source from：
Ji-Liang Zhu, Jian-Gang Lu, Jing Qiang, En-Wei Zhong, Zhi-Cheng Ye, Zhenghong He, Xiaojun Guo, Cheng-Yuan Dong, Yikai Su, and Han-Ping D. Shieh, “1D/2D switchable grating based on field-induced polymer stabilized blue phase liquid crystal”, Journal of Applied Physics, 111(3), 033101, 2012
