Abstract
Using high power quasi-cw pulse pumping, we show that energy transfer upconversion (ETU) processes in highly doped Dy3+ double clad ZBLAN fibers creates a pathway for significant excitation loss that clamps the gain. For a 4 mol.% Dy3+-doped fiber, we establish that the pump absorption is non-saturable up to a maximum launched (peak) pump power of 100 W. We propose that this arises from a co-operative three-ion ETU process. Additionally, the high power pulsed pumping of Tm3+, Dy3+-co-doped fiber produces laser relaxation spikes that appear after the pump pulse, suggesting that ETU dominates all other process during pumping.
Original language | English |
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Pages (from-to) | 2591-2597 |
Number of pages | 7 |
Journal | OSA Continuum |
Volume | 4 |
Issue number | 10 |
DOIs | |
Publication status | Published - 15 Oct 2021 |