Dy3+:Lu2O3 as a novel crystalline oxide for mid-infrared laser applications

We investigate the cubic sesquioxide Dy3+:Lu2O3 as a gain material for lasers in the mid-infrared spectral range. Bulk crystals of this material have been grown from the melt for the first time in the course of our experiments. Spectroscopic characterizations of the material show that it compares very favorably with more established materials like Dy3+:ZBLAN. The energetic positions of the energy levels up to 14,000 cm−1 were identified by spectroscopy at 11 K. Additionally, absorption cross-sections as high as 2.2 × 10−20 cm2 at 1.26 µm, and emission cross-sections as high as 6.7 × 10−21 cm2 at 2.777 µm, were determined. Furthermore, the room temperature fluorescence lifetime of the 6H13/2 multiplet was determined as 50 µs, which points to serious quenching as compared to the estimated radiative lifetime in the order of 20 ms.