Self-assembled optical gratings with banana-shaped liquid crystals
We demonstrated that a homologous series of bananashaped liquid crystals, 1,3-phenylene bis(4-alkyloxybenzylideneamine), could assemble themselves into various kinds of groove-free diffraction gratings when their isotropic melts were slowly cooled into mesophases between two pieces of glass substrates. The groovefree diffraction gratings included one-dimensional parallel gratings, two-dimensional crossed gratings, two-dimensional fan-shaped gratings and two-dimensional circular gratings. Characterization by means of polarized optical microscopy showed that a pattern of periodic modulation of the refractive index was developed in the thin films formed by the banana-shaped compound. Our laser light diffraction experiments confirmed that these groove-free gratings could effectively diffract the incident red light from a helium-neon laser. On the basis of the diffraction equations derived for the self-assembled groove-free optical gratings, the diffraction patterns were simulated for the parallel gratings, orthogonally crossed gratings, fan-shaped gratings and circular gratings, respectively, and good agreement was achieved. The mechanisms on the self-assembly of the bananashaped molecules were discussed in terms of intermolecular interactions. Our work provides an alternative method for manufacturing diffraction gratings by harnessing the self-assembly of bananashaped molecules.
Banana-shaped liquid crystal Self-assembly Polarized optical microscopy Diffraction grating Fan-shaped grating Circular grating Orthogonally crossed grating
Yuan Ming Huang
College of Physics & Electronic Information, Yunnan Normal University, Yunnan 650092,China
国际会议
2009 International Symposium on Liquid Crystal Science and Technology(2009国际液晶科技研讨会)
昆明
英文
12-23
2009-08-02（万方平台首次上网日期，不代表论文的发表时间）