Laser-stimulated desorption from CaF2 crystals
Laser-stimulated desorption from CaF2 crystals
复制标题
CaF2 晶体的激光刺激解吸
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
M. Reichling
中科院分区：
文献类型：
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作者：
E. Matthias;S. Gogoll;E. Stenzel;M. Reichling
本文用532 nm的纳秒激光脉冲研究了光学级CaF_2中中性粒子和正离子的光透射和激光诱导脱附。发现了两种不同的发射特性：一种是传输的击穿与消融的发生相一致;另一种是传输击穿发生在比消融阈值低约20-30%的注量处。在后一种情况下，传输击穿伴随着延迟（十分之一秒）的粒子发射。我们提出，低于烧蚀阈值的粒子发射是缺陷辅助LID，在这个意义上，预先存在的缺陷的光吸收导致局部加热和热膨胀，导致粒子从其中喷出的微裂纹。
Abstract Optical transmission and laser-induced desorption (LID) of neutral particles and positive ions from opticalgrade CaF2 has been studied, using nanosecond laser pulses of 532 nm. Two different emission characteristics were found: one for which the breakdown of transmission coincides with the onset of ablation; and another for which the transmission breakdown occurs at about 20–30% lower fluences compared to the ablation threshold. In the latter case the transmission breakdown is accompanied by delayed (tenths of seconds) particle emission. We propose that the particle emission below the ablation threshold is defect-assisted LID, in the sense that light absorption by preexisting defects leads to local heating and thermal expansion, causing microcracks from which particles are ejected.