Dr. Gerhard Schötz Profile

Dr. Gerhard Schötz

Global Head of Specialty Fiber, Senior VP at Heraeus Quarzglas GmbH

SPIE Involvement:

Author

Publications (16)

Proceedings Article | 15 March 2023 Presentation + Paper

Fused silica step-index fibers tailored for applications from UV to IR wavelength range

Andreas Langner, Maximilian Fischer, Peter Bauer, Gerhard Schötz

Proceedings Volume 12414, 124140I (2023) https://doi.org/10.1117/12.2667909

KEYWORDS: Silica, Cladding, Ultraviolet radiation, Industrial applications, Signal attenuation, Fiber lasers, Specialty optical fibers, Refractive index, Biomedical applications, Visible radiation

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Proceedings Article | 5 March 2021 Presentation + Paper

Trends in specialty fiber optic materials: characterization and applications

Andreas Langner, Peter Bauer, Dörte Schönfeld, Bodo Kühn, Maximilian Schmitt, Gerhard Schötz

Proceedings Volume 11635, 1163506 (2021) https://doi.org/10.1117/12.2576252

KEYWORDS: Specialty optical fibers, Optical fibers, Silica, Optics manufacturing, Visible radiation, Ultraviolet radiation, Surgery, Step index fibers, Solids

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Proceedings Article | 7 March 2019 Paper

Improvement of the manufacturing process chain of sintered active XLMA fibers and their preforms for use in high power, high efficiency fiber resonators

A. Langner, F. Moser, J. Plass, D. Schönfeld, G. Schötz, T. Brabant, G. Kuka, M. Giesberts, P. Baer, S. Klein, O. Fitzau, H.-D. Hoffmann, G. Rehmann, V. Krause

Proceedings Volume 10897, 108970F (2019) https://doi.org/10.1117/12.2508597

KEYWORDS: Optical fibers, Fiber lasers, Scattering, Luminescence, Light scattering, Manufacturing, Refractive index, Silica, Cladding, Ytterbium, Rare earth doped glasses, Silicate glass

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Proceedings Article | 22 July 2016 Paper

Fused silica challenges in sensitive space applications

Josephine Criddle, Frank Nürnberg, Robert Sawyer, Peter Bauer, Andreas Langner, Gerhard Schötz

Proceedings Volume 9912, 99120K (2016) https://doi.org/10.1117/12.2231661

KEYWORDS: Silica, Spectroscopy, Astronomy, Optical fibers, Mirrors, Telescopes, Visible radiation, LIGO, Space telescopes, Reflectors

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Proceedings Article | 23 November 2015 Paper

Bulk damage and absorption in fused silica due to high-power laser applications

F. Nürnberg, B. Kühn, A. Langner, M. Altwein, G. Schötz, R. Takke, S. Thomas, J. Vydra

Proceedings Volume 9632, 96321R (2015) https://doi.org/10.1117/12.2194289

KEYWORDS: Absorption, Silica, Energy, Optical components, Deep ultraviolet, Ultraviolet radiation, Laser welding, Infrared radiation, Laser applications, Laser optics, Optical fibers, Fiber lasers, Refractive index, Photons, Silicon, Signal attenuation, High power lasers

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Laser fusion projects are heading for IR optics with high broadband transmission, high shock and temperature resistance, long laser durability, and best purity. For this application, fused silica is an excellent choice. The energy density threshold on IR laser optics is mainly influenced by the purity and homogeneity of the fused silica. The absorption behavior regarding the hydroxyl content was studied for various synthetic fused silica grades. The main absorption influenced by OH vibrational excitation leads to different IR attenuations for OH-rich and low-OH fused silica.

Industrial laser systems aim for the maximum energy extraction possible. Heraeus Quarzglas developed an Yb-doped fused silica fiber to support this growing market. But the performance of laser welding and cutting systems is fundamentally limited by beam quality and stability of focus. Since absorption in the optical components of optical systems has a detrimental effect on the laser focus shift, the beam energy loss and the resulting heating has to be minimized both in the bulk materials and at the coated surfaces. In collaboration with a laser research institute, an optical finisher and end users, photo thermal absorption measurements on coated samples of different fused silica grades were performed to investigate the influence of basic material properties on the absorption level.

High purity, synthetic fused silica is as well the material of choice for optical components designed for DUV applications (wavelength range 160 nm - 260 nm). For higher light intensities, e.g. provided by Excimer lasers, UV photons may generate defect centers that effect the optical properties during usage, resulting in an aging of the optical components (UV radiation damage). Powerful Excimer lasers require optical materials that can withstand photon energy close to the band gap and the high intensity of the short pulse length. The UV transmission loss is restricted to the DUV wavelength range below 300 nm and consists of three different absorption bands centered at 165 nm (peroxy radicals), 215 nm (E’-center), and 265 nm (non-bridging oxygen hole center (NBOH)), which change the transmission behavior of material.

Proceedings Article | 16 March 2015 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 | 7 March 2014 Paper

Plasma outside deposition (POD) of fluorine doped silica for high-power laser applications

Andreas Langner, Gerhard Schötz

Proceedings Volume 8961, 896115 (2014) https://doi.org/10.1117/12.2041745

KEYWORDS: Silica, Cladding, Optical fibers, Fiber lasers, Fluorine, Glasses, Refractive index, Specialty optical fibers, Signal attenuation, Plasma

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Proceedings Article | 22 February 2013 Paper

Design evolution, long term performance and application tests of extra large mode area (XLMA) fiber lasers

Andreas Langner, Mario Such, Gerhard Schötz, Florian Just, Martin Leich, Stephan Grimm, Jan Dellith, Matthias Jäger, Kay Schuster, Hagen Zimer, Marcin Kozak, Björn Wedel, Georg Rehmann, Charley Bachert, Volker Krause

Proceedings Volume 8601, 86010G (2013) https://doi.org/10.1117/12.2000472

KEYWORDS: Fiber lasers, Silica, Absorption, Ytterbium, Cladding, Coating, Aluminum, Backscatter, Laser systems engineering, Doping

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Proceedings Article | 16 February 2012 Paper

Multi-kW single fiber laser based on an extra large mode area fiber design

Andreas Langner, Mario Such, Gerhard Schötz, Florian Just, Martin Leich, Anka Schwuchow, Stephan Grimm, Hagen Zimer, Marcin Kozak, Björn Wedel, Georg Rehmann, Charley Bachert, Volker Krause

Proceedings Volume 8237, 82370F (2012) https://doi.org/10.1117/12.904951

KEYWORDS: Fiber lasers, Silica, Cladding, Signal attenuation, Doping, Refractive index, Absorption, Ytterbium, Laser systems engineering, Laser welding

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Proceedings Article | 11 February 2011 Paper

New developments in high power fiber lasers based on alternative materials

Andreas Langner, Mario Such, Gerhard Schötz, Stephan Grimm, Florian Just, Martin Leich, Christian Mühlig, Jens Kobelke, Anka Schwuchow, Oliver Mehl, Olaf Strauch, Roman Niedrig, Björn Wedel, Georg Rehmann, Volker Krause

Proceedings Volume 7914, 79141U (2011) https://doi.org/10.1117/12.876978

KEYWORDS: Fiber lasers, Silica, Cladding, Signal attenuation, Refractive index, Absorption, Laser induced damage, Doping, Ytterbium, Laser development

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Proceedings Article | 29 November 2010 Paper

Characterization of preform raw materials for high power fiber lasers using LID absorption measurement technique

Ch. Mühlig, S. Bublitz, St. Grimm, A. Langner, G. Schötz

Proceedings Volume 7842, 78421M (2010) https://doi.org/10.1117/12.867230

KEYWORDS: Absorption, Raw materials, Laser induced damage, Fiber lasers, Silica, Calibration, Scattering, Signal attenuation, Laser scattering, Manufacturing

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Proceedings Article | 17 February 2010 Paper

Development, manufacturing and lasing behavior of Yb-doped ultra large mode area fibers based on Yb-doped fused bulk silica

Andreas Langner, Mario Such, Gerhard Schötz, Volker Reichel, Stephan Grimm, Florian Just, Martin Leich, Johannes Kirchhof, Björn Wedel, Gunnar Köhler, Olaf Strauch, Oliver Mehl, Volker Krause, Georg Rehmann

Proceedings Volume 7580, 75802X (2010) https://doi.org/10.1117/12.845761

KEYWORDS: Cladding, Silica, Optical fibers, Fiber lasers, Refractive index, Doping, Connectors, Semiconductor lasers, Ions, Glasses

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Proceedings Article | 19 February 2009 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 | 22 February 2008 Paper

A new material for high-power laser fibers

Andreas Langner, Gerhard Schötz, Mario Such, Thomas Kayser, Volker Reichel, Stephan Grimm, Johannes Kirchhof, Volker Krause, Georg Rehmann

Proceedings Volume 6873, 687311 (2008) https://doi.org/10.1117/12.761671

KEYWORDS: Fiber lasers, Optical fibers, Silica, Cladding, Signal attenuation, Refractive index, Doping, Fluorine, Semiconductor lasers, Laser development

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