Complex Amplitude Holography Enabled by Dual‐Layer Liquid Crystal Structures

ABSTRACT Among the various platforms for optical wavefront shaping, liquid‐crystal (LC) devices remain the most widely adopted due to their high efficiency, programmability, and low driving voltage. However, realizing complex‐amplitude modulation with LC remains several challenges: single‐layer LC devices are inherently restricted to either phase‐only or amplitude‐only modulation, and the conversion of complex wavefronts into pure phase or amplitude wavefronts unavoidably sacrifices spatial resolution. To overcome these limitations, we propose a dual‐layer cascaded LC strategy to achieve continuous and decoupled complex‐amplitude modulation by individually controlling the orientation angles of LC molecules in two cascaded layers. The complex‐amplitude modulation originates from the fact that there are two independent phase‐only components generated by each LC layer through the geometric phase mechanism, and the coherent superposition of these two components. To verify the theory, we design a complex‐amplitude hologram to generate a holographic light sheet on planes parallel to the optical axis, and the measured intensity distributions exhibit excellent agreement with the simulation. The approach can provide an effective solution for complex‐amplitude modulation and promote the potential application of cascaded LC architectures in multidimensional optical field manipulation.