940nm Broad Area Diode Lasers Optimized for High Pulse-Power Fiber Coupled Applications

R. Platz, B. Eppich, P. Crump, W. Pittroff, S. Knigge, A. Maaßdorf and G. Erbert

Published in:

IEEE Photonics Technol. Lett., vol. 26, no. 6, pp. 625-628 (2014).

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Abstract:

Diode lasers with 400 µm stripe widths measured in pulsed-current mode are shown to reach peak (saturation) powers of 60 W for 1 ms pulses (60 mJ) and 189 W for 300 ns pulses (∼55 µJ). Use of a laterally structured contact and etched index guides at the stripe edges enables these devices to sustain stable lateral near- and far-field profiles to the highest bias, with a lateral beam parameter product of < 30 mm.mrad. Optical calculations are presented for an example system where arrays of these single emitters are incoherently coupled into a fiber with 1mm core and numerical aperture of 0.22, extrapolating 5 kW in fiber for 1 ms (5 J) and 18 kW in-fiber for 300 ns pulses (∼5 mJ). Such sources would be well suited for pumping Yb:YAG crystals for applications needing high beam quality, or as direct sources.

Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany

Index Terms:

diode laser, pulsed source, fiber coupling, lateral structure, high power.