2 μm Ultrabroad spectra and laser operation of Tm:GdScO3 crystal

Abstract Spectra and laser operation at 2 μm of Tm:GdScO3 crystal are investigated for the first time. The low symmetry in GdScO3 crystal broadens emission spectrum (269 nm) of Tm3+:3F4 → 3H6 transition, which is the widest in Tm3+ doped crystals. The emission cross-sections at 1975 nm are approximately 0.23 (E//X), 0.23 (E//Y) and 0.28 (E//Z) × 10-20 cm2, respectively. The fluorescence lifetime of Tm3+:3F4 is 3.68 ms. Pumped by a 793 nm laser diode, the output power yields 4.53 W with the slope efficiency of 25%. All results indicate Tm:GdScO3 a promising candidate for 2 μm tunable and ultrashort lasers.