Low-Threshold AlGaN-based UVB VCSELs enabled by post-growth cavity detuning
Journal article, 2022
The performance of vertical-cavity surface-emitting lasers (VCSELs) is strongly dependent on the spectral detuning between the gain peak and the resonance wavelength. Here, we use angle-resolved photoluminescence spectroscopy to investigate the emission properties of AlGaN-based VCSELs emitting in the ultraviolet-B spectral range with different detuning between the photoluminescence peak of the quantum-wells and the resonance wavelength. Accurate setting of the cavity length, and thereby the resonance wavelength, is accomplished by using doping-selective electrochemical etching of AlGaN sacrificial layers for substrate removal combined with deposition of dielectric spacer layers. By matching the resonance wavelength to the quantum-wells photoluminescence peak, a threshold power density of 0.4 MW/cm2 was achieved, and this was possible only for smooth etched surfaces with a root mean square roughness below 2 nm. These results demonstrate the importance of accurate cavity length control and surface smoothness to achieve low-Threshold AlGaN-based ultraviolet VCSELs.
Author
G. Cardinali
Technische Universität Berlin
Filip Hjort
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
N. Prokop
Technische Universität Berlin
Johannes Enslin
Technische Universität Berlin
Munise Cobet
Technische Universität Berlin
Michael Alexander Bergmann
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Johan Gustavsson
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Joachim Ciers
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Ines Häusler
Technische Universität Berlin
Tim Kolbe
Ferdinand-Braun-Institut fur Hochstfrequenztechnik
Tim Wernicke
Technische Universität Berlin
Åsa Haglund
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Michael Kneissl
Ferdinand-Braun-Institut fur Hochstfrequenztechnik
Technische Universität Berlin
Applied Physics Letters
0003-6951 (ISSN) 1077-3118 (eISSN)
Vol. 121 10 103501Ultravioletta och blå mikrokavitetslasrar
Swedish Research Council (VR) (2018-00295), 2019-01-01 -- 2024-12-31.
Subject Categories
Atom and Molecular Physics and Optics
Other Physics Topics
Condensed Matter Physics
DOI
10.1063/5.0097903