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Mode-locked Cr:LiSAF laser far off the gain peak: tunable sub-200-fs pulses near 1 µm

U. Demirbas1,2, J. Thesinga1, M. Kellert1, S. Reuter1, B. Sumpf3, M. Pergament1, and F.X. Kartner1,4,5

Published in:

Appl. Opt., vol. 60, no. 29, pp. 9054-9061, doi:10.1364/AO.440263 (2021).


We report, to the best of our knowledge, the first mode-locking results of a Cr:LiSAF laser near the 1 µmregion. The system is pumped only by a single 1.1 W high-brightness tapered diode laser at 675 nm. A semiconductor saturable absorber mirror (SESAM) with a modulation depth of 1.5% and non-saturable losses below 0.5% was used for mode-locking. Once mode-locked, the Cr:LiSAF laser produced almost-transform-limited sub-200-fs pulses with up to 12.5 mW of average power at a repetition rate of 150 MHz.Using an intracavity birefringent filter, the central wavelength of the pulses could be smoothly tuned in the 1000-1020 nm range. Via careful dispersion optimization, pulse widths could be reduced down to the 110-fs level. The performance in this initial study was limited by the design parameters of the SESAM used, especially its passive losses and could be improved with an optimized SESAM design.

1 Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
2 Laser Technology Laboratory, Department of Electrical and Electronics Engineering, Antalya Bilim University, 07190 Dosemealti, Antalya, Turkey
3 Ferdinand-Braun-Institut gGmbH, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany
4 Physics Department, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
5 The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany


Diode lasers, High power lasers, Laser efficiency, Laser operation, Reverse saturable absorbers, Solid state lasers

© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

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