Sabel Tina
Department of Chemistry, Technische Universität Berlin, Strasse des 17. Juni 135, Berlin 10623, Germany.
Polymers (Basel). 2017 May 30;9(6):198. doi: 10.3390/polym9060198.
In order to further understand the mechanism of volume hologram formation in photosensitive polymers, light-induced material response is analyzed in commonly used epoxy-based negative photoresist Epon SU-8. For this purpose, time-resolved investigation of volume holographic grating growth is performed in the SU-8 based host⁻guest system and in the pure SU-8 material, respectively. The comparison of grating growth curves from doped and undoped system allows us to draw conclusions on the impact of individual components on the grating formation process. The successive formation of transient absorption as well as phase gratings in SU-8 is observed. Influence of exposure duration and UV flood cure on the grating growth are investigated. Observed volume holographic grating formation in SU-8 can be explained based on the generation and subsequent diffusion of photoacid as well as time-delayed polymerization of exposed and unexposed areas.
为了进一步了解光敏聚合物中体全息图的形成机制,在常用的环氧基负性光刻胶Epon SU-8中分析了光诱导的材料响应。为此,分别在基于SU-8的主客体系统和纯SU-8材料中对体全息光栅的生长进行了时间分辨研究。掺杂和未掺杂系统的光栅生长曲线比较使我们能够得出关于各个组分对光栅形成过程影响的结论。观察到SU-8中瞬态吸收以及相位光栅的连续形成。研究了曝光持续时间和紫外泛光固化对光栅生长的影响。基于光酸的产生和随后的扩散以及曝光和未曝光区域的延迟聚合,可以解释在SU-8中观察到的体全息光栅的形成。