Zobrazeno 1 - 10
of 44
pro vyhledávání: '"Karlheinz H. Gulden"'
Publikováno v:
Journal of Applied Physics. 91:2563-2568
Detailed study of external quantum efficiency ηQE is reported for AlGaInP-based microcavity light-emitting diodes (MCLEDs). Unlike conventional light-emitting diodes (LEDs) the extraction efficiency γext and far field profile depend on the linewidt
Autor:
A.R. Boyd, S.J. Fancey, M. G. Forbes, Andrew C. Walker, Paul Horan, Sven Eitel, Jean-Louis Gutzwiller, Mohammad R. Taghizadeh, John Hegarty, D. Byrne, Karlheinz H. Gulden, J.A.B. Dines, Philippe Benabes, A. Gauthier, Gerald S. Buller, Marc P.Y. Desmulliez, C.R. Stanley, H.-P. Gauggel, Giovanni Pennelli, M. Goetz
Publikováno v:
IEEE Journal of Selected Topics in Quantum Electronics. 5:236-249
The completed detailed design and initial phases of construction of an optoelectronic crossbar demonstrator are presented. The experimental system uses hybrid very large scale integrated optoelectronics technology whereby InGaAs-based detectors and m
Publikováno v:
Journal of Crystal Growth. 170:404-407
Top-emitting Alas AlGaAs vertical cavity surface emitting lasers emitting at 765 nm with minimum threshold currents of 0.6 mA and threshold voltages of 1.9 V have been grown by MOVPE. In order to keep the growth time low, we investigated the possibil
Autor:
Merlin Thomas, John R. Whinnery, G. C. Wilson, X. Wu, Karlheinz H. Gulden, J. Walker, John Smith, Gottfried H. Döhler
Publikováno v:
Journal of Crystal Growth. 127:896-899
We present the shadow mask MBE regrowth technique, with which we are able to grow 3D structures, size ranging from several to hundreds of μm, that enable vs to directly contact quantum structures as thin as 10 nm and to make interdigitated contacts.
Autor:
N. Linder, P. Riel, X. Wu, Peter Kiesel, John Smith, B. Knupfer, Karlheinz H. Gulden, A. Höfler, G. H. Döhler, Michael Kneissl
Publikováno v:
Superlattices and Microstructures. 13:21-24
We report on electro-optical modulators with high contrast ratio. The on/off ratio of a homogenous GaAs n-i-p-i structure only 3.9μm thick is larger than 6:1, without additional cavity effects for a voltage swing of only 7V. This change of the refle
Autor:
Peter Kiesel, Norbert Linder, Karlheinz H. Gulden, Michael Kneissl, A. Höfler, X. Wu, Gottfried H. Döhler, John Smith, Stefan Malzer
Publikováno v:
physica status solidi (b). 173:459-472
Optical nonlinearities in n-i-p-i and hetero-n-i-p-i structures with selective ohmic contacts, are reported. In this kind of structures strong changes of the absorption and refractive index are achieved either by field effects and/or with phase space
Publikováno v:
Applied Physics Letters. 77:3899-3901
A simple method for determining the intrinsic spontaneous spectrum of vertical-cavity surface-emitting devices is presented. The procedure is based on angle-resolved measurements of the top-emission spectra and comparison with numerical simulations,
Autor:
Mohammad R. Taghizadeh, Sven Eitel, S.J. Fancey, Karlheinz H. Gulden, W. Bachtold, H.-P. Gauggel
Publikováno v:
IEEE Photonics Technology Letters. 12:459-461
In this paper, work is described on the fabrication of highly uniform 8/spl times/8 arrays of GaAs-AlGaAs vertical-cavity surface-emitting lasers (VCSEL's). Oxide-confined VCSEL arrays show an average threshold current of 0.74/spl plusmn/0.02 mA, an
Publikováno v:
Applied Physics Letters. 76:7-9
The thickness and position of an oxide layer inside a vertical-cavity surface-emitting laser structure have been optimized for minimum optical scattering loss. In the resulting structure, the index guiding provided by the oxide aperture is very small
Autor:
R. Hovel, M. Ilegems, Romuald Houdré, P. Royo, H.P. Schweizer, R. P. Stanley, M. Moser, Karlheinz H. Gulden
Publikováno v:
Applied Physics Letters. 75:4052-4054
We present results on visible red top-emission microcavity light-emitting diodes grown by metal organic chemical vapor deposition. The emission characteristics dependence with respect to the detuning between the quantum well emission and the cavity m