Nematic and Chiral Nematic Liquid Crystal Orientation Control in Photonic Liquid Crystal Fibers

摘要

Recently introduced photonic liquid crystal fibers (PLCFs) prove to be excellent materials as all fiber devices in optic fiber telecommunication. PLCFs are a perfect complement the optic communication technology by actively controlled all-fiber devices such as attenuators, polarization or PMD controllers or phase shifters. The control is based on molecular orientation of an liquid crystal (LC) in a PLCF. The most research is devoted to an active control of LC orientation by external fields. A passive control is mostly omitted or assumed to be planar. In this paper we investigate the passive control of LC molecules by using an aligning material between an LC and the inner surface of photonic crystal fiber (PCF) air holes. In the experiment we used commercially available polyimide-SE1211 to induce homeotropic anchoring condition in two different LCs: a 6CHBT nematic LC (NLC) and PW700 chiral nematic LC (CNLC). The aligning material increases and ensures the stability of initial orientation and without external fields the orientation is well defined in photonic liquid crystal fiber-based devices