Electrically tuneable optical diffraction gratings based on a polymer scaffold filled with a nematic liquid crystal

Bošnjaković, Dejan (avtor), Fleisch, Mathias (avtor), Zhang, Xinzheng (avtor), Drevenšek Olenik, Irena (avtor)

We present an experimental and theoretical investigation of the optical diffractive properties of electrically tuneable optical transmission gratings assembled as stacks of periodic slices from a conventional nematic liquid crystal (E7) and a standard photoresist polymer (SU-8). The external electric field causes a twist-type reorientation of the LC molecules toward a perpendicular direction with respect to initial orientation. The associated field-induced modification of the director field is determined numerically and analytically by minimization of the Landau–de Gennes free energy. The optical diffraction properties of the associated periodically modulated structure are calculated numerically on the basis of rigorous coupled-wave analysis (RCWA). A comparison of experimental and theoretical results suggests that polymer slices provoke planar surface anchoring of the LC molecules with the inhomogeneous surface anchoring energy varying in the range 5–20 µJ/m$^2$. The investigated structures provide a versatile approach to fabricating LC-polymer-based electrically tuneable diffractive optical elements (DOEs).

• Jezik: Angleški jezik
• Ključne besede: polymers, nematic liquid crystals, optics, diffraction gratings, photoresist polymeric materials, laser-based micro structuring, diffractive optical elements
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FMF - Fakulteta za matematiko in fiziko
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2021
• Št. strani: 17 str.
• Številčenje: Vol. 13, iss. 14, art. 2292
• PID: 20.500.12556/RUL-144726
• UDK: 535.421
• ISSN pri članku: 2073-4360
• DOI: 10.3390/polym13142292
• COBISS.SI-ID: 71504131
• Datum objave v RUL: 09.03.2023

Gradivo je del revije

• Naslov: Polymers
• Skrajšan naslov: Polymers
• Založnik: MDPI
• ISSN: 2073-4360
• COBISS.SI-ID: 517951257

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: polimeri, nematski tekoči kristali, lasersko mikrostrukturiranje, optika, uklonske mrežice