title: Measurement of helical twisting power based on axially symmetrical photo-aligned dye-doped liquid crystal film.
abstract: This investigation demonstrates a simple but accurate method for measuring the helical twisting power of chiral doped liquid crystals using axially symmetrical photo-alignment in azo dye-doped liquid crystal films. As reported in our previous paper, a reversed twist effect produces a disclination line in photo-aligned axially symmetrical liquid crystal films. The pitch and helical twisting power can be obtained by measuring the rotation angle of the disclination line in chrial doped liquid crystal. This method is independent of cell gap and provide an error below 0.5%.
authors.affiliation: Institute of Electro-optical Science and Engineering, National Cheng Kung University, Tainan, Taiwan 701, ROC.
authors.forename: Shih-Wei
authors.initials: SW
authors.lastname: Ko
authors.forename: Shu-Hao
authors.initials: SH
authors.lastname: Huang
authors.forename: Andy Y-G
authors.initials: AY
authors.lastname: Fuh
authors.forename: Tsung-Hsien
authors.initials: TH
authors.lastname: Lin