Mr. Tobias Könning Profile

Tobias Könning

Senior Engineering Manager at Coherent Mainz

SPIE Involvement:

Author

Area of Expertise:

optical design , high power diode lasers , fiber coupling , project management

Publications (18)

Proceedings Article | 4 March 2022 Presentation + Paper

Presentation + Paper

Advances in fiber coupled high power diode laser modules at 793nm and 976nm for defense applications

Tobias Könning, Sandra Ahlert, Jan Weimar, Ruth Steinborn-Knuth, Florian Ahnepohl, Heiko Kissel, Bernd Köhler, Markus Klein, Guoli Liu, Sami Lehkonen

Proceedings Volume 11983, 119830I (2022) https://doi.org/10.1117/12.2606176

KEYWORDS: Fiber couplers, Fiber coupled lasers, Defense and security, Copper, Semiconductor lasers, Fiber lasers, High power diode lasers, Electro optics, Ytterbium, Laser applications

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Proceedings Article | 5 March 2021 Presentation + Paper

Presentation + Paper

Wavelength stabilized fiber coupled modules at 79x nm, 88x nm, and 97x nm with up to 600W output power based on single emitters

Tobias Könning, Sandra Ahlert, Jan Weimar, Ruth Steinborn-Knuth, Florian Ahnepohl, Heiko Kissel, Bernd Köhler, Guoli Liu, Sami Lehkonen

Proceedings Volume 11668, 116680F (2021) https://doi.org/10.1117/12.2577691

KEYWORDS: Fiber couplers, High power diode lasers, Fiber coupled lasers, Ytterbium, Thulium, Safety, Ranging, Power supplies, Polymers, Optical components

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Proceedings Article | 2 March 2020 Presentation + Paper

Presentation + Paper

Kilowatt-class high power fiber-coupled diode lasers at 450nm

Tobias Könning, Florian Harth, Philipp König, Paul Wolf, Michael Stoiber, Heiko Kissel, Bernd Köhler

Proceedings Volume 11262, 112620N (2020) https://doi.org/10.1117/12.2545887

KEYWORDS: Semiconductor lasers, Fiber lasers, Fiber coupled lasers, Near infrared, Fiber couplers, Laser development, Copper, Laser welding, Multiplexing, Diodes

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Proceedings Article | 4 March 2019 Presentation + Paper

Presentation + Paper

High brightness fiber coupled diode lasers at 450 nm

Tobias Könning, Simon Drovs, Michael Stoiber, Philipp König, Heiko Kissel, Florian Harth, Bernd Köhler, Jens Biesenbach, Harald König, Alfred Lell, Bernhard Stojetz, Muhammad Ali, Uwe Strauss

Proceedings Volume 10900, 1090006 (2019) https://doi.org/10.1117/12.2507462

KEYWORDS: Semiconductor lasers, Fiber lasers, Laser development, Fiber couplers, Fiber coupled lasers, Multiplexing, High power diode lasers, Copper, Manufacturing, Polarization

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Proceedings Article | 20 February 2018 Paper

Paper

Modular high power diode lasers with flexible 3D multiplexing arrangement optimized for automated manufacturing

Tobias Könning, Andreas Bayer, Nora Plappert, Wilhelm Faßbender, Sascha Dürsch, Matthias Küster, Ralf Hubrich, Paul Wolf, Bernd Köhler, Jens Biesenbach

Proceedings Volume 10513, 105130I (2018) https://doi.org/10.1117/12.2290554

KEYWORDS: Materials processing, Multiplexing, Polarization, Mirrors, Semiconductor lasers, Prisms, High power diode lasers, Optical components, Fiber couplers, Laser beam propagation, Fiber coupled lasers

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Proceedings Article | 19 February 2018 Presentation + Paper

Presentation + Paper

Visible high power fiber coupled diode lasers

Bernd Köhler, Simon Drovs, Michael Stoiber, Sascha Dürsch, Heiko Kissel, Tobias Könning, Jens Biesenbach, Harald König, Alfred Lell, Bernhard Stojetz, Andreas Löffler, Uwe Strauß

Proceedings Volume 10514, 1051408 (2018) https://doi.org/10.1117/12.2291397

KEYWORDS: Semiconductor lasers, Fiber couplers, Fiber coupled lasers, Collimation, Diodes, Electro optics, Optical components, Polarization, Laser development, Visible radiation

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Proceedings Article | 22 February 2017 Presentation + Paper

Presentation + Paper

Reliable QCW diode laser arrays for operation with high duty cycles

Wilhelm Fassbender, Heiko Kissel, Jens Lotz, Tobias Koenning, Steve Patterson, Jens Biesenbach

Proceedings Volume 10085, 1008509 (2017) https://doi.org/10.1117/12.2253837

KEYWORDS: Semiconductor lasers, Diodes, Surgery, High power lasers, Reliability, Packaging, Pulsed laser operation, Laser applications, Temperature metrology, Laser welding, Ceramics, Indium, Collimation, Copper, Thermography

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Proceedings Article | 22 February 2017 Presentation + Paper

Presentation + Paper

Optical components for tailoring beam properties of multi-kW diode lasers

Tobias Könning, Bernd Köhler, Paul Wolf, Andreas Bayer, Ralf Hubrich, Christian Bodem, Nora Plappert, Tobias Kindervater, Wilhelm Faßbender, Sascha Dürsch, Matthias Küster, Jens Biesenbach

Proceedings Volume 10085, 100850G (2017) https://doi.org/10.1117/12.2253793

KEYWORDS: Collimation, Semiconductor lasers, Optical components, Fiber coupled lasers, Fiber couplers, Fiber lasers, Beam shaping, Packaging, High power diode lasers, Materials processing, Laser stabilization, Laser development, Optics manufacturing

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Proceedings Article | 4 March 2016 Paper

Paper

DPAL pump system exceeding 3kW at 766nm and 30 GHz bandwidth

Tobias Koenning, Dan McCormick, David Irwin, Dean Stapleton, Tina Guiney, Steve Patterson

Proceedings Volume 9733, 97330E (2016) https://doi.org/10.1117/12.2213673

KEYWORDS: High power diode lasers, Diodes, Semiconductor lasers, Potassium, Diode pumped solid state lasers, Defense and security, Alkali metals, Alkali vapor lasers, Cesium, Rubidium, Fiber couplers, Calibration, Fiber coupled lasers, Lithium, Interfaces, Neodymium

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Proceedings Article | 13 March 2015 Paper

Paper

Narrow-line fiber-coupled modules for DPAL pumping

Tobias Koenning, Dan McCormick, David Irvin, Dean Stapleton, Tina Guiney, Steve Patterson

Proceedings Volume 9348, 934805 (2015) https://doi.org/10.1117/12.2082654

KEYWORDS: Reflectivity, High power diode lasers, Absorption, Semiconductor lasers, Diodes, Neodymium, Thermal modeling, Fiber lasers, Lithium, Fiber couplers

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Proceedings Article | 7 March 2014 Paper

Paper

High-resolution spectral mapping of a lensed high power laser bar

Caleb Gannon, Tobias Koenning, Steve Patterson, Paul Leisher

Proceedings Volume 8965, 896519 (2014) https://doi.org/10.1117/12.2040400

KEYWORDS: Semiconductor lasers, High power lasers, Absorption, Diodes, Collimation, Volume holography, Holography, Spatial filters, Spectrum analysis, Signal to noise ratio

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Proceedings Article | 25 February 2014 Paper

Paper

Narrow line diode laser stacks for DPAL pumping

Tobias Koenning, David Irwin, Dean Stapleton, Rajiv Pandey, Tina Guiney, Steve Patterson

Proceedings Volume 8962, 89620F (2014) https://doi.org/10.1117/12.2044723

KEYWORDS: Semiconductor lasers, Absorption, Diodes, High power diode lasers, Temperature metrology, Rubidium, Lithium, Electroluminescence, Alkali metals, Manufacturing

Read Abstract +

Diode pumped alkali metal vapor lasers (DPALs) offer the promise of scalability to very high average power levels while maintaining excellent beam quality, making them an attractive candidate for future defense applications. A variety of gain media are used and each requires a different pump wavelength: near 852nm for cesium, 780nm for rubidium, 766nm for potassium, and 670nm for lithium atoms. The biggest challenge in pumping these materials efficiently is the narrow gain media absorption band of approximately 0.01nm. Typical high power diode lasers achieve spectral widths around 3nm (FWHM) in the near infrared spectrum. With state of the art locking techniques, either internal to the cavity or externally mounted gratings, the spectral width can typically be reduced to 0.5nm to 1nm for kW-class, high power stacks. More narrow spectral width has been achieved at lower power levels. The diode’s inherent wavelength drift over operating temperature and output power is largely, but not completely, eliminated. However, standard locking techniques cannot achieve the required accuracy on the location of the spectral output or the spectral width for efficient DPAL pumping. Actively cooled diode laser stacks with continuous wave output power of up to 100W per 10mm bar at 780nm optimized for rubidium pumping will be presented. Custom designed external volume holographic gratings (VHGs) in conjunction with optimized chip material are used to narrow and stabilize the optical spectrum. Temperature tuning on a per-bar-level is used to overlap up to fifteen individual bar spectra into one narrow peak. At the same time, this tuning capability can be used to adjust the pump wavelength to match the absorption band of the active medium. A spectral width of <0.1nm for the entire stack is achieved at <1kW optical output power. Tuning of the peak wavelength is demonstrated for up to 0.15nm. The technology can easily be adapted to other diode laser wavelengths to pump different materials.

Proceedings Article | 26 February 2013 Paper

Paper

Characterization of laser diodes under short-pulsed conditions with high pulse energies

Tobias Koenning, Evan Hale, David Irwin, Kim Alegria, Steve Patterson

Proceedings Volume 8605, 860503 (2013) https://doi.org/10.1117/12.2005059

KEYWORDS: Semiconductor lasers, Fiber couplers, Laser damage threshold, Diodes, Near field optics, Near field, Fiber coupled lasers, Optical design, Pulsed laser operation

Read Abstract +

New applications require diode lasers to be driven with short pulses in the sub-micro second range. The goal is to minimize both the cost and size of the diode laser module by minimizing the number of laser bars required while maintaining the lifetime that is desired for the application. Products demanded by the market using such short pulses range from QCW stacks to fiber coupled modules. While many short pulsed applications use high fill factor bars, these bars are not suited for high brightness applications or coupling into small fiber cores. The focus of this work is the analysis of CW diode designs commonly used for high brightness fiber coupled modules under short pulsed conditions.

Three key parameters need to be known in order to design a diode laser module that is suited for high peak powers. First is the damage threshold of the facet. The damage threshold determines the maximum power level at which the laser can be operated safely, considering a proper safety margin dependent on application. The damage threshold is a function of the input pulse width and amplitude. The second parameter which is influenced by the drive current is the slow axis divergence of the diode laser. Knowledge of this parameter is critical when designing the system optics. The third parameter is the effective emitter size which may increase with operating current. An increase in emitter size will lead to larger divergences after collimating optics for a given focal length lens and may result in a larger spot when coupling into an optical fiber. All these parameters have to be considered when designing a new product.

Presented here is a study on these three critical parameters as a function of operating conditions. Results for different diode designs will be presented. The data presented includes damage thresholds, as well as near field and far field data at various operating currents. A design study for fiber coupled modules with high pulse energies based on the test results will be shown for various wavelengths.

Proceedings Article | 26 February 2013 Paper

Paper

Reliable QCW diode laser arrays for operation with high duty cycles

Heiko Kissel, Wilhelm Faßbender, Jens Lotz, Kim Alegria, Tobias Koenning, Dean Stapleton, Steve Patterson, Jens Biesenbach

Proceedings Volume 8605, 86050V (2013) https://doi.org/10.1117/12.2004399

KEYWORDS: Ceramics, Pulsed laser operation, Semiconductor lasers, Temperature metrology, Reliability, Diodes, Copper, Laser applications, Surgery, Laser welding

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Proceedings Article | 7 May 2012 Paper

Paper

Enhanced fiber coupled laser power and brightness for defense applications through tailored diode and thermal design

Steve Patterson, Tobias Koenning, Bernd Köhler, Sandra Ahlert, Andreas Bayer, Heiko Kissel, Holger Müntz, Axel Noeske, Karsten Rotter, Armin Segref, Michael Stoiber, Andreas Unger, Paul Wolf, Jens Biesenbach

Proceedings Volume 8381, 83810L (2012) https://doi.org/10.1117/12.922867

KEYWORDS: Semiconductor lasers, Fiber lasers, Fiber couplers, Fiber coupled lasers, Diodes, Defense and security, Polarization, Electro optics, Laser development, Defense technologies

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Advances in both diode laser design and packaging technology, particularly thermal management, are needed to enhance the brightness of fiber coupled diode lasers while maintaining the small size and light weight required for defense applications. The principles of design for high efficiency fiber coupling are briefly covered. Examples are provided of fielded and demonstrated 100 and 200 micron diameter fiber coupled packages ranging in output from a few hundred to kW-class units in fibers, to include sub-kg/kW capabilities. The demand for high-power and high-brightness fiber coupled diode laser devices is mainly driven by applications for solid-state and fiber laser pumping. The ongoing power scaling of fiber lasers requires scalable fiber-coupled diode laser devices with increased power and brightness. A modular diode laser concept combining high power, high brightness, wavelength stabilization and low weight, which is considerable concern in the SWaP trades needed to field defense systems, has been developed. In particular the defense technology requires robust but lightweight high-power diode laser sources in combination with high brightness. The heart of the concept is a specially tailored diode laser bar, with the epitaxial and lateral structures designed such that only standard fast- and slow-axis collimator lenses in combination with appropriate focusing optics are required to couple the beam into a fiber with a core diameter of 200 μm and a numerical aperture (NA) of 0.22. The spectral quality, which is an important issue especially for fiber laser pump sources, is ensured by means of Volume Holographic Gratings (VHG) for wavelength stabilization. This paper presents a detailed characterization of different diode laser sources based on the scalable modular concept. The optical output power is scaled from 180 W coupled into a 100 μm NA 0.22 fiber up to 800W coupled into a 400 μm NA 0.22 fiber. In addition we present a lightweight laser unit with an output power of more than 300 W for a 200 μm NA 0.22 fiber with a weight vs. power ratio of only 0.9 kg/kW.

Proceedings Article | 9 February 2012 Paper

Paper

kW-class line sources for direct applications

Tobias Koenning, Kim Alegria, Zuolan Wang, Dean Stapleton, Steve Patterson, Bernd Koehler, Jens Biesenbach

Proceedings Volume 8241, 824105 (2012) https://doi.org/10.1117/12.911816

KEYWORDS: Telescopes, Semiconductor lasers, Fiber couplers, Optical design, Collimation, Beam shaping, High power diode lasers, Electro optics, Manufacturing, Interfaces

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Proceedings Article | 21 February 2011 Paper

Paper

Fiber coupled diode laser beam parameter product calculation and rules for optimized design

Zuolan Wang, Simon Drovs, Armin Segref, Tobias Koenning, Rajiv Pandey

Proceedings Volume 7918, 791809 (2011) https://doi.org/10.1117/12.875386

KEYWORDS: Diodes, Fiber lasers, Fiber couplers, Semiconductor lasers, Fiber coupled lasers, Optical design, Beam shaping, Optical simulations, Nomenclature, Technologies and applications

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Proceedings Article | 21 February 2011 Paper

Paper

Macro-channel cooled high power fiber coupled diode lasers exceeding 1.2kW of output power

Tobias Koenning, Kim Alegria, Zuolan Wang, Armin Segref, Dean Stapleton, Wilhelm Faßbender, Marco Flament, Karsten Rotter, Axel Noeske, Jens Biesenbach

Proceedings Volume 7918, 79180E (2011) https://doi.org/10.1117/12.875795

KEYWORDS: Semiconductor lasers, Fiber lasers, Fiber coupled lasers, Fiber couplers, Laser development, Resistance, Prisms, High power fiber coupled lasers, Polarization, Optical design

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Showing 5 of 18 publications

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