Memory in nonlinear ionization of transparent solids
Memory in nonlinear ionization of transparent solids
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DOI：
10.1103/physrevlett.97.253001
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发表时间：
2006-12-22
影响因子：
8.6
通讯作者：
Corkum, P. B.
中科院分区：
文献类型：
--
作者：
Rajeev, P. P.;Gertsvolf, M.;Corkum, P. B.
我们展示了强飞秒脉冲照射下大块玻璃电离阈值激光强度的逐次降低。对于 SiO2，阈值变化充当正反馈，强化了产生它的过程。这构成了材料非线性电离的记忆。阈值变化随着给定点处入射的脉冲数量而饱和。无论脉冲能量如何，饱和阈值变化的幅度都是恒定的（类似于 20%）。然而，达到饱和所需的发射次数确实取决于脉冲能量。电离记忆的识别对于理解电介质中的多重光学或电击穿现象至关重要。
We demonstrate a shot-to-shot reduction in the threshold laser intensity for ionization of bulk glasses illuminated by intense femtosecond pulses. For SiO2 the threshold change serves as positive feedback reenforcing the process that produced it. This constitutes a memory in nonlinear ionization of the material. The threshold change saturates with the number of pulses incident at a given spot. Irrespective of the pulse energy, the magnitude of the saturated threshold change is constant (similar to 20%). However, the number of shots required to reach saturation does depend on the pulse energy. Recognition of a memory in ionization is vital to understand multishot optical or electrical breakdown phenomena in dielectrics.