Topographical control of pattern formation in a nematic liquid crystal prepared by laser-processed surface

Electric field applications and surface boundary conditions play important roles in controlling the molecular orientation of nematic liquid crystals. Spatially periodic director modulation in a microscopic area is useful for optical applications, such as polarization conversion. In this study, we demonstrate an efficient method to control the pattern formation of a nematic liquid crystal by varying the thickness of the electrode using a pulsed laser. Laser-processed spots preferentially induce defects owing to nanoscale topographical effects. This approach can be used not only to expand uniform patterns but also to stabilize various structures that are useful for optical studies.