Complex structured light generation using printed liquid crystal droplets

Abstract

Inkjet-printed liquid crystal (LC) droplets exhibit an intricate spatially-varying birefringence due to their complex internal director configuration. While such anisotropy is often viewed as a drawback when LC droplets are used as microlenses, here we leverage this remarkable birefringence property to generate complex structured light. Through a selection of the alignment layer, and by varying the chiral pitch, we create three distinct droplet types with tailored intrinsic director configurations, each exhibiting a unique birefringence distribution for structured light beam generation. We show that these printed LC droplets can generate beams that exhibit skyrmionic structures carrying two units of orbital angular momentum, beams that contain azimuthal/radial polarized fields, and beams with polarization singularities. Our method enables new possibilities for using LC droplet technology to engineer sophisticated optical beam patterns.