Photo Alignment of Liquid Crystals by an Azo Dye Doped Reactive Mesogen Layer

Abstract

Azobenzene dye doped reactive mesogen is used as thin photo control layer to align permanently nematic liquid crystal molecules. It is shown that, even in the case of a non mesogenic dye, the reactive mesogen matrix follows its photo induced reorientation rather efficiently. Polarimetric and electrooptic studies are performed to characterize this process. Storage, additional UV and thermal processing are then applied to evaluate, in a first approximation, the reliability of obtained layers.

Keywords:

• Azobenzene dye
• liquid crystal
• photo alignment
• polymer
• reactive mesogens
• surface alignment

Acknowledgment

We acknowledge the financial support of Canadian Institute for Photonic Innovations (CIPI), Fonds Québécois de la Recherche sur la Nature et les Technologies (FQRNT) and Natural Sciences and Engineering Research Council of Canada (NSERC). We also acknowledge the material support from TLCL Optical Research inc.