Abstract
A transparent Tm:Lu3Al5O12 ceramic is fabricated by solid-state reactive sintering at 1830°C for 30 h using commercial α-Al2O3 and Lu2O3/Tm2O3 powders and sintering aids - MgO and TEOS. The ceramic belongs to the cubic system and exhibits a close-packed structure (mean grain size: 21 μm). The in-line transmission at ∼1 μm is 82.6%, close to the theoretical limit. The spectroscopic properties of the ceramic are studied in detail. The maximum stimulated-emission cross-section is 2.37x10-21 cm2 at 1749nm and the radiative lifetime of the 3F4 state is about 10 ms. The modified Judd-Ofelt theory accounting for configuration interaction is applied to determine the transition probabilities of Tm3+, yielding the intensity parameters 2 = 2.507, 4 = 1.236, 6 = 1.340 [10-20 cm2] and α = 0.196x10-4 cm. The effect of excited configurations on lower-lying interconnected states with the same J quantum number is discussed. First laser operation is achieved under diode-pumping at 792 nm. A 4 at.% Tm:Lu3Al5O12 ceramic laser generated 3.12 W at 2022-2035nm with a slope efficiency of 60.2%. The ceramic is promising for multi-watt lasers at >2 μm.
Original language | English |
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Pages (from-to) | 28399-28413 |
Number of pages | 15 |
Journal | Optics Express |
Volume | 28 |
Issue number | 19 |
DOIs | |
State | Published - Sep 2020 |
Externally published | Yes |
Funding
Ministerio de Economía y Competitividad (MAT2016-75716-C2-1-R (AEI/FEDER, UE)); Agència de Gestió d’Ajuts Universitaris i de Recerca (2017SGR755); Horizon 2020 Framework Programme (grant agreement No. 739573); European Regional Development Fund (Grant No. CZ.02.1.01/0.0/0.0/15_006/0000674); Ministerstvo Školství, Mládeže a Tělovýchovy (Large Research Infras. Project No. LM2015086, NPU I Project No. LO1602); Chinese Academy of Sciences Key Project (QYZDB-SSW-JSC022).