Full vectorial field sensing using liquid crystal droplet arrays

Abstract: Obtaining the amplitude, phase, and polarization profiles of light beams is essential, with applications spanning metrology, microscopy, astronomy, and optical communication/computing technologies. However, most modern measurement approaches cannot retrieve these parameters easily, often relying on bulky and expensive hardware, or lacking the capability for single-shot sensing. Here, we introduce a compact, snapshot, low-cost, fully vectorial field sensor based on an inkjet-printed nematic liquid crystal droplet array to measure these properties. Polarization and intensity are measured via division-of-wavefront polarimetry, exploiting the droplets' spatially varying birefringence, while the phase is reconstructed by treating each droplet as a microlens in a Shack-Hartmann wavefront sensor configuration. To demonstrate the system's performance, we characterize aberrated dual-wavelength beams carrying distinct intensity, phase, and polarization information, confirming accurate retrieval of the optical field profiles for both spectral components.