the laseractive fiber (less than 10 m), the high efficiency (greater than 60%) and the compactness of the device. Additionally, the diameter of the pump-core was reduced to 125 micrometer. These kinds of fibers were tested with a specially designed pump-source of the Fraunhofer Institute for Applied Optics and Precision Engineering in Jena. The first result with a double-clad Yb-doped fiber of only 4 meter length was a fiber-laser with an output-power of about 4 Watts. Last but not least, some basic experiments with Fiber-Bragg-Gratings (FBG) as one of the resonator mirrors were done. A fiber-laser with a FBG for the laser-wavelength had an output-power of about 700 mW with a FWHM of about 0.1 nm.

Proceedings Article | 27 May 1998 Paper

Paper

High-power single-mode Nd-doped fiber laser

Volker Reichel, Sonja Unger, Hans-Rainer Mueller, Holger Zellmer

Proceedings Volume 3265, (1998) https://doi.org/10.1117/12.308672

KEYWORDS: Optical fibers, Fiber lasers, Silica, Luminescence, Signal attenuation, Multimode fibers, Mirrors, Refractive index, Germanium, Neodymium

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Showing 5 of 41 publications

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