Liquid–crystal-enabled dynamic optical coherence modulation for optical imaging

Abstract Optical coherence is a fundamental yet underexploited degree of freedom for controlling light–matter interactions, with far-reaching implications for imaging, information processing, and photonic computing. Despite decades of progress, dynamic coherence control has remained constrained by an inherent trade-off: low efficiency, bulky system footprints, and limited dynamic tunability. These limitations severely constrain the integration and miniaturization of coherence-engineered photonic systems. Here, we propose and experimentally demonstrate a dynamic Pancharatnam–Berry phase nematic liquid–crystal device, photopatterned with programmable ultraviolet polarization, which addresses several key challenges in conventional coherence-control approaches, including compactness, reversibility, and dynamic tunability. By exploiting the electro-optical reorientation of soft-matter liquid crystals, our platform enables on-demand, reversible modulation of optical coherence within a millimeter-scale device, achieving a modulation efficiency up to 70% and a response time of 20 ms. This approach realizes continuous and fully dynamic coherence tuning, spanning the entire range from nearly coherent to nearly incoherent illumination. Beyond its fundamental significance, the demonstrated capability enables enhanced optical performance in scattering environments, including speckle-free imaging and dynamically reconfigurable “smart-window” functionality. Our results establish liquid–crystal–enabled coherence engineering as a compact, efficient, and scalable solution, opening a practical pathway toward integrated and miniaturized photonic systems for next-generation imaging, encryption, and photonic computing.