Co- and cross-polarization multiplexed liquid-crystal device for simultaneous near-field display and far-field holography.

Liquid crystal (LC) has been widely utilized in advanced light modulation with the development of photoalignment techniques. However, most conventional LC devices usually exploit only the cross-polarized output field for wavefront shaping, while the co-polarized channel is treated as residual leakage and discarded. Here, we show that this unused channel can be converted into an additional information-coding channel and demonstrate that the two polarization channels enable complementary near-field intensity modulation and polarization-selective far-field holographic reconstruction within a single LC device. A dual-channel constrained algorithm is jointly developed for both near-field grayscale image and far-field holography optimization, and the sample can be fabricated by simply varying LC orientation, which is compatible with the photoalignment equipment. The device exhibits broadband performance and is verified at three wavelengths of 445, 520, and 638 nm. We believe that this work provides a scalable platform for multifunctional photonic devices for optical encryption and advanced displays.