Li C H, Ju X, Jiang X D, Huang J, Zhou X D, Zheng Z, Wu W D, Zheng W G, Li Z X, Wang B Y, Yu X H
Department of Physics, University of Science and Technology Beijing, Beijing 100083, China.
Opt Express. 2011 Mar 28;19(7):6439-49. doi: 10.1364/OE.19.006439.
We report on the characterization of modifications in fused silica after exposure to low fluence (2 J/cm2) 355 nm laser at repetition frequencies of 1 Hz, 5 Hz and 10 Hz. Synchrotron based XRF spectroscopy is employed to study concentration variation of metal inclusions in the surface layer. Positron annihilation lifetime spectroscopy is used to probe atomic size defects variation in bulk silica. FT-IR is used to characterize changes of bond length and angle of Si-O-Si covalent bond of irradiated silica. Compared to the basic frequency, the big loss of cerium and iron concentration, the size enlargement of vacancy cluster and the decrease of Si-O-Si covalent bond length after 10 Hz laser irradiation are illustrated by our data. These tiny modifications provide important data to investigate laser damage mechanism.
我们报告了在重复频率为1Hz、5Hz和10Hz的低能量密度（2J/cm²）355nm激光辐照后熔融石英中改性的表征情况。采用基于同步加速器的X射线荧光光谱法研究表层中金属夹杂物的浓度变化。正电子湮没寿命光谱法用于探测块状石英中原子尺寸缺陷的变化。傅里叶变换红外光谱法用于表征辐照石英中Si-O-Si共价键的键长和键角变化。与基频相比，我们的数据表明，在10Hz激光辐照后，铈和铁浓度大幅降低、空位团簇尺寸增大以及Si-O-Si共价键长度减小。这些微小的改性为研究激光损伤机制提供了重要数据。
