The effect of polarized violet light on the alignment and the heliconical pitch of a liquid crystal dimer containing both sulfur atoms and an azo linkage has been studied by tender resonant x-ray scattering. The results provide evidence of the manipulation of the nanoscale heliconical structure by polarized light. In addition to the bulk alignment of the heliconical nanostructure, the value of the heliconical pitch can be varied as well. After turning the light on, an increase of the pitch is observed in two steps. The increase with a subsecond timescale is attributed to the reduced heliconical order related to trans-cis photoisomerization. This is followed by a smaller increase over a 10-s timescale, which is likely related to the annihilation of defects. After turning the light off, the pitch first decreases within a few seconds to a value larger than the original (before illumination), and then relaxes further on a much longer (hours) timescale.

中文翻译：

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用偏振光处理扭曲弯曲向列材料的纳米螺旋结构

已经通过嫩共振x射线散射研究了偏振紫光对同时包含硫原子和偶氮键的液晶二聚体的取向和螺线间距的影响。结果提供了偏振光对纳米螺旋结构的操纵的证据。除了螺旋形纳米结构的整体排列，螺旋形螺距的值也可以变化。打开灯后，分两步观察到音高的增加。以亚秒级的时间尺度的增加归因于与降低heliconical顺序反式-顺光异构化。接下来是在10秒的时间范围内较小的增加，这很可能与缺陷的an没有关。关掉灯后，音调首先在几秒钟内减小到大于原始值（在照明之前），然后在更长（数小时）的时间尺度上进一步放松。