レーザーアブレーション機構解明のためのナノ秒形態観察・分光システムと解析法の確立

材料与光的相互作用所引起的光物理和光化学现象受到了广泛的关注，21世纪被认为是“光的世纪”。我们通过超快光谱、微光谱、光反应、光学操作等方法对薄膜、微晶粉末、聚合物微球等有机材料进行了研究，发现材料在高强度激光激发下经常发生形态变化。这种形态动力学不仅从光物理和光化学的角度来看是非常有趣和重要的，而且对于阐明材料结构和性质的动态方面也是非常重要的。在本工作中，我们将迈克尔逊干涉术与纳秒激发和探测激光相结合，发展了纳秒干涉术。系统的空间和时间分辨率分别为20 nm和10 ns。将干涉法揭示的形态动力学与时间分辨吸收光谱和荧光光谱数据进行了比较，并对其进行了详细的研究，从而开辟了分子光科学的新阶段。新方法的发展“循环多光子吸收”光热烧蚀机理的建立光化学烧蚀机理的建立聚合物薄膜的膨胀/收缩动力学聚合物的光分解反应和蚀刻动力学

Photophysical and photochemical phenomena due to interactions of materials with light have received much attention and the 21st century is considered to be "Century of Light". We have devoted our efforts to the studies on organic materials including films, microcrystalline powders, polymer microspheres, and so on by ultrafast spectroscopy, microspectroscopy, photoreaction, and optical manipulation, during which we found that materials often undergo morphological changes due to high intensity laser excitation. This morphological dynamics is very interesting and important not only from photophysical and photochemical viewpoints but also for elucidating the dynamic aspects of structures and properties of materials.In the present work, we have developed nanosecond interferometry by combining Michelson interferometry with nanosecond excitation and probe lasers. The spatial and temporal resolutions of our system are 20 nm and 10 ns, respectively. Morphological dynamics revealed by the interferometry is compared with time-resolved absorption and fluorescence spectroscopic data and considered in detail, which is opening a new stage of molecular photoscience.Development of a new methodologyEstablishment of photothermal ablation mechanism by "cyclic multiphotonic absorption"Establishment of photochemical ablation mechanismExpansion/contraction dynamics of polymer filmPhotodecomposition reaction and etching dynamics of polymers