Morphology laser ablation dynamics

Coupling between molecular processes and morphological changes is one of the most unique and important characteristics of laser ablation. Excitation energy relaxation dynamics and primary chemical processes of organic molecules in laser ablation have been investigated by using various time-resolved spectroscopies, such as fluorescence, absorption, Raman and IR spectroscopies. Laser ablation leads to rapid temperature elevation of the polymer matrix and thermal decomposition of the polymer. Ablation causes not only photochemical reactions but also photo-initiated thermal reactions. 

One of the designed photolabile triazene polymers (Scheme 8) was selected to test whether a different behavior can be detected for these materials. In this report, decomposition dynamics of the photosensitive triazene polymer film upon intense XeF excimer laser irradiation is studied by applying the nanosecond interferometric technique with a newly improved optical setup. On the basis of the revealed morphological dynamics as well as the obtained time-resolved transmission and reflectance, the ablation mechanism and the dynamics of the triazene polymer film are discussed in detail. 

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