Highly Efficient High-Brightness 970nm Ridge Waveguide Lasers

M. Wilkens, G. Erbert, H. Wenzel, A. Maaßdorf, J. Fricke, P. Ressel, A. Knigge, and P. Crump

Published in:

IEEE Photonics Technol. Lett., vol. 32, no. 7, pp. 406-409 (2020).

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Abstract:

In this letter we present new results on high power 970 nm ridge waveguide lasers based on an extreme double asymmetric epitaxial design. Due to an improved lateral-longitudinal design an M2-value below 1.1 and efficiency over 60% could be maintained at power levels slightly above 2 W. The lasers consist of a narrow mode-filter section at the back facet, a relatively broad section at the front facet for high power capability, and a tapered section in between with a very small taper-angle. We achieved the highest reported conversion efficiency for 1 W single lateral mode power to date of 67%, as well as the highest lateral (linear) brightness of 7.5 W/mm·mrad with 55% efficiency at 2.5 W. Results of first life time tests are presented which show the potential for commercial use.

Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany

Index Terms:

Diode lasers, high brightness, high efficiency, ridge waveguides, adiabatic taper.