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Your search keyword '"Maaßdorf, A."' showing total 386 results
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386 results on '"Maaßdorf, A."'

1. Continuous wave operation of broad area and ridge waveguide laser diodes at 626 nm

Author

Felix Mauerhoff, Oktay Senel, Hans Wenzel, André Maaßdorf, Jos Boschker, Johannes Glaab, Katrin Paschke, and Günther Tränkle

Subjects
III‐V semiconductors, fabry‐perot resonators, MOCVD, semiconductor epitaxial layers, semiconductor lasers, semiconductor quantum wells, Applied optics. Photonics, TA1501-1820
Abstract

Abstract The authors present continuous wave (CW) high‐power broad area and ridge waveguide lasers with laser emission at 626 nm at room temperature. For this, the authors employ GaAs‐based diode lasers in the AlGaInP system for laser emission at 626 nm at room temperature. The laser structure is grown on three‐inch wafers by metal organic vapour phase epitaxy. Broad area and ridge waveguide lasers are fabricated. Pulsed broad area laser characterisation on bar level shows laser operation at 20 C heat sink temperature. The authors measured peak lasing wavelengths as short as 625 nm and total maximum output power of both facets up to 1.4 W at an injection current of 2 A. Both, broad area and ridge waveguide lasers show laser operation and CW excitation at room temperature. The ridge waveguide lasers emit output powers of over 90 mW at 626 nm at a maximum injection current of 200 mA with a nearly diffraction‐limited beam profile.

Published
2024
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5. Distributed Bragg reflector lasers emitting between 696 and 712 nm

Author

Hans Wenzel, Bassem Arar, André Maaßdorf, Jörg Fricke, Dominik Martin, Christoph Zink, Max Schiemangk, Andreas Wicht, Markus Weyers, and Andrea Knigge

Subjects
Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

Abstract The authors report on design, fabrication, and electro‐optical characterization of single‐frequency diode lasers emitting around 696, 707, and 712 nm. This has been achieved by a variation of the periods of the 10th order surface Bragg gratings implemented on a single epitaxial wafer. Depending on the wavelength, the devices achieved an optical output power of up to 60 mW at a current of 150 mA and spectral linewidths of about 400 kHz (full width at half maximum (FWHM)) and 20 kHz (Lorentzian).

Published
2022
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6. Wavelength‐stabilized ns‐pulsed 2.2 kW diode laser bar with multiple active regions and tunnel junctions

Author

Nor Ammouri, Heike Christopher, Jörg Fricke, Arnim Ginolas, Armin Liero, Andre Maaßdorf, Hans Wenzel, and Andrea Knigge

Subjects
tunnel diodes, semiconductor diodes, pulse measurement, nanoelectronics, semiconductor epitaxial layers, quantum well lasers, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

Abstract The improvement of the performance of a distributed Bragg reflector laser bar emitting near 905 nm through the use of multiple epitaxially stacked active regions and tunnel junctions is reported. The bar consisting of 48 emitters (each having an aperture of 50 µm) emits an optical power of 2.2 kW in 8 ns long pulses at an injection current of 1.1 kA. This corresponds to an almost threefold increase of the pulse power compared to a bar with lasers having only a single active region. Due to the integrated surface Bragg grating, the bar exhibits a narrow spectral bandwidth of about 0.3 nm and a thermal tuning of only 68 pm/K.

Published
2023
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7. Continuous wave operation of broad area and ridge waveguide laser diodes at 626 nm.

Author

Mauerhoff, Felix, Senel, Oktay, Wenzel, Hans, Maaßdorf, André, Boschker, Jos, Glaab, Johannes, Paschke, Katrin, and Tränkle, Günther

Subjects
QUANTUM well lasers, WAVEGUIDE lasers, METAL vapors, EPITAXIAL layers, HEAT sinks, SEMICONDUCTOR lasers
Abstract

The authors present continuous wave (CW) high‐power broad area and ridge waveguide lasers with laser emission at 626 nm at room temperature. For this, the authors employ GaAs‐based diode lasers in the AlGaInP system for laser emission at 626 nm at room temperature. The laser structure is grown on three‐inch wafers by metal organic vapour phase epitaxy. Broad area and ridge waveguide lasers are fabricated. Pulsed broad area laser characterisation on bar level shows laser operation at 20 C heat sink temperature. The authors measured peak lasing wavelengths as short as 625 nm and total maximum output power of both facets up to 1.4 W at an injection current of 2 A. Both, broad area and ridge waveguide lasers show laser operation and CW excitation at room temperature. The ridge waveguide lasers emit output powers of over 90 mW at 626 nm at a maximum injection current of 200 mA with a nearly diffraction‐limited beam profile. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Novel 1064 nm DBR lasers combining active layer removal and surface gratings

Author

O. Brox, H. Wenzel, J. Fricke, P. Della Casa, A. Maaßdorf, M. Matalla, S. Wenzel, A. Wicht, and A. Knigge

Subjects
Lasing action in semiconductors, Design of specific laser systems, Laser beam characteristics and interactions, Gratings, echelles, Laser beam interactions and properties, Semiconductor lasers, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

Abstract The fabrication and characterisation details of novel distributed Bragg reflector (DBR) diode lasers emitting around 1064 nm are presented here. The AlGaAs epitaxial layer stack used here allows the removal of the active quantum wells in passive sections where no current is injected. The DBR lasers fabricated with a two‐step epitaxial approach without an active layer in the grating sections show improved performance in terms of power, efficiency, and linewidth in comparison to its all‐active DBR counterparts.

Published
2021
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13. Novel 900 nm diode lasers with epitaxially stacked multiple active regions and tunnel junctions

Author

Hans Wenzel, Andre Maaßdorf, Christof Zink, Dominik Martin, Markus Weyers, and Andrea Knigge

Subjects
Lasing action in semiconductors, Design of specific laser systems, Laser resonators and cavities, Laser beam characteristics and interactions, Laser beam interactions and properties, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

Abstract A multi‐active‐region bipolar‐cascade edge‐emitting laser emitting at nearly 900 nm is presented. The three active regions and two tunnel junctions located in a single waveguide core share the same third‐order vertical mode. A slope efficiency of 3.6 W/A was measured with a threshold current density of 230 A/cm2. The epitaxial layer stack developed features with very low internal optical losses of 0.7 cm−1. The voltage extrapolated to vanishing current is only 0.3 V larger than 3 times the voltage of 1.4 V originating from the photon energy.

Published
2021
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15. Operational lifetime qualification of laser diodes for BECCAL

Author

Häusler, Karl, primary, Bawamia, Ahmad, additional, Boschker, Jos, additional, Baumann, Jan M., additional, Dammasch, Matthias, additional, Wenzel, Hans, additional, Knigge, Andrea, additional, Fricke, Jörg, additional, Maaßdorf, Andre, additional, and Wicht, Andreas, additional

Published
2023
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18. Design Strategies to Optimize 660 nm DBR Tapered Laser Performance

Author

Blume, Gunnar, primary, Matalla, Oliver, additional, Wenzel, Hans, additional, Maaßdorf, André, additional, Feise, David, additional, Fricke, Jörg, additional, Ressel, Peter, additional, Kreutzmann, Sabrina, additional, Ginolas, Arnim, additional, Sahm, Alexander, additional, Knigge, Andrea, additional, and Paschke, Katrin, additional

Published
2023
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24. Single mode 660 nm DBR tapered laser with 1 W optical output power

Author

Blume, Gunnar, primary, Matalla, Oliver, additional, Wenzel, Hans, additional, Maassdorf, Andre, additional, Feise, David, additional, Fricke, Jörg, additional, Ressel, Peter, additional, Kreutzmann, Sabrina, additional, Ginolas, Arnim, additional, Sahm, Alexander, additional, Knigge, Andrea, additional, and Paschke, Katrin, additional

Published
2023
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27. Experimental Studies Into the Beam Parameter Product of GaAs High-Power Diode Lasers

Author

Günther Tränkle, Paul Crump, Mohamed Elattar, Stephan Strohmaier, Stewart McDougall, Stefan Gruetzner, Andre Maaßdorf, Simon Rauch, Carlo Holly, Dominik Martin, Md. Jarez Miah, Michael Ekterai, and Matthias M. Karow

Subjects
Diffraction, Materials science, business.industry, Optical field, Laser, Beam parameter product, Atomic and Molecular Physics, and Optics, law.invention, Semiconductor laser theory, Lens (optics), law, Optoelectronics, Electrical and Electronic Engineering, business, Refractive index, Diode
Abstract

Experimental studies into the beam parameter product ( BPP ) of 940–980 nm GaAs-based high-power diode lasers are presented. Such lasers exhibit broadening far field and narrowing near field with increasing bias, with BPP increasing tenfold over the diffraction limit. First, spectrally-resolved beam profile measurements of lasers with monolithically-integrated gratings are presented, showing that a reproducible series of spatially-extended optical modes makes up the optical field. Then, changes to the device construction are presented, enabling effects limiting BPP to be inferred and addressed. Process- and package-induced effects can be minimized by design, while the effects of carrier, gain and temperature profiles dominate. Self-heating within the laser stripe raises the refractive index, forming a thermal lens, and the variation in curvature of this lens with bias and device construction directly affects BPP . Temperature non-uniformity along the resonator is also shown to strongly degrade BPP . Moreover, current spreading and the resulting lateral carrier accumulation (LCA) amplify high-order, high- BPP modes, thus degrading BPP for any given thermal lens. This LCA-induced degradation is shown to be suppressed by regrown lateral current-blocking structures. Finally, a flatter thermal lens and lower BPP can be achieved using thermal engineering, via changes to the epitaxial design or device layout.

Published
2022
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31. Wavelength-stabilized ns-pulsed 2.2 kW diode laser bar with multiple active regions and tunnel junctions

Author

Nor Ammouri, Heike Christopher, Jörg Fricke, Arnim Ginolas, Armin Liero, Andre Maassdorf, Hans Wenzel, and Andrea Knigge

Abstract

The improvement of the performance of a distributed Bragg reflector laser bar emitting near 905 nm through the use of multiple epitaxially stacked active regions and tunnel junctions is reported. The bar consisting of 48 emitters (each having an aperture of 50 μm) emits an optical power of 2.2 kW in 8 ns long pulses at an injection current of 1.1 kA. This corresponds to an almost threefold increase of the pulse power compared to a bar with lasers having only a single active region. Due to the integrated surface Bragg grating, the bar exhibits a narrow spectral bandwidth of about 0.3 nm and a thermal tuning of only 68 pm/K.

Published
2022
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43. Novel 1064 nm DBR lasers combining active layer removal and surface gratings

Author

Olaf Brox, S. Wenzel, Andrea Knigge, Andre Maaßdorf, P. Della Casa, M. Matalla, Andreas Wicht, Hans Wenzel, and J. Fricke

Subjects
Surface (mathematics), Materials science, law, business.industry, Optoelectronics, Electrical engineering. Electronics. Nuclear engineering, Electrical and Electronic Engineering, Laser, business, law.invention, Active layer, TK1-9971
Abstract

The fabrication and characterisation details of novel distributed Bragg reflector (DBR) diode lasers emitting around 1064 nm are presented here. The AlGaAs epitaxial layer stack used here allows the removal of the active quantum wells in passive sections where no current is injected. The DBR lasers fabricated with a two‐step epitaxial approach without an active layer in the grating sections show improved performance in terms of power, efficiency, and linewidth in comparison to its all‐active DBR counterparts.

Published
2021

48. Longitudinal spatial hole burning and associated non-uniform current and carrier density profile as a power limit in high power diode lasers

Author

Arslan, Seval, primary, Wenzel, Hans, additional, Fricke, Jörg, additional, Thies, Andreas, additional, Ginolas, Arnim, additional, Stölmacker, Christoph, additional, Maassdorf, Andre, additional, Eppich, Bernd, additional, Swertfeger, Rebecca B., additional, Patra, Susant K., additional, Deri, Robert J., additional, Boiselle, Matthew C., additional, Pope, David L., additional, Leisher, Paul O., additional, Tränkle, Günther, additional, and Crump, Paul A., additional

Published
2022
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49. Progress in experimental studies into the beam parameter product of GaAs-based high-power diode lasers

Author

Crump, Paul A., primary, Elattar, Mohamed, additional, Miah, Mohammad Jarez, additional, Ekterai, Michael, additional, Karow, Matthias M., additional, Martin, Dominik, additional, Della Casa, Pietro, additional, Maassdorf, Andre, additional, McDougall, Stewart, additional, Holly, Carlo, additional, Rauch, Simon, additional, Gruetzner, Stefan, additional, Strohmaier, Stephan G., additional, Knigge, Andrea, additional, and Tränkle, Günther, additional

Published
2022
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50. Distributed Bragg Reflector Lasers at 689.45 nm for Sr Spectroscopy

Author

Nora Goossen-Schmidt, Christoph Pyrlik, Muhammad Tehwar Hassan, Ahmad Bawamia, Jörg Fricke, Andrea Knigge, Andre Maaßdorf, Max Schiemangk, Hans Wenzel, and Andreas Wicht

Abstract

We present distributed Bragg reflector lasers optimized for strontium-based quantum technology applications at 689.449 nm. The devices achieved optical output powers up to 88 mW, four times more than previously reported, and a spectral linewidth of 0.4MHz.

Published
2022
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