Random distribution of sagging structure on the surface of substrate is used to induce random screw axes of the chiral liquid crystal, which not only causes blue shift of Bragg reflection but also further stretches the reflection spectra.

• 基片表面的凹凸结构用于诱导液晶螺旋轴的斜向随机分布,以利用倾斜螺旋结构布拉格反射的蓝移现象,进一步展宽布拉格反射谱。