Optical Poling of Ferroelectric Liquids

Ferroelectric nematic liquid crystals combine fluidity, spontaneous polarity, optical birefringence, and strong nonlinear response, unlocking a rich landscape of phenomena and control strategies yet to be fully explored. Here, all‐optical manipulation of polar domains and topological textures in ferroelectric nematic cells assembled from lithium niobate plates is demonstrated. In these devices, the photovoltaic response of the solid substrate couples to the fluid's polar director, enabling light‐driven reorganization of the ferroelectric alignment. Under focused illumination in parallel‐rubbed cells, the emergence of submillimeter‐scale spiral‐shaped radial domains is observed, in excellent agreement with the underlying material properties. Furthermore, it is shown that both domain structures and wall configurations can be reversibly reconfigured by varying light exposure, thereby tuning the degree of domain fragmentation and wall unpinning. These results establish light‐induced polarization patterning as a versatile tool for dynamic control of nematic ferroelectric order, with promising applications in the design of reconfigurable linear and nonlinear photonic devices.