Liquid crystals microlens array using chiral ligand capped Au nanoparticles*

Recently, Popov et al. [1] showed that a flat film of liquid crystal 4-cyano-4’-pentylbiphenyl (5CB) mixed with chiral dopant S811 suspended in sub-millimeter size grids could spontaneously form biconvex microlenses when they were fully immersed in water. Here we present the optical properties of microlenses array by addition of chiral nanoparticles. The helical twisting power of the chiral ligand-capped nanoparticles is about 400 µm^-1, greater than that of the strongest molecular chiral dopants [2]. By studying the optical properties of these microlens arrays, we show that it is possible to calculate the helical twisting power of the chiral ligand-capped nanoparticles using only minimal amount of materials compared with conventional methods such as Grandjean-Cano wedge or contact cell.

References
[1] P. Popov, L. W. Honaker, M. Mirheydari, E. K. Mann, and A. Jákli, Chiral Nematic Liquid Crystal Microlenses, Sci. Rep. 7, 1603 (2017).
[2] K. Perera, A. Nemati, E. Mann, T. Hegmann, and A. I. Jákli, Optical Properties of Nematic Microlenses Doped with Chiral Nanoparticles, Proc. SPIE 11472, Liquid Crystals XXIV, 114720O (20 August 2020)