光学元件“缺陷”对助推放大级光束质量的影响

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 results 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.