Regensburg 2004 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 1: Elektrische und optische Eigenschaften I

DF 1.1: Hauptvortrag

Montag, 8. März 2004, 09:30–10:10, H11

Ferroelectric liquid crystals: Electrooptical modes and applications — •Wolfgang Haase — Technische Universität Darmstadt, Institut für Physikalische Chemie, Petersenstr. 20, 64287 Darmstadt

Ferroelectric Liquid Crystals are chiral mesophases arranged in a two-dimensional layered structure (SmC). Due to the absence of mirror symmetry, the electrical dipole moment within each layer is macroscopically non compensated, hence the external electrical field can interact. For application in devices or displays the FLC’s are promising candidates due to short switching time in the microsecond range, large viewing angle etc, but there are hardly to align compared to nematics. Nowadays there are several electrooptical modes among them the recently discovered V-shape switching mode allowing grey scaling and the high frequency DHF (Deformed Helical Ferroelectric) mode. Principal aspects of applying such modes for various devices for telecommunication, image processing, polarimetry and displays will be demonstrated. Along the talk it will be shown how FLC’s are usable for tunable mirrorless lasing. Short pitch mixtures allowing the stop band in the visible range were prepared.