全息光栅液晶排列性质与厚度关系相关的研究(英文)

Study on the Alignment Properties and the Thickness of Liquid Crystal on Holographic Grating

利用电子扫描显微镜和极化光学显微镜,研究了全息光栅液晶向列(LC)排列的性质和厚度之间的关系。研究发现,随着LC厚度的增加,LC排列的性质变化很大。单向的LC不是沿厚度小(d<1.0)或大(d>10μm)的纹沟方向,而是沿着中等厚度(1<d<10μm)的细微纹沟方向排列。这种厚度相关的LC排列性质可以解释为细微纹沟的物理限制效应和额外表面的浮雕脊的锚效应竞争的结果。

Using scanning electron microscope and polarizing optical microscope, the author investigates the relationship between the alignment properties of a nematic liquid crystal (LC) and the thickness of the LC layers on a holographic grating. As the thickness of the LC layer (d) increases, the LC alignment properties are found to change dramatically. Unidirectional LC alignment is achieved along the microgrooves only for moderately thick LC layers (1 < d<10 μm), but not for thin (d<1.0 μm) or thick (d>10 μm) LC layers. The thickness-dependent LC alignment properties are explained in terms of the competitions between the microgroove-introduced physical confinement effect and the embossed-ridge introduced extra surface anchoring effect.