title: Photoinduced helical inversion in cholesteric liquid crystal cells with homeotropic anchoring.
abstract: Structural changes caused by the optically induced helical inversion in the cholesteric liquid crystal cells with homeotropic anchoring are studied. In a one-step exposure, a sequence of structural transformations "lying left-handed helix - unwound homeotropic state - lying right-handed helix" is realized. In this process, smooth expansion of a left-handed helix, transition to an unwound state, emergence and smooth compression of a right-handed helix was observed. The unwound state was maintained over a rather wide range of exposures. Well-oriented and highly periodic fingerprint textures capable of the above mentioned structural changes were obtained by rubbing the aligning substrates. This allowed for obtaining photo-tunable diffraction gratings and using them to demonstrate new beam steering principle. Also, pitch reversal suggested new options for optical recording, in particular contrast reversal and edge enhancement.
authors.affiliation: Institute of Physics of the National Academy of Sciences of Ukraine, Prospekt Nauki, 46, 03680 Kyiv, Ukraine. igvozd@gmail.com
authors.forename: Igor
authors.initials: I
authors.lastname: Gvozdovskyy
authors.forename: Oleg
authors.initials: O
authors.lastname: Yaroshchuk
authors.forename: Marina
authors.initials: M
authors.lastname: Serbina
authors.forename: Rumiko
authors.initials: R
authors.lastname: Yamaguchi