Dr. Volker K. Härle Profile

Dr. Volker K. Härle

at ams-OSRAM International GmbH

SPIE Involvement:

Author

Proceedings Article | 23 March 2007 Paper

Analysis of substrate modes in GaN/InGaN lasers

Bernd Witzigmann, Valerio Laino, Friedhard Roemer, Christoph Lauterbach, Ulrich Schwarz, Christian Rumbolz, Martin Schillgalies, Alfred Lell, Uwe Strauss, Volker Härle

Proceedings Volume 6468, 64680Q (2007) https://doi.org/10.1117/12.700920

KEYWORDS: Waveguides, Near field optics, Optical simulations, Dispersion, Refractive index, Semiconductor lasers, Gallium nitride, Waveguide modes, Metals, Semiconductors

Read Abstract +

Proceedings Article | 8 February 2007 Paper

Degradation studies of InGaN/GaN heterostructure laser diodes using a Kelvin Force Microscope

André Lochthofen, Wolfgang Mertin, Gerd Bacher, Michael Furitsch, Georg Brüderl, Berthold Hahn, Uwe Strauss, Volker Härle

Proceedings Volume 6473, 64730Z (2007) https://doi.org/10.1117/12.704855

KEYWORDS: Diodes, Semiconductor lasers, Microscopy, Heterojunctions, Gallium nitride, Mirrors, Electroluminescence, Gold, Silicon carbide, Magnesium

Read Abstract +

Proceedings Article | 14 April 2006 Paper

Time-resolved scanning near-field microscopy of InGaN laser diode dynamics

U. Schwarz, C. Lauterbach, M. Schillgalies, C. Rumbolz, M. Furitsch, A. Lell, V. Härle

Proceedings Volume 6184, 61840K (2006) https://doi.org/10.1117/12.662019

KEYWORDS: Near field scanning optical microscopy, Semiconductor lasers, Indium gallium nitride, Near field, Waveguides, Etching, Oscilloscopes, Waveguide modes, Microscopy, Quantum wells

Read Abstract +

Proceedings Article | 20 October 2004 Paper

Study of short-term instabilities of InGaN/GaN light-emitting diodes by means of capacitance-voltage measurements and deep-level transient spectroscopy

Gaudenzio Meneghesso, Matteo Meneghini, Simone Levada, Enrico Zanoni, Anna Cavallini, Antonio Castaldini, Volker Harle, Thomas Zahner, Ulrich Zehnder

Proceedings Volume 5530, (2004) https://doi.org/10.1117/12.566159

KEYWORDS: Light emitting diodes, Capacitance, Doping, Electroluminescence, Temperature metrology, Spectroscopy, Quantum wells, Spectroscopes, Gallium nitride, Optical testing

Read Abstract +

Proceedings Article | 11 May 2004 Paper

Nitride-based in-plane laser diodes with vertical currrent path

Ulrich Schwarz, Werner Wegscheider, Alfred Lell, Volker Haerle

Proceedings Volume 5365, (2004) https://doi.org/10.1117/12.529087

KEYWORDS: Silicon carbide, Modulation, Semiconductor lasers, Waveguide modes, Gallium nitride, Waveguides, Mirrors, Nitrogen, Sapphire, Etching

Read Abstract +

Proceedings Article | 26 January 2004 Paper

Advanced technologies for high-efficiency GaInN LEDs for solid state lighting

Volker Harle, Berthold Hahn, Johannes Baur, Michael Fehrer, Andreas Weimar, Stephan Kaiser, Dominik Eisert, Franz Eberhard, Andreas Plossl, Stefan Bader

Proceedings Volume 5187, (2004) https://doi.org/10.1117/12.521358

KEYWORDS: Light emitting diodes, Silicon carbide, Sapphire, Photons, Solid state lighting, Reflectivity, Standards development, Gallium nitride, Gallium arsenide, Indium gallium nitride

Read Abstract +

Proceedings Article | 3 July 2003 Paper

Light extraction technologies for high efficiency GaInN-LED devices

Volker Haerle, Berthold Hahn, Stephan Kaiser, Andreas Weimar, Dominik Eisert, Stefan Bader, Andreas Ploessl, Franz Eberhard

Proceedings Volume 4996, (2003) https://doi.org/10.1117/12.476591

KEYWORDS: Light emitting diodes, Quantum wells, Manufacturing, RGB color model, Laser liftoff, Sapphire, Gallium arsenide, Reflectivity

Read Abstract +

Proceedings Article | 19 June 1995 Paper

Optoelectronic nanostructures: physics and technology

Heinz Schweizer, Uwe Griesinger, Volker Haerle, Frank Adler, Manfred Burkard, Frank Barth, Juergen Hommel, Christiane Kaden, Janos Kovac, Justus Kuhn, Bernd Klepser, Georg Lehr, Freek Prins, Ferdinand Scholz, Manfred Pilkuhn, Josef Straka, Alfred Forchel, Gilbert Smith

Proceedings Volume 2399, (1995) https://doi.org/10.1117/12.212517

KEYWORDS: Laser damage threshold, Etching, Photomasks, Nanostructures, Semiconductors, Laser resonators, Quantum efficiency, Resonators, Ions, Dry etching

Read Abstract +

Nanostructures based on III-V semiconductor materials have reached a status which enables basic physical studies on size effects in device and in nanostructures. The expected benefits of high modulation bandwidth, low laser threshold, and improved linewidth enhancement factor in DFB lasers, to say only a few, which are believed to be based mainly on the changed density of states (DOS) function in low dimensions might be counterbalanced by altered carrier energy relaxation and k-space filling in those structures. To investigate systematically size effects and device aspects, a continuous change of structure and active device size is needed from 2D to 0D dimensions. This requirement can be met by high resolution electron beam lithography in conjunction with low damage etch processes and epitaxial overgrowth. In this presentation we discuss the technology and design considerations of lasers with low dimensional active regions as well as DOS effects and device relevant carrier relaxation effects. The technology part will focus especially on low damage etch processes such as RIE- ECR. Nearly damage free structuring processes can be demonstrated. Based on this low damage dry etch process we obtained electrically pumped wire DFB lasers with relatively high output power (up to 6 mW) and operation temperature (60 degrees C). Time resolved optical ps-spectroscopy as well as high excitation spectroscopy on wire and dot nanostructures demonstrate strongly changed k-space filling and carrier relaxation mechanisms in low dimensions and represent a serious limitation of device speed. Results obtained from electrically pumped wire DFB lasers confirm the carrier relaxation and k-space filling effects in device structures which have been observed by optical pump experiments in nanostructures. Despite the band filling effects in low dimensional structures, the wire DFB lasers show clearly the expected feature of gain coupling and enhanced differential gain which might demonstrate the applicability of mesoscopic laser devices in common data communication approaches.

Showing 5 of 8 publications

Conference Committee Involvement (10)

Twelfth International Conference on Solid State Lighting and Fourth International Conference on White LEDs and Solid State Lighting

13 August 2012 | San Diego, California, United States

Eleventh International Conference on Solid State Lighting

22 August 2011 | San Diego, California, United States

Tenth International Conference on Solid State Lighting

2 August 2010 | San Diego, California, United States

Ninth International Conference on Solid State Lighting

3 August 2009 | San Diego, California, United States

Eighth International Conference on Solid State Lighting

11 August 2008 | San Diego, California, United States

Showing 5 of 10 Conference Committees

Keywords/Phrases

Search In:

Publication Years