Excited-state absorption of Tm$^{3+}$ ions in cubic sesquioxides

Abstract

International audienceExcited-state absorption of Tm$^{3+}$ ions in R$_2$O$_3$ (R = Y, Lu, Sc) cubic sesquioxides was studied by the pump-probe method focusing on the $^3$F$_4$ → $^3$F$_{2,3}$ (at ~1 μm) and 3F4 → 3H4 (at ~1.45 μm) transitions. The energy-transfer upconversion is also quantified in these materials. The performed studies are essential for the design of 2.3 μm Tm lasers