Fig. 4: Fine structure of 360o DW pairs.
From: Soliton walls paired by polar surface interactions in a ferroelectric nematic liquid crystal
a Polychromatic texture of a DW pair running parallel to one of the crossed polarizers; wide P ↑↓ R (φ = 0, 2π) and narrow P ↓↓ R (φ = π) domains are extinct. b The same texture, observed with a blue filter; the stripes with φ = π/2 and 3π/2 where P is perpendicular to the DWs are also extinct. c Transmitted light intensity along the dashed line in (b). d Polychromatic texture of a DW pair running at 45o to the crossed polarizers; wide P ↑↓ R (φ = 0, 2π) and narrow P ↓↓ R (φ = π) domains show similar optical retardance. e The same texture, observed with a red filter that yields destructive interference at locations φ = 0,π/2, π, 3π/2, 2π. f Transmitted light intensity along the dashed line in (e). Cell thickness 6.8 µm in all textures.
