Continuous-wave operation of DFB laser diodes based on GaN using 10th-order laterally coupled surface gratings

Y.H. Kang1, E. Freier1, V. Hoffmann1, O. Brox1, J. Fricke1, L. Sulmoni2, M. Matalla1, C. Stölmacker1, M. Kneissl1,2, M. Weyers1, and S. Einfeldt1

Published in:

Opt. Lett., vol. 45, no. 4, pp. 935-938 (2020).

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Abstract:

Single longitudinal mode continuous-wave operation of distributed-feedback (DFB) laser diodes based on GaN is demonstrated using laterally coupled 10th-order surface Bragg gratings. The gratings consist of V-shaped grooves alongside a 1.5 µm wide p-contact stripe fabricated by using electron-beam lithography and plasma etching. By varying the period of the Bragg grating, the lasing wavelength could be adjusted between 404.8 and 408.5 nm. The feasibility of this device concept was confirmed by mode-hop-free operation up to an optical output power of 90 mW, a low temperature sensitivity of the lasing wavelength, and a Gaussian lateral farfield distribution.

1 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
2 Institute of Solid State Physics, Technische Universität Berlin, 10623 Berlin, Germany