Regensburg 2025 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 39: Poster III

HL 39.21: Poster

Wednesday, March 19, 2025, 15:00–18:00, P3

Impact of stress current on reverse-bias electroluminescence images of 850 nm oxide-confined VCSELs — •Arndt Jaeger¹, Nikolay Ledentsov Jr.², Sebastian Haberkern¹, Helmut Meinert¹, Alexander Moll¹, Ilya E. Titkov², Oleg Yu. Makarov², and Nikolay N. Ledentsov² — ¹Esslingen University of Applied Sciences, Flandernstrasse 101, 73732 Esslingen, Germany — ²VI Systems GmbH, Hardenbergstrasse 7, 10623 Berlin, Germany

Vertical-cavity surface-emitting lasers (VCSEL) employing different doping of the cavity region are studied utilizing reverse current-voltage (IV) characteristics as well as reverse bias electroluminescence (ReBEL). Reverse IV characteristics exhibits avalanche breakdown enabling an estimation of the electric field in the cavity region. ReBEL emission is observed at locations where avalanche breakthrough current has its maximum. The oxide-confined VCSELs are characterised before and after high current operation. Virgin devices have a homogeneous device center in ReBEL images. Upon a short high current burn-in VCSELs evolved a homogeneous ring at the oxide-aperture perimeter. This ring structure decays into 2 point-like areas after long-term current stress. These observations in ReBEL images can be understood in terms of recently published VCSEL simulation results which gave evidence of local current crowding at the oxide-aperture during high current laser operation.

Keywords: vertical-cavity surface-emitting laser; reverse bias electroluminescence; degradation