Electro‐Optic Topological Defect Devices Utilizing Nematic Liquid Crystal Binary Mixtures

Topological defects (TDs) manifest in many condensed matter systems. In liquid crystals (LCs), they occur as point or line singularities in the otherwise smooth director profile. Engineered and controllable TDs are of great interest for functional optoelectronic devices; however, the formation mechanism in patterned devices is not fully understood. In this work, electrically addressable TDs in doped mixtures of prototypical n‐alkyl‐cyanobiphenyl LCs 4‐cyano‐4′‐pentylbiphenyl (5CB) and 4‐cyano‐4′‐octylbiphenyl (8CB) are focused on. Doping concentrations of hexadecyltrimethylammonium bromide (CTAB) are varied and the effect of varying the host LC properties (through binary 5CB:8CB mixtures) on defect formation is studied. In the results, a strong correlation between LC “fluidity” and the ease of defect array formation is presented, with 0.5 wt% CTAB‐doped 5CB giving the best controllability/uniformity of TDs at low‐threshold voltages. Furthermore, it is demonstrated that the devices can be utilized as electrically switchable optical diffractive elements. In these findings, directions are mapped out that future studies can take in designing deterministic, electrically or magnetically tunable TD‐based photonic devices using LC systems.

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch

References and Relationships

• Bibliographic citation: Electro‐Optic Topological Defect Devices Utilizing Nematic Liquid Crystal Binary Mixtures ; day:29 ; month:12 ; year:2023 ; extent:9 ; Advanced photonics research ; (29.12.2023) (gesamt 9)

Contributors, Places and Time

• Creator: Arif, Mariam ; Bano, Afsar ; Ulhaq, Ata ; Khan, Ammar A.

Further information

• DOI: 10.1002/adpr.202300336
• URN: urn:nbn:de:101:1-2023123014102115432137
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 15.08.2025, 7:25 AM CEST