We present our efforts towards power scaling of Er:Lu₂O₃ lasers at 2.85 µm. By applying a dual-end diode-pumped resonator scheme, we achieve an output power of 14.1 W at an absorbed pump power of 59.7 W with a slope efficiency of 26%. In a single-end pumped resonator scheme, an output power of 10.1 W is reached under 41.9 W of absorbed pump power. To the best of our knowledge, this is the first single crystalline mid-infrared rare-earth-based solid-state laser with an output power exceeding 10 W at room temperature.

3~5 μm中红外波段是一个极特殊的电磁波谱区间，它不仅覆盖着众多分子与原子的本征吸收峰，同时还是大气透明窗口之一。此波段的激光器在气体探测、生物医疗、**等众多领域都具有很大的应用前景。文中围绕常用于3~5 μm光纤激光产生的三种稀土离子（即Er³⁺、Ho³⁺和Dy³⁺），对基于这些离子掺杂的连续和脉冲中红外光纤激光器的发展现状进行了梳理，最后对3~5 μm掺稀土离子光纤激光器的发展进行了展望。

采用自行研制的776.9 nm半导体激光器作为种子源, 经过锥形半导体放大器并整形后得到2.3 W的基频光,再利用Ⅰ类相位匹配的三硼酸锂晶体和蝶形倍频腔产生了388.4 nm紫外连续激光。分析了锥形放大器中热透镜效应对光束质量的影响, 并通过透镜、柱面镜、棱镜对光束进行整形, 提高了倍频腔的输入耦合效率。进一步通过优化倍频腔的束腰尺寸和腔参数, 提高了紫外激光二次谐波的转换效率。最终2.3 W的基频光产生940 mW的紫外倍频光输出, 倍频效率达到41%。

A continuous-wave (CW) π-polarized 1084 nm laser based on Nd:MgO:LiNbO3 under 888 nm thermally boosted pumping is reported. According to the absorption spectrum and energy level structure of Nd:MgO:LiNbO3, the 888 nm laser diode (LD) is used for thermally boosted pumping. This pumping method eliminates the quantum defect caused by the nonradiative transition in Nd:MgO:LiNbO3 under the traditional 813 nm pumping and effectively improves the serious thermal effect of the crystal. The unmatched polarized 1093 nm laser is completely suppressed, and the π-polarized laser output of 1084 nm in the whole pump range is realized by the 888 nm thermally boosted pumping. In the present work, we achieved the CW π-polarized 1084 nm laser with a maximum output power of 7.53 W and a slope efficiency of about 46.1%.