Efficient upconversion-pumped continuous wave Er3+:LiLuF4 lasers
Efficient upconversion-pumped continuous wave Er3+:LiLuF4 lasers
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DOI：
10.1016/j.optmat.2015.01.004
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发表时间：
2015-04
影响因子：
3.9
通讯作者：
F. Moglia;S. Mũller;F. Reichert;P. Metz;T. Calmano;C. Kränkel;E. Heumann;G. Huber
中科院分区：
文献类型：
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作者：
F. Moglia;S. Mũller;F. Reichert;P. Metz;T. Calmano;C. Kränkel;E. Heumann;G. Huber
我们报告详细的光谱调查和有效的可见光上转换激光操作的Er3+：LiLuF4。这种材料允许在974 nm处进行有效的共振激发态吸收（ESA）泵浦。在没有外部反馈的光谱条件下，ESA在552 nm的激光波长处占主导地位的受激发射。在谐振腔中的激光条件下，高的腔内光子密度使ESA在552 nm处漂白，从而允许高效的连续激光器操作。我们获得了任何室温晶体上转换激光器的最高输出功率。该激光器实现了连续输出功率为774 mW的斜率效率为19%，相对于由光泵浦半导体激光器提供的入射泵浦功率。利用波导中的高限制效应，利用飞秒激光脉冲在Er 3+：LiLuF4晶体中刻划了一层平行轨道的改性材料。芯材料允许在泵浦和激光波长下的低损耗波导。在974nm泵浦下，首次实现了晶体上转换波导激光器。我们获得了波导激光器操作高达10 mW的输出功率在553 nm。
We report on detailed spectroscopic investigations and efficient visible upconversion laser operation of Er3+:LiLuF4. This material allows for efficient resonant excited-state-absorption (ESA) pumping at 974 nm. Under spectroscopic conditions without external feedback, ESA at the laser wavelength of 552 nm prevails stimulated emission. Under lasing conditions in a resonant cavity, the high intracavity photon density bleaches the ESA at 552 nm, allowing for efficient cw laser operation.We obtained the highest output power of any room-temperature crystalline upconversion laser. The laser achieves a cw output power of 774 mW at a slope efficiency of 19% with respect to the incident pump power delivered by an optically-pumped semiconductor laser. The absorption efficiency of the pump radiation is estimated to be below 50%.To exploit the high confinement in waveguides for this laser, we employed femtosecond-laser pulses to inscribe a cladding of parallel tracks of modified material into Er3+:LiLuF4crystals. The core material allows for low-loss waveguiding at pump and laser wavelengths. Under Ti:sapphire pumping at 974 nm, the first crystalline upconversion waveguide laser has been realized. We obtained waveguide-laser operation with up to 10 mW of output power at 553 nm.