Independent Amplitude‐Phase Control in Liquid Crystal for Near‐Field Anti‐Counterfeiting and Far‐Field Holographic Encryption

ABSTRACT Liquid crystal (LC) optical devices provide a promising platform for optical encryption and anti‐counterfeiting applications. However, conventional design paradigms for LC light‐field modulation often involve coupled amplitude and phase responses, limiting design flexibility and information multiplexing capability. Here, we propose a macro‐pixel LC design strategy that enables complex‐amplitude modulation through the coherent superposition of light fields from paired sub‐pixels. In each macro‐pixel, the difference and sum of the LC molecular orientation angles between adjacent sub‐pixel units are tailored to independently control and encode the amplitude and phase of the light field, respectively. This design produces polarization‐insensitive near‐field amplitude modulation, while its spin‐dependent phase response enables polarization‐selective far‐field holographic reconstruction. By further exploiting the distance selectivity of light propagation, we construct an optical security device that encodes a directly observable near‐field anti‐counterfeiting pattern and multiple hidden far‐field holographic images into the same architecture. The hidden holographic information is selectively reconstructed only when the incident polarization state and propagation distance match the predefined physical readout conditions. This macro‐pixel strategy expands the light‐field modulation capability of LC devices and offers a compact route toward near‐ and far‐field information multiplexing, multichannel holographic encryption, and multilevel optical authentication.