大功率固体激光器高效率光纤耦合

Improving Coupling Efficiency of Optical Fiber for High-Power Laser Beam

光束质量参数对大功率固体激光器光纤耦合系统的设计起着关键作用。大功率固体激光器输出的为多模激光束,引入等效基模光束来计算多模激光束的光束质量是一种有效的方法,并定义包含光斑能量98%的光斑半径为束宽,以此计算多模激光束的光束质量,是准确有效的。结合大功率固体激光器的光纤耦合原理和光束变换理论设计了高效耦合系统,并对系统内透镜的通光孔径及焦距等参量做了数值优化。实验证明,此光纤耦合系统能够进行大功率固体激光高效率耦合,成功地实现了输入功率为2000W时,耦合效率大于94%的激光输出,并给出了光纤耦合的效率曲线及分析。

Beam quality parameter plays an important role in the optical fiber coupling for the high-power laser. For high-power laser, its laser beam is always multimode, so it is an effective method to use equivalent basic mode to replace multimode for calculating. The beam width of this equivalent basic mode is measured by including 98% of the beam energy, and this is an effective way to calculate the beam quality parameter. A high-efficiency coupling system was designed by using theory of optical fiber coupling for the high-power laser and the beam transform, and in the system numerical values of lens＇ aperture and focus were optimized. Experiment proves that the coupling system has a high coupling efficiency. The efficiency is more than 94% when the input power is 2000 W, and the figure of the experiment on coupling efficiency was displayed and analyzed.