title: Rotatable diffractive gratings based on hybrid-aligned cholesteric liquid crystals.
abstract: This work proposes a thermally rotatable grating that is based on hybrid-aligned cholesteric liquid crystals (HBA-cholesteric LCs). Experiments reveal that the HBA-cholesteric texture has a uniformly striped domain, which forms a grating, when the ratio of the cell gap to the helical pitch (d/p) is in the range of 2≤d/p≤3. The stripe direction of the HBA-cholesteric grating is predicted by the proposed vertically aligned LC layer model. The stripe direction of the HBA-cholesteric grating rotates continuously under thermal and electrical effects. Furthermore, the HBA-cholesteric grating has a larger rotational angle under the thermal effect (~101°) than under the electrical effect (~48°). Potential applications of the proposed thermally rotatable cholesteric grating for beam steering devices are emphasized.
authors.affiliation: Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
authors.forename: Chi-Huang
authors.initials: CH
authors.lastname: Lin
authors.forename: Ru-Hsien
authors.initials: RH
authors.lastname: Chiang
authors.forename: Shu-Hao
authors.initials: SH
authors.lastname: Liu
authors.forename: Chie-Tong
authors.initials: CT
authors.lastname: Kuo
authors.forename: Chi-Yen
authors.initials: CY
authors.lastname: Huang
mesh_terms: D002784:Cholesterol / Q000737:chemistry*; D003460:Crystallization; D006801:Humans; D050866:Liquid Crystals / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012031:Refractometry / Q000295:instrumentation*
chemical_list: D002784:Cholesterol