Optical microprism cavities based on dislocation-free GaN
Journal article, 2020

Three-dimensional growth of nanostructures can be used to reduce the threading dislocation density that degrades III-nitride laser performance. Here, nanowire-based hexagonal GaN microprisms with flat top and bottom c-facets are embedded between two dielectric distributed Bragg reflectors to create dislocation-free vertical optical cavities. The cavities are electron beam pumped, and the quality (Q) factor is deduced from the cavity-filtered yellow luminescence. The Q factor is similar to 500 for a 1000nm wide prism cavity and only similar to 60 for a 600nm wide cavity, showing the strong decrease in Q factor when diffraction losses become dominant. Measured Q factors are in good agreement with those obtained from quasi-3D finite element frequency-domain method and 3D beam propagation method simulations. Simulations further predict that a prism cavity with a 1000nm width will have a Q factor of around 2000 in the blue spectral regime, which would be the target regime for real devices. These results demonstrate the potential of GaN prisms as a scalable platform for realizing small footprint lasers with low threshold currents.


Filip Hjort

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Maryam Khalilian

Lund University

Jörgen Bengtsson

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Marcus Bengths

Student at Chalmers

Johan Gustavsson

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Anders Gustafsson

Lund University

Lars Samuelson

Lund University

Åsa Haglund

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Applied Physics Letters

0003-6951 (ISSN) 1077-3118 (eISSN)

Vol. 117 23 231107

Subject Categories

Accelerator Physics and Instrumentation

Atom and Molecular Physics and Optics

Other Physics Topics



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