Close look on cubic Tm:KY 3 F 10 crystal for highly efficient lasing on the 3 H 4 → 3 H 5 transition

Lauren Guillemot (1) , Pavel Loiko (1) , Rémi Soulard (1, 2) , Alain Braud (1) , Jean-Louis Doualan (1) , Ammar Hideur (3) , Patrice Camy (1)

1 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique
2 ARTEMIS - Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux
3 CORIA - Complexe de recherche interprofessionnel en aérothermochimie

We report on Czochralski growth, detailed ground- and excited-state absorption and emission spectroscopy and highly-efficient mid-infrared (∼2.3 µm) laser operation of a cubic potassium yttrium fluoride crystal, Tm:KY3F10. The peak stimulated-emission cross-section for the 3H4 → 3H5 transition is 0.34×10−20 cm2 at 2345 nm with an emission bandwidth exceeding 50 nm. The excited-state absorption spectra for the 3F4 → 3F2,3 and 3F4 → 3H4 transitions are measured and the cross-relaxation is quantified. A continuous-wave 5 at.% Tm:KY3F10 laser generated 0.84 W at 2331-2346 nm by pumping at 773 nm, with a record-high slope efficiency of 47.7% (versus the incident pump power) owing to the efficient action of energy-transfer upconversion leading to a pump quantum efficiency approaching 2. The first Tm:KY3F10 laser with ESA-assisted upconversion pumping (at 1048 nm) is also demonstrated. Due to its broadband emission properties, Tm:KY3F10 is promising for ultrashort pulse generation at ∼2.3-2.4 µm.

Domaines: Optique / photonique

Lauren Guillemot, Pavel Loiko, Rémi Soulard, Alain Braud, Jean-Louis Doualan, et al.. Close look on cubic Tm:KY 3 F 10 crystal for highly efficient lasing on the 3 H 4 → 3 H 5 transition. Optics Express, 2020, 28 (3), pp.3451. ⟨10.1364/OE.382650⟩. ⟨hal-02747031⟩