高功率大芯径光纤锥的特性研究

对高功率脉冲激光系统中光纤锥的结构、透过率及损伤阈值特性进行了理论研究和实验分析。研究结果表明：光纤锥的几何结构、数值孔径、熔接损耗等都会影响其透过率，通过合理设计光纤锥的几何尺寸，合理选择光纤数值孔径，有效降低熔接损耗，改进拉锥工艺等措施，可以提高光纤锥的透过率；光纤端面的杂质缺陷是造成光纤抗激光损伤能力下降的重要原因，通过改善光纤端面质量，可较大程度地提高光纤锥传输激光的能量。

The Characteristics of High-Power Large Core Diameter Tapered Fiber

The theoretical research and experimental analysis on the structure, transmission, and damage threshold of the tapered fiber in high-power pulse laser system are carried out. The research results show that the transmission of the tapered fiber is influenced by the geometric structure, numerical aperture, fusion loss, etc.. So it is possible to enhance the transmission of the tapered fiber by means of rationally designing the geometry of the tapered fiber, rationally choosing fiber＇s numerical aperture, effectively reducing the fusion loss, and improving the fusion-tapering process. Since the impurity defects in the end-face of the fiber is the important reason to lower the laser damage resistance of the fiber it is possible in a significant extent to enhance the laser power transmitted through tapered fiber by improving the end-face quality of the fiber.