Controlling Topological Defects and Disclinations in Liquid Crystals Through Structured Polymerization

Line singularities in nematic Liquid Crystals (LC) known as disclinations play an important role in the understanding of topography and electro-optic phenomena in LC technologies. Manipulating these singularities and defects in a precise and controlled way can unlock new functionality and electro-optic behavior in LC devices for a range of applications including tunable lasers and beam generators for optical communications. In this presentation, we demonstrate the control of disclinations and defects using a combination of bulk photopolymerization using an optical projection system and localized polymerization using direct laser writing. We use a so-called nematic LC Pi cell to show how this control of the disclinations and defects could be used as an effective template for transferring biological matter. An extensive study has been conducted to analyze the nucleation and growth processes, highlighting the significant influence of rubbing direction on the formation of random domains. By modulating the Pi cell, distinct states with varying boundary conditions are generated. This characteristic makes the Pi cell a promising platform for the manual manipulation of nanoparticles within an electro-optical waveguide. We anticipate that our disclination movement technique can lead to tunable metamaterials, LC plasmonic devices and more efficient optical phase modulators.