Time-Dependent Simulation of Thermal Lensing in High-Power Broad-Area Semiconductor Lasers

A. Zeghuzi1, H.-J. Wünsche1,2, H. Wenzel1, M. Radziunas2, J. Fuhrmann2, A. Klehr1, U. Bandelow2, and A. Knigge1

Published in:

IEEE J. Sel. Top. Quantum Electron., vol. 25, no. 6, pp. 1502310 (2019).

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Abstract:

We propose a physically realistic and yet numerically applicable thermal model to account for short- and long-term self-heating within broad-area lasers. Although the temperature increase is small under pulsed operation, a waveguide that is formed within a few-nanosecond-long pulse can result in a transition from a gain-guided to an index-guided structure, leading to near and far field narrowing. Under continuous wave operation, the longitudinally varying temperature profile is obtained self-consistently. The resulting unfavorable narrowing of the near field can be successfully counteracted by etching trenches.

1 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
2 Weierstrass Institute for Applied Analysis and Stochastics, 10117 Berlin, Germany

Index Terms:

Broad-area laser, heat flow, pulsed laser operation, traveling-wave model, thermal lensing, temperature fluctuation.