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Single-frequency 100 ns / 0.5 mJ laser pulses from all-fiber double clad ytterbium doped tapered fiber amplifier

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Pages (from-to)31532-31541
Number of pages10
JournalOptics Express
Issue number22
Publication statusPublished - 28 Oct 2019
Publication typeA1 Journal article-refereed


High peak power, narrow linewidth sources continue to be in high demand. Fiber amplifiers are a compelling option to scale peak power of long 100-ns-pulses because of their compact size and robustness. Unfortunately, stimulated Brillouin scattering (SBS) limits peak power of narrow linewidth fiber sources causing instability. We demonstrate SBS suppression for 130-ns pulses from a 5 MHz linewidth seed laser in a fiber amplifier by using tapered fiber with large 50 mu m diameter core in the output. The longitudinal change in the core diameter induces frequency shift in the SBS gain peak and the back-travelling Stokes wave is suppressed towards smaller core. We reach 2.2 kW peak power with 18.7 dB polarization extinction ratio and record breaking 4 kW peak power by exciting both polarization states of the polarization maintaining tapered fiber. The output beam quality equals to single mode fibers with M-2 = 1.08. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement



Publication forum classification

Field of science, Statistics Finland