Nematic liquid crystal gyroids as photonic crystals. Issue 13 (7th December 2016)

• Record Type: Journal Article
• Authors: Aplinc, Jure; Štimulak, Mitja; Čopar, Simon; Ravnik, Miha
• Is Part Of: Liquid crystals. Volume 43:Issue 13/15(2016)
• Page Start: 2320
• Page End: 2331
• Publication Date: 2016-12-07
• Subjects: Nematic liquid crystals -- gyroids -- photonic crystals -- topological defects -- chirality; Liquid crystals -- Periodicals; 548.905
• DOI: 10.1080/02678292.2016.1215562
• Languages: English
• ISSNs: 0267-8292

Abstract

ABSTRACT: We demonstrate nematic and cholesteric liquid crystal (LC) gyroids and show their photonic properties as photonic crystals by using numerical modelling. The LC gyroids are designed as composite optical materials, where we take one labyrinth of passages to be a solid dielectric, whereas the other (complementing) labyrinth of passages is taken to be filled by chiral or achiral nematic LC, with the intermediate gyroid surface imposing homeotropic (perpendicular) surface anchoring. The nematic inside the gyroid matrix is shown to exhibit a variety of possible orientational profiles which are characterised by complex networks of topological defects – from ordered, semi-ordered, to completely disordered. The diversity of possible nematic states is shown to lead to a rich structure of photonic bands, which can be tuned by the LC volume fraction and the cholesteric pitch, including control over full – direct and indirect – band gaps. Graphical Abstract: