共查询到6条相似文献,搜索用时 62 毫秒
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采用脉冲数字显微全息技术,对50 fs单脉冲激光烧蚀铝靶过程中的物质喷射以及等离子体演化的动态过程进行了实验研究,获得了高时空分辨的动态数字全息图.由全息图观察到了热弹力波引起的二次喷射现象,并且报道了大延迟下喷射物质对400 nm探测光所引起的干涉条纹的反常移动现象.通过对全息图进行数字再现,得到了不同延迟下探测光穿过等离子体后的二维相位分布,并运用逆Abel变换算法获得了等离子体折射率以及等效电子密度的时空演化动态过程.根据实验以及计算所得到的有关于喷射物的光学性质,对喷射物的结构和成分进行了分析.
关键词:
脉冲数字全息
飞秒激光烧蚀
超快时间分辨
等离子体 相似文献
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超短脉冲照射下氟化锂的烧蚀机理及其超快动力学研究 总被引:7,自引:0,他引:7
研究了超短脉冲激光照射下LiF晶体的破坏机理及其超快动力学过程,利用扫描电镜和原子力显微镜等测试手段,观测了飞秒激光照射下LiF晶体的烧蚀形貌。利用烧蚀面积与激光脉冲能量的对数关系确定了LiF晶体的破坏阈值,并利用非线性玻璃棒展宽脉宽,得到了800nm激光作用下LiF破坏阈值对激光脉宽(50~1000fs)的依赖关系;利用抽运一探针超快探测平台,探测了LiF烧蚀过程中反射率的变化。采用雪崩击穿模型,并根据晶体材料反射率与材料的介电常量的依赖关系,通过数值计算,模拟了材料烧蚀阈值与脉宽的依赖关系及材料激发过程中反射率的变化关系。结果表明,理论结果与实验结果符合较好。讨论了飞秒激光照射下LiF晶体中导带电子数密度的变化规律,并解释了相应的实验结果。 相似文献
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The influence of nonparaxiality on the spectral behavior in Young's experiment illuminated by partially coherent light 下载免费PDF全文
Starting from the Rayleigh--Sommerfeld diffraction integral, this
paper studies the spectral behavior in Young's experiment
illuminated by nonparaxial partially coherent light and compares
with the paraxial case, where the influence of nonparaxiality of
partially coherent light on the spectral shifts and spectral
switches is stressed. It is shown that there is a spectral shift in
the nonparaxial case relative to the paraxial one and the critical
position changes, at which the spectral switch occurs. The ratio of
the waist width to the central wavelength w0/λ0 and
relative spatial correlation length \De affect the spectral
difference. The smaller w0/λ0 is, the larger the
difference between the nonparaxial and paraxial results appears. The
effect of relative spatial correlation length Δ is relatively
small. 相似文献
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Chunyuan Zhou Loc Le Xuan Abdallah Slablab Nicolas Sandeau Sophie Brasselet Dominique Chauvat Jean-Franois Roch 《中国光学快报(英文版)》2008,6(1):64-67
The finding of nonlinear nanometric-sized probes is of key importance for the development of nonlinear microscopy in physical as well as biological sciences. We isolate nonlinear KTiOPO4 nanocrystals and study them by second-harmonic generation microscopy (SHGM) and atomic force microscopy (AFM) independently. With both polarization analysis and defocused imaging of the emitted second harmonic field, we extract the Euler angles of the crystalline axes of a single nanocrystal. A balanced coherent optical homodyne detection shows the coherent nature of the nanocrystal nonlinear emission and allows a phase measurement of the emitted second-harmonic field. These features make the KTiOPO4 nanocrystal a good candidate for a vectorial probe of electromagnetic near fields. 相似文献