摘要
光学元件"缺陷"制约着高功率固体激光装置负载能力的提升。从统计角度建立了振幅调制型"缺陷"模型,并针对神光Ⅲ原型装置助推放大级分析了"缺陷"分布的统计参量与光束近场质量的关系,得到了一般规律。结果表明,"缺陷"总密度的增加和幂指数的减小都使系统输出光强的中高频成分增加,光束近场质量变差;总密度的变化引起光强各中高频成分变化的幅度近似相等,频率间相对比重基本保持不变,幂指数的变化却会引起各频率间相对比重发生变化;一定范围内,"缺陷"尺寸越大对近场质量的影响越严重;对于助推段,需将元件的"缺陷"总密度控制在600cm-2以下,幂指数控制在2.5以上。研究结果可为降低元件的损伤风险以提高系统的运行负载提供参考。
The ＂defects＂ on optics is the main limiting factor in enhancing the power of a high power solid-state laser system. This paper established a ＂defects＂ model about amplitude modulation based on statistics. Aimed at the booster of SG-Ⅲ prototype, the relationship between characteristic parameters of the model and the near-field quality of the beam was studied. The re- suits show that, both the increase of total density of ＂defects＂ and the decrease of power exponent can cause the degradation of beam quality~ for median-high frequency, different total densities of ＂defects＂ have approximately equal effects, while the effects of different power exponents vary; the larger ＂defects＂ can lead to more serious degradation of beam quality; for the booster, it is necessary to control the total density of ＂defects＂ under 600 cm^-2 , and the power exponent above 2.5. These results provide a guidance for reducing optics damage risk to enhance system power.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2009年第3期326-330,共5页
High Power Laser and Particle Beams
基金
中国工程物理研究院科学技术发展基金资助课题(2007B08005)
关键词
高功率固体激光器
光学元件
“缺陷”
光束质量
助推放大级
统计模型
high power solid-state laser
optical components
＂defects＂
beam quality
booster amplification
statistical model
