Ma Weiwei, Yu Xiaoxu, Wang Jiajia, Ma Shihui, Pan Zhongben, Liang Fei, Lu Dazhi, Li Dechun, Hu Zhanggui
Opt Express. 2025 Jul 28;33(15):32918-32928. doi: 10.1364/OE.571705.
Tm-doped sesquioxide crystals represent promising gain media for 2.3 µm lasers owing to their low phonon energy and high thermal conductivity. However, the difficulty in obtaining high-quality crystals and the underdeveloped analysis of energy-transfer upconversion (ETU) processes significantly limit their application in the field of 2.3 µm lasers. To address the crystal quality challenge, we successfully grew Tm:LuO and Tm:LuYO crystals with dimensions of Φ6 × 20-30 mm using the laser floating zone (LFZ) method. Subsequently, we investigated their laser performance at 2.3 µm. Under 793 nm wavelength-locked laser diode (LD) pumping and based on the H→H transition, continuous-wave (CW) 2.3 µm laser operation was demonstrated. The Tm:LuO crystal achieved a maximum output power of 1.1 W with a slope efficiency of 21.7%, while the Tm:LuYO crystal yielded 1.0 W with a slope efficiency of 21%. To the best of our knowledge, these results represent the highest output powers achieved to date from sesquioxide crystals under LD pumping at 2.3 µm and also proves the potential for application in the 2.3 µm band.
掺铥倍半氧化物晶体由于其低声子能量和高导热率，是2.3微米激光器很有前景的增益介质。然而，获得高质量晶体的困难以及能量转移上转换（ETU）过程分析的不完善，显著限制了它们在2.3微米激光领域的应用。为应对晶体质量挑战，我们使用激光悬浮区熔（LFZ）法成功生长出尺寸为Φ6×20 - 30毫米的Tm:LuO和Tm:LuYO晶体。随后，我们研究了它们在2.3微米处的激光性能。在793纳米波长锁定激光二极管（LD）泵浦下，基于H→H跃迁，实现了连续波（CW）2.3微米激光运转。Tm:LuO晶体实现了1.1瓦的最大输出功率，斜率效率为21.7%，而Tm:LuYO晶体输出功率为1.0瓦，斜率效率为21%。据我们所知，这些结果代表了目前掺铥倍半氧化物晶体在2.3微米LD泵浦下所实现的最高输出功率，也证明了其在2.3微米波段的应用潜力。
