Study on the Propagation and Localization of Laser-Superheated Molecules in Organic Solids

将含有荧光分子如蒽、二苯基蒽、二氰基蒽、芘或光致变色分子的聚合物膜（源膜）与纯聚合物膜（目标膜）覆盖，并从目标膜的背面用纳秒脉冲激光照射。这些分子的荧光图案被发现在目标薄膜的表面，即使当激光能量密度小于烧蚀阈值的源膜。从源膜喷射的分子的量由荧光强度的减少来估计。结果发现，源膜的玻璃化转变温度越低，喷射分子的量越高。用全内反射荧光光谱法测定了靶膜表面注入层的厚度。发现分子聚集体的量随着激光照射次数的增加而增加。结合聚合物固体中的光热温度跃变和热激活扩散，讨论了荧光分子在重复辐照下的穿透和聚集机理。

Polymer films involving fluorescent molecules such as anthracene, diphenyl anthracene, dicyano anthracene, pyrene, or photochromic melecules (source films) were overlaid with neat polymer films (target films), and irradiated with nanosecond pulsed laser from the rear of the target films. Fluorescent patterns of these molecules were found at the surface of the target films even when the laser fluence was less than the ablation threshold of the source films. The amount of ejected molecules from the source film was estimated from the reduction of fluorescence intensity. It was found that the lower the glass transition temperature of the source film, the higher the amount of ejected molecules. The thickness of the implanted layr at the surface of the target film was obtained by means of total internal reflection fluorescence spectroscopy. The amount of molecular aggregates was found to increase with increasing the number of laser shots. The mechanism of the penetration and aggregation of the fluorescent molecules by repetitive irradiation was discussed in connection with photothermal temperature jump and thermally activated diffusion in polymer solids.