摘要
实验研究了光纤传输调QNd:YAG高功率脉冲激光特性,包括光纤的传输效率、输出光束特性、输出光斑能量分布以及激光诱导损伤特性。得出的主要结论为:光纤传输高峰值功率激光引起受激拉曼散射(SRS)和受激布里渊散射(SBS)的产生是导致传输效率下降的主要原因;光纤输出光束束腰位置为输出端面,发散角略大于入射角,光束质量下降,输出光束截面光斑能量分布"匀化";光纤的端面激光损伤限制了传输激光功率的提高,其主要损伤相貌分为—坑状损伤、熔融损伤和溅射损伤,实验得出光纤端面的激光零损伤概率阈值功率密度为3.85GW/cm2。
The fiber delivery characteristics of Q-switch Nd：YAG high power pulse were investigated by experiments, including transmission efficiency, characteristics of output beam, distribution of output beam and laser induced damage to fiber end. Many conclusions were obtained as follows. SRS and SBS induce the decrease of transmission efficiency.Output beam waist is on the fiber output end, and the divergence angle is a little larger than input beam＇s. Quality factor is degraded, the distribution of output beam is uniform.Laser induced damage to fiber ends limits the raising of laser power passing through fibers.The damage figures include that pit damage, fusion damage, and sputtering damage.The combination method of N-ON-1 and 1-ON-1 test modes to LIDT tests was introduced. The plasma sparks at the fiber end faces indicated the fiber damage. The zero probability damage threshold was calculated according to experimental results, that is 3.85 GW/cm^2. The LIDT and the nonlinear effects of fibers are the main factors in limiting the power capacity of fiber delivery laser system.
出处
《红外与激光工程》
EI
CSCD
北大核心
2008年第3期444-448,共5页
Infrared and Laser Engineering
基金
中物院科学技术发展基金重点课题(2007A05001)
国防预研项目课题(51305070402)
中物院电子工程研究所科技创新基金资助(S20070202)
关键词
光纤传能
激光损伤
高峰值激光
质量因子
Fiber delivery laser energy
Laser damage
High peak power laser
Quality factor
