Open AccessSingle mode 43 kW output power from a diode-pumped Yb-doped fiber amplifier
Author(s) -
Franz Beier,
Christian Hupel,
Stefan Kühn,
Sigrun Hein,
Johannes Nold,
Fritz Proske,
Bettina Sattler,
A. Liem,
César Jáuregui,
Jens Limpert,
Nicoletta Haarlammert,
Sabu Thomas,
Ramona Eberhardt,
Andreas Tünnermann
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.014892
Subject(s) - laser linewidth , optics , materials science , brillouin scattering , fiber laser , amplifier , double clad fiber , laser beam quality , slope efficiency , optoelectronics , laser , optical fiber , polarization maintaining optical fiber , fiber optic sensor , physics , laser beams , cmos
We investigate the average power scaling of two diode-pumped Yb-doped fiber amplifiers emitting a diffraction-limited beam. The first fiber under investigation with a core diameter of 30 µm was able to amplify a 10 W narrow linewidth seed laser up to 2.8 kW average output power before the onset of transverse mode instabilities (TMI). A further power scaling was achieved using a second fiber with a smaller core size (23µm), which allowed for a narrow linewidth output power of 3.5 kW limited by stimulated Brillouin scattering (SBS). We mitigated SBS using a spectral broadening mechanism, which allowed us to further increase the output power to 4.3 kW only limited by the available pump power. Up to this power level, a high slope efficiency of 90% with diffraction-limited beam quality and without any sign of TMI or stimulated Raman scattering for a spectral dynamic range of higher than -80 dB was obtained.