Laser-induced transient stress distribution inside a single crystal by time-resolved birefringence imaging
Laser-induced transient stress distribution inside a single crystal by time-resolved birefringence imaging
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DOI：
10.1117/12.908186
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发表时间：
2012-02
期刊：
影响因子：
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通讯作者：
Takaya Tochio;M. Sakakura;S. Kanehira;Y. Shimotsuma;K. Miura;K. Hirao
中科院分区：
文献类型：
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作者：
Takaya Tochio;M. Sakakura;S. Kanehira;Y. Shimotsuma;K. Miura;K. Hirao
当飞秒激光脉冲聚焦在单晶内部时，各向异性结构变化，例如位错和解理沿着沿着特定取向发生。可以解释，各向异性结构的变化应引起的瞬态应力后，光激发，如热应力和应力波。为了阐明激光诱导晶体内部结构变化的机理，我们研制了一种新型的时间分辨偏振成像系统，该系统采用圆偏振激光脉冲作为探测光。该系统使我们能够观察到激光诱导的瞬态应力分布以及在聚焦飞秒激光脉冲后MgO和LiF单晶内部的取向。在此基础上，阐明了激光诱导瞬态应力分布与晶体内部各向异性结构变化之间的关系。
When femtosecond laser pulses are focused inside a single crystal, anisotropic structural changes such as dislocation and cleavage occur along specific orientations. It can be interpreted that the anisotropic structural changes should be induced by transient stress after photoexcitation, such as a thermal stress and stress wave. To elucidate the mechanism of the laser induced structural changes inside crystals, we developed a novel time-resolved polarization imaging system, in which circularly polarized laser pulse was used as a probe light. The system enabled us to observe laser-induced transient stress distribution as well as the orientation after focusing fs laser pulses inside MgO and LiF single crystals. Based on the observation, we elucidated the relation between laser-induced transient stress distribution and anisotropic structural change inside the crystals.