title: Ultrafast all-optical response of a nematic liquid crystal.
abstract: Liquid crystals are superior optical materials for large area displays, but it is considered that their collective and slow-millisecond response makes them useless for ultrafast optical applications. In contrast to that, we here demonstrate an ultrafast optical response of a nematic liquid crystal, which is induced by an intense femtosecond optical impulse. We show that the refractive index of the nematic liquid crystal pentyl-cyanobiphenyl can be modulated at a time scale as fast as 500 fs via a coherently excited optical Kerr effect. The change in the refractive index is in the order of 10-4at a fluence of 4 mJ/cm2and is strongly polarization dependent. This unprecedented result opens new ways towards ultrafast all-optical modulation in liquid crystal-based devices.
authors.forename: Laura
authors.initials: L
authors.lastname: Cattaneo
authors.forename: Matteo
authors.initials: M
authors.lastname: Savoini
authors.forename: Igor
authors.initials: I
authors.lastname: Muševič
authors.forename: Alexey
authors.initials: A
authors.lastname: Kimel
authors.forename: Theo
authors.initials: T
authors.lastname: Rasing