Dr. David Ashkenasi Profile

Dr. David Ashkenasi

at Independent Consultant

SPIE Involvement:

Author

Publications (27)

Proceedings Article | 22 February 2017 Presentation + Paper

Presentation + Paper

Diode lasers for direct application by utilizing a trepanning optic for remote oscillation welding of aluminum and copper

Haro Fritsche, Norbert Müller, Fabio Ferrario, Sebastian Fetissow, Andreas Grohe, Thomas Hagen, Ronny Steger, Tristan Katzemaikat, David Ashkenasi, Wolfgang Gries

Proceedings Volume 10097, 100970N (2017) https://doi.org/10.1117/12.2253007

KEYWORDS: Aluminum, Semiconductor lasers, Copper, Collimation, Continuous wave operation, Laser systems engineering, Free space optics, Fiber coupled lasers, Free space, Materials processing

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We report the first direct diode laser module integrated with a trepanning optic for remote oscillation welding. The trepanning optic is assembled with a collimated DirectProcess 900 laser engine. This modular laser is based on single emitters and beam combiners to achieve fiber coupled modules with a beam parameter product or BPP < 8 mm mrad at all power levels up to 1 kW, as well as free space collimated outputs with even lower BPP. The initial design consists in vertically stacking several diodes in the fast axis which leads to a rectangular output of about 100 W with BPP of <3.5 mm*mrad in the fast axis and <5 mm*mrad in the slow axis. Next, further power scaling is accomplished by polarization combining and wavelength multiplexing yielding high optical efficiencies of more than 80% and resulting in a building block module with over 500 W launched into a 100 μm fiber with 0.15 NA. The beam profile of the free space module remains rectangular, with a nearly flat top and conserves the beam parameter product of the original vertical stack without the power loss of fiber coupling. The 500 W building blocks feature a highly flexible emitting wavelength bandwidth. New wavelengths can be configured by simply exchanging parts and without modifying the production process. This design principle provides the option to adapt the wavelength configuration to match a broad set of applications, from the UV to the visible and to the far IR depending on the commercial availability of laser diodes. This opens numerous additional applications like laser pumping, scientific and medical applications, as well as materials processing applications such as cutting and welding of copper aluminum or steel. Furthermore, the module’s short lead lengths enable very short pulses. Integrated with electronics, the module’s pulse width can be adjusted from micro-seconds to cw mode operation by simple software commands. An optical setup can be directly attached instead of a fiber to the laser module thanks to its modular design. This paper’s experimental results are based on a trepanning optic attached to the laser module. Alltogether the setup approximately fits in a shoe box and weighs less than 20 kg which allows for direct mounting onto a 3D-gantry system. The oscillating weld performance of the 500 W direct diode laser utilizing a novel trepanning optic is discussed for its application to aluminum/aluminum and aluminum/copper joints.

Proceedings Article | 18 February 2012 Paper

Paper

Rotating optics for laser taper-drilling in research and production

David Ashkenasi, Tristan Kaszemeikat, Norbert Mueller, Matthias Schmidt, Hans Joachim Eichler, Maurice Clair, Tino Petsch, Jens Hänel, Markus Lasch, Christian Scholz

Proceedings Volume 8244, 82440Q (2012) https://doi.org/10.1117/12.907726

KEYWORDS: Laser drilling, Laser cutting, Head, Laser processing, Laser systems engineering, Scanners, Aluminum, Laser applications, Pulsed laser operation, Ceramics

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Proceedings Article | 16 February 2012 Paper

Paper

Machining of glass and quartz using nanosecond and picosecond laser pulses

David Ashkenasi, Tristan Kaszemeikat, Norbert Mueller, Andreas Lemke, Hans Joachim Eichler

Proceedings Volume 8243, 82430M (2012) https://doi.org/10.1117/12.907740

KEYWORDS: Glasses, Laser processing, Laser cutting, Laser drilling, Picosecond phenomena, Quartz, Laser ablation, Laser applications, Laser glasses, Soda-lime glass

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Proceedings Article | 13 March 2007 Paper

Paper

DPSSL for direct dicing and drilling of dielectrics

David Ashkenasi, M. Schwagmeier

Proceedings Volume 6458, 64580F (2007) https://doi.org/10.1117/12.700129

KEYWORDS: Glasses, Laser processing, Laser cutting, Pulsed laser operation, Laser drilling, Borosilicate glass, Laser systems engineering, Laser ablation, Laser applications, Photonics

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Proceedings Article | 13 March 2007 Paper

Paper

Nonlinear response in optical materials using ultrashort laser technology

David Ashkenasi

Proceedings Volume 6458, 64580P (2007) https://doi.org/10.1117/12.700137

KEYWORDS: Glasses, Picosecond phenomena, Laser damage threshold, Pulsed laser operation, Optical filters, Laser applications, Ultraviolet radiation, Absorption, Laser energy, Nonlinear optics

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Proceedings Article | 15 July 2004 Paper

Paper

Laser-induced modification of the optical properties of transparent materials

David Ashkenasi, Kazem Ghaleh, Hans-Juergen Hoffmann

Proceedings Volume 5339, (2004) https://doi.org/10.1117/12.537599

KEYWORDS: Glasses, Silver, Optical filters, Pulsed laser operation, Laser damage threshold, Optical properties, Picosecond phenomena, Ions, Transmittance, Ultraviolet radiation

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Proceedings Article | 15 July 2004 Paper

Paper

High-power and high-brightness solid state laser systems for precise and fast micromachining

Alexander Binder, Houssam Jaber, David Ashkenasi, Thomas Riesbeck, Hans-J. Eichler

Proceedings Volume 5339, (2004) https://doi.org/10.1117/12.529418

KEYWORDS: Laser drilling, Laser systems engineering, Nd:YAG lasers, Aluminum nitride, Oscillators, Sapphire, Aluminum, Optical amplifiers, Ceramics, Metals

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Proceedings Article | 15 July 2004 Paper

Paper

High-efficiency microstructuring of VUV window materials by laser-induced plasma-assisted ablation (LIPAA) with a KrF excimer laser

Houssam Jaber, Alexander Binder, David Ashkenasi

Proceedings Volume 5339, (2004) https://doi.org/10.1117/12.529451

KEYWORDS: Silica, Laser ablation, Calcium, Excimer lasers, Fluorine, Ultraviolet radiation, Metals, Laser processing, Vacuum ultraviolet, Image processing

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Proceedings Article | 18 November 2003 Paper

Paper

Laser-induced sub-surface modification of the optical properties in transparent materials: nik-engineering (TM)

David Ashkenasi, Hans-Juergen Hoffmann, Gerhard Mueller

Proceedings Volume 5063, (2003) https://doi.org/10.1117/12.540695

KEYWORDS: Glasses, Silver, Pulsed laser operation, Picosecond phenomena, Optical properties, Ions, Chemical species, Ultraviolet radiation, Laser processing, Laser damage threshold

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Proceedings Article | 18 November 2003 Paper

Paper

Microdrilling, -scribing and cutting with high-quality and high-power ns-Nd:YAG systems

Alexander Binder, David Ashkenasi, Norbert Mueller, Thomas Riesbeck, Hans Eichler

Proceedings Volume 5063, (2003) https://doi.org/10.1117/12.540748

KEYWORDS: Laser drilling, Nd:YAG lasers, Laser systems engineering, Oscillators, Metals, Optical amplifiers, Sapphire, Ceramics, Laser ablation, Pulsed laser operation

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Proceedings Article | 18 November 2003 Paper

Paper

Ultra short laser pulse modification of wave guides

Arkadi Rosenfeld, David Ashkenasi

Proceedings Volume 5063, (2003) https://doi.org/10.1117/12.540763

KEYWORDS: Waveguides, Picosecond phenomena, Pulsed laser operation, Cladding, Interfaces, Laser processing, Silica, Microscopes, Light scattering, Scattering

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Proceedings Article | 17 October 2003 Paper

Paper

High-quality laser microdrilling of metals and ceramics with maximum aspect ratio

Alexander Binder, Thomas Metzger, Holger Kern, David Ashkenasi, Gerhard Mueller, Thomas Riesbeck, Hans Eichler

Proceedings Volume 4977, (2003) https://doi.org/10.1117/12.479235

KEYWORDS: Laser drilling, Nd:YAG lasers, Oscillators, Laser systems engineering, Aluminum nitride, Optical amplifiers, Metals, Ceramics, Aluminum, Laser ablation

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Proceedings Article | 17 October 2003 Paper

Paper

Subsurface 3D structures by laser-induced modification of the optical properties of transparent materials

David Ashkenasi, Hans-Juergen Hoffmann, Dieter Krause, Gerhard Mueller

Proceedings Volume 4977, (2003) https://doi.org/10.1117/12.479233

KEYWORDS: Glasses, Silver, Pulsed laser operation, Picosecond phenomena, Optical properties, Ions, Chemical species, Ultraviolet radiation, Laser processing, Refractive index

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Proceedings Article | 17 October 2003 Paper

Paper

High-brightness solid state laser systems with fiber phase conjugate mirrors for micro material processing

Thomas Riesbeck, Hans Eichler, Enrico Risse, Alexander Binder, David Ashkenasi, Gerhard Mueller

Proceedings Volume 4977, (2003) https://doi.org/10.1117/12.479409

KEYWORDS: Optical amplifiers, Oscillators, Nd:YAG lasers, Mirrors, Phase conjugation, Fiber amplifiers, Laser systems engineering, Crystals, Solid state lasers, Materials processing

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Proceedings Article | 17 October 2003 Paper

Paper

Laser processing of ceramic and crystalline wafer substrates for microelectronic applications

David Ashkenasi, Alexander Binder, Houssam Jaber, Holger Kern, Norbert Mueller, Andreas Ziegert

Proceedings Volume 4977, (2003) https://doi.org/10.1117/12.479234

KEYWORDS: Laser drilling, Aluminum nitride, Laser processing, Aluminum, Laser systems engineering, Semiconducting wafers, Nd:YAG lasers, Silicon carbide, Ceramics, Semiconductor lasers

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Proceedings Article | 19 June 2003 Paper

Paper

Ultrashort laser pulse processing of wave guides for medical applications

David Ashkenasi, Arkadi Rosenfeld, Stefan Spaniol, Albert Terenji

Proceedings Volume 4978, (2003) https://doi.org/10.1117/12.478583

KEYWORDS: Waveguides, Picosecond phenomena, Laser processing, Interfaces, Pulsed laser operation, Laser applications, Image processing, Laser scattering, Scattering, Cladding

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Proceedings Article | 13 September 2002 Paper

Paper

Fundamentals and advantages in ultrafast micro-structuring of transparent materials

David Ashkenasi, Arkadi Rosenfeld, Razvan Stoian, Nadezhda Bulgakova, Eleanor Campbell, Ingolf Hertel

Proceedings Volume 4760, (2002) https://doi.org/10.1117/12.482033

KEYWORDS: Laser ablation, Dielectrics, Ions, Pulsed laser operation, Metals, Aluminum, Laser processing, Laser applications, Picosecond phenomena, Ionization

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Proceedings Article | 18 June 2002 Paper

Paper

The potential of ultrashort laser pulses (<10ps) in future material processing: mode-locked Ti:sapphire vs. q-switch Nd:YAG applications

David Ashkenasi

Proceedings Volume 4637, (2002) https://doi.org/10.1117/12.470671

KEYWORDS: Laser processing, Pulsed laser operation, Laser applications, Laser drilling, Nd:YAG lasers, Q switching, Picosecond phenomena, Laser systems engineering, Tungsten, Q switched lasers

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Proceedings Article | 18 June 2002 Paper

Paper

Processing multilayer systems using femtosecond, picosecond, and nanosecond laser pulses at different wavelengths

David Ashkenasi, Arkadi Rosenfeld

Proceedings Volume 4637, (2002) https://doi.org/10.1117/12.470619

KEYWORDS: Glasses, Laser damage threshold, Laser processing, Pulsed laser operation, Laser ablation, Picosecond phenomena, Absorption, Femtosecond phenomena, Ultraviolet radiation, Optical microscopes

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Proceedings Article | 1 April 2002 Paper

Paper

Laser-induced incubation in transparent materials and possible consequences for surface and bulk micro-structuring with ultrashort pulses

David Ashkenasi, Arkadi Rosenfeld, Razvan Stoian

Proceedings Volume 4633, (2002) https://doi.org/10.1117/12.461367

KEYWORDS: Picosecond phenomena, Laser damage threshold, Pulsed laser operation, Laser ablation, Ions, Laser processing, Femtosecond phenomena, Laser energy, Silica, Absorption

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Proceedings Article | 25 February 2002 Paper

Paper

Ultrafast laser ablation of dielectrics employing temporally shaped femtosecond pulses

Razvan Stoian, Mark Boyle, Andreas Thoss, Arkadi Rosenfeld, David Ashkenasi, Georg Korn, Eleanor Campbell, Ingolf Hertel

Proceedings Volume 4426, (2002) https://doi.org/10.1117/12.456853

KEYWORDS: Electrons, Dielectrics, Silica, Sapphire, Laser ablation, Picosecond phenomena, Femtosecond phenomena, Ions, Particles, Laser damage threshold

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Proceedings Article | 6 November 2000 Paper

Paper

Surface and bulk ultrashort-pulsed laser processing of transparent materials

Ingolf Hertel, Razvan Stoian, David Ashkenasi, Arkadi Rosenfeld, Eleanor Campbell

Proceedings Volume 4088, (2000) https://doi.org/10.1117/12.405703

KEYWORDS: Ions, Laser ablation, Electrons, Etching, Pulsed laser operation, Picosecond phenomena, Particles, Sapphire, Ionization, Velocity measurements

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Proceedings Article | 7 February 2000 Paper

Paper

Beam propagation of high-power ultrashort laser pulses inside transparent dielectrics for controlled 3D microstructuring

David Ashkenasi, Markus Lorenz, Arkadi Rosenfeld

Proceedings Volume 3888, (2000) https://doi.org/10.1117/12.377007

KEYWORDS: Picosecond phenomena, Ultrafast phenomena, Pulsed laser operation, Laser energy, Laser induced fluorescence, Laser beam propagation, Laser processing, Femtosecond phenomena, High power lasers, Laser damage threshold

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Proceedings Article | 1 February 2000 Paper

Paper

Laser ablation of sapphire with ultrashort pulses

Razvan Stoian, David Ashkenasi, Arkadi Rosenfeld, Eleanor Campbell

Proceedings Volume 3885, (2000) https://doi.org/10.1117/12.376955

KEYWORDS: Ions, Laser ablation, Picosecond phenomena, Pulsed laser operation, Laser damage threshold, Etching, Sapphire, Ultrafast phenomena, Aluminum, Dielectrics

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Proceedings Article | 15 July 1999 Paper

Paper

Material processing of dielectrics with femtosecond lasers

David Ashkenasi, Arkadi Rosenfeld

Proceedings Volume 3618, (1999) https://doi.org/10.1117/12.352675

KEYWORDS: Laser damage threshold, Pulsed laser operation, Picosecond phenomena, Dielectrics, Femtosecond phenomena, Laser energy, Laser processing, Silica, Solids, Materials processing

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Proceedings Article | 14 September 1998 Paper

Paper

Laser ablation and structuring of transparent materials with ultrashort laser pulses

David Ashkenasi, Gerril Herbst, Arkadi Rosenfeld, H. Varel, Michael Lorenz, Razvan Stoian, Eleanor Campbell

Proceedings Volume 3343, (1998) https://doi.org/10.1117/12.321575

KEYWORDS: Pulsed laser operation, Picosecond phenomena, Sapphire, Laser processing, Laser ablation, Ultrafast phenomena, Electrons, Etching, Silica, Laser damage threshold

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Proceedings Article | 15 April 1993 Paper

Paper

Compact design of a femtosecond single-shot autocorrelator

David Ashkenasi

Proceedings Volume 1780, 17801N (1993) https://doi.org/10.1117/12.142856

KEYWORDS: Crystals, Pulsed laser operation, Picosecond phenomena, Femtosecond phenomena, Laser systems engineering, CCD cameras, Sensors, Optical design, Signal detection, Calibration

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Showing 5 of 27 publications

Conference Committee Involvement (2)

Laser Applications in Microelectronic and Optoelectronic Manufacturing IX

26 January 2004 | San Jose, Ca, United States

Laser Applications in Microelectronics and Optoelectronic Manufacturing VIII

27 January 2003 | San Jose, CA, United States

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