title: Azobenzene liquid crystalline materials for efficient optical switching with pulsed and/or continuous wave laser beams.
abstract: This study compares optical switching capabilities of liquid crystal (LC) materials based on different classes of azobenzene dyes. LCs based on molecules containing benzene rings with nearly symmetrical pi-pi conjugation respond more efficiently to a cw beam than to a nanosecond laser pulse and maintain the changes induced by the beam for tens of hours. Using azo dye molecules containing two benzene rings with push-pull pi-pi conjugation we demonstrate high photosensitivity to both a cw beam as well as nanosecond laser pulse with only 1 s relaxation of light-induced changes in material properties. Even faster, 1 ms restoration time is obtained for azo dye molecules containing hetaryl (benzothiazole) ring with enhanced push-pull pi-pi conjugation. These materials respond most efficiently to pulsed excitation while discriminating cw radiation.
authors.affiliation: Beam Engineering for Advanced Measurements Co., 809 South Orlando Avenue, Suite I, Winter Park, FL 32789, USA.
authors.forename: Uladzimir A
authors.initials: UA
authors.lastname: Hrozhyk
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Serak
authors.forename: Nelson V
authors.initials: NV
authors.lastname: Tabiryan
authors.forename: Landa
authors.initials: L
authors.lastname: Hoke
authors.forename: Diane M
authors.initials: DM
authors.lastname: Steeves
authors.forename: Brian R
authors.initials: BR
authors.lastname: Kimball