title: Polarization switching in a columnar liquid crystalline urea as studied by optical second-harmonic generation interferometry.
abstract: The polar order and its switching characteristics have been investigated by means of optical second-harmonic generation interferometry in a compound N, N'-bis(3,4,5-trialkoxylphenyl)urea (R=n- C16 H33) being connected by intermolecular hydrogen bondings to form a columnar liquid crystalline phase. The polar structure is formed along the column by applying an electric field and is cooperatively switched by reversing the field. The polar order is relaxed to a nonpolar state within a few milliseconds by terminating the field. No macroscopic polar order exists at least in a range of a visible wavelength scale in the absence of a field.
authors.affiliation: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Okada
authors.forename: Shohei
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Takanishi
authors.forename: Ken
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Nakahara
authors.forename: Keiki
authors.initials: K
authors.lastname: Kishikawa
authors.forename: Hideo
authors.initials: H
authors.lastname: Takezoe