Mr. David A. Irwin Profile

David A. Irwin

at Hart Scientific Consulting International LLC

SPIE Involvement:

Author

Publications (13)

Proceedings Article | 21 May 2018 Paper

Narrow-band and low SWaP diodes in tough environments

David Irwin, Dean Stapleton, Golchehr Noshirvani, Tina Guiney, Joseph Braker, Kim Alegria, Chris Ebert, Lukas Gruber

Proceedings Volume 10637, 1063709 (2018) https://doi.org/10.1117/12.2304497

KEYWORDS: Diodes, Directed energy weapons, Fiber lasers, Energy efficiency, Semiconductor lasers, Absorption

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Proceedings Article | 14 March 2018 Presentation

Alternate cooling and use schemes for low SWaP fiber pump modules (Conference Presentation)

David Irwin, Joseph Braker, Tina Guiney, Naji Barakat, Chris Ebert

Proceedings Volume 10514, 1051412 (2018) https://doi.org/10.1117/12.2291372

KEYWORDS: Diodes, Fiber lasers, Cooling systems, High power lasers, Defense and security, Energy efficiency, Directed energy weapons, Laser development, High power fiber lasers, Semiconductor lasers

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Proceedings Article | 1 May 2017 Presentation + Paper

High-power pump diodes for defense applications

Chris Ebert, Tina Guiney, Joe Braker, Dean Stapleton, Kim Alegria, David Irwin

Proceedings Volume 10192, 101920D (2017) https://doi.org/10.1117/12.2265028

KEYWORDS: Diodes, Fiber couplers, Fiber coupled lasers, Computer aided design, Calibration, Fiber lasers, High power lasers, Semiconductor lasers, Thulium, Ytterbium, Defense and security, Control systems

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Proceedings Article | 21 April 2017 Presentation

Advances in 7xx-nm fiber-coupled modules with application to Tm fiber laser pumping and DPAL (Conference Presentation)

Steven Patterson, Tina Guiney, Dean Stapleton, Joseph Braker, Kim Alegria, David Irwin, Christopher Ebert

Proceedings Volume 10086, 100860I (2017) https://doi.org/10.1117/12.2253001

KEYWORDS: Laser applications, Current controlled current source, Thulium, Fiber lasers, Semiconductor lasers, Manufacturing, Defense technologies, High power lasers

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Proceedings Article | 22 February 2017 Presentation + Paper

Advances in the power, brightness, weight and efficiency of fiber-coupled diode lasers for pumping and direct diode applications

Chris Ebert, Tina Guiney, Joe Braker, Dean Stapleton, Kim Alegria, David Irwin

Proceedings Volume 10086, 1008607 (2017) https://doi.org/10.1117/12.2253116

KEYWORDS: Semiconductor lasers, Diodes, Fiber lasers, Defense technologies, Fiber coupled lasers, Fiber couplers, High power lasers, Prototyping, Computer aided design, Laser marking, Laser applications, Polarization

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Proceedings Article | 13 May 2016 Paper

New advancements in 793 nm fiber-coupled modules for Th fiber laser pumping, including packages optimized for low SWaP applications

Chris Ebert, Tina Guiney, David Irwin, Steve Patterson

Proceedings Volume 9834, 98340J (2016) https://doi.org/10.1117/12.2223127

KEYWORDS: Fiber lasers, Thulium, Fiber coupled lasers, Fiber couplers, Diodes, Absorption, Semiconductor lasers, YAG lasers, Infrared countermeasures, Laser applications

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Proceedings Article | 13 May 2016 Paper

Fiber-coupled modules producing >300W and >600W from a 225 micron fiber, with <0.7 kg/kW weight-power ratio

Chris Ebert, David Irwin, Tina Guiney, Dean Stapleton, Steve Patterson

Proceedings Volume 9834, 98340I (2016) https://doi.org/10.1117/12.2222908

KEYWORDS: Semiconductor lasers, Diodes, Fiber lasers, Fiber couplers, Fiber coupled lasers, Laser applications, Prototyping, Computer aided design, Optics manufacturing, Resistance

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Proceedings Article | 4 March 2016 Paper

Multi-kW high-brightness fiber coupled diode laser based on two dimensional stacked tailored diode bars

Andreas Bayer, Andreas Unger, Bernd Köhler, Matthias Küster, Sascha Dürsch, Heiko Kissel, David Irwin, Christian Bodem, Nora Plappert, Maik Kersten, Jens Biesenbach

Proceedings Volume 9733, 97330A (2016) https://doi.org/10.1117/12.2212695

KEYWORDS: Semiconductor lasers, Fiber coupled lasers, Fiber couplers, Fiber lasers, Diodes, Materials processing, Multiplexing, Reliability, Beam shaping, Metals, Computer aided design, Laser development, Laser sources

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Proceedings Article | 4 March 2016 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 | 7 March 2014 Paper

Scalable and modular diode laser architecture for fiber coupling that combines high-power, high-brightness, and low weight

Andreas Bayer, Bernd Köhler, Axel Noeske, Matthias Küster, David Irwin, Steve Patterson, Jens Biesenbach

Proceedings Volume 8965, 89650J (2014) https://doi.org/10.1117/12.2038959

KEYWORDS: Semiconductor lasers, Fiber lasers, Fiber couplers, Fiber coupled lasers, Diodes, High power lasers, Polarization, Materials processing, Laser development, Collimators

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Proceedings Article | 25 February 2014 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

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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 | 23 May 2013 Paper

Narrow-line, tunable, high-power diode laser pump for DPAL applications

Rajiv Pandey, David Merchen, Dean Stapleton, David Irwin, Chuck Humble, Steve Patterson, Heiko Kissel, Jens Biesenbach

Proceedings Volume 8733, 873307 (2013) https://doi.org/10.1117/12.2014301

KEYWORDS: Semiconductor lasers, Diodes, Diffraction, Diffraction gratings, Fiber Bragg gratings, High power lasers, Collimation, Temperature metrology, Rubidium

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Proceedings Article | 26 February 2013 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

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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.

Showing 5 of 13 publications

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