Figure 3

Gleaming defects in a NLC doped with LMW fluorescent probe confined within open capillary grooves, System-(ii).

(a) Schematic for the filament of a NLC formed on an open capillary groove accommodating a zigzag disclination line with m = +1/2 shown by green lines (see ref. 12 for the detailed alignment structure). The top air interface imposes homeotropic (normal) alignment to the NLC. The bottom curved surface imposes anisotropic planar alignment lying in the xz plane along the sinusoidal cross section. Under this semi-hybrid alignment condition and the sign of the curvature of the groove, disclination lines with m = +1/2 stably form. The curved solid lines indicate the orientation of n. Twist deformations of n formed under the defect lines are not shown for simplicity. (b) Surface profiles of the open capillary with (green line) and without (black line) the NLC filaments. Representative (c) POM and (d) FOM images showing zigzag line defects with m = +1/2, appearing as gleaming zigzag lines in the FOM image. (Scale bar: 20 μm.) (e) A representative CLS-FOM image and the cross sectional images in the xz plane, in which the region occupied by the NLC in the xz plane is indicated by yellow broken lines in the magnified image (right). It is indicated that the gleaming line runs halfway between the top air surface and the bottom surface of the NLC filament, that is, the line defect gleams. The positions of xz and yz cross sections are indicated by white arrows. (Scale bar: 10 μm).