Fig. 3: Twist in a +1 radial defect pre-patterned cell.
From: Twist, splay, and uniform domains in ferroelectric nematic liquid crystals
a A polarizing optical microscopy texture (recorded in a monochromatic light using a green filter with 532 nm wavelength and 1 nm bandwidth) of an NF in a cell of the thickness h = 5.5 μm (DIO, temperature T = 60 ∘C). The curved white arrow shows the direction of polarization twist and the anti-parallel arrows indicate the π-twist of P between the top and bottom plates. b Schematic of the polarization P (green arrow) performing a π-twist between the bottom and top cell surfaces (orange). c Fitting the dependence of transmitted light intensity [through a small region in a domain like the red rectangle in a] on the angle γ between the polarizers yields the twist angle τ ≈ 180∘ for samples of different thickness in the range 3 μm < h < 8 μm, demonstrating the π-twist (see Methods). The error bars are the standard deviations of light intensity fluctuations in the measured small regions.
