Nonlinear holography has recently emerged as a novel tool to reconstruct the encoded information at a new wavelength, which has important applications in optical display and optical encryption. However, this scheme still struggles with low conversion efficiency and ineffective multiplexing. In this work, we demonstrate a quasi-phase-matching (QPM) -division multiplexing holography in a three-dimensional (3D) nonlinear photonic crystal (NPC). 3D NPC works as a nonlinear hologram, in which multiple images are distributed into different Ewald spheres in reciprocal space. The reciprocal vectors locating in a given Ewald sphere are capable of fulfilling the complete QPM conditions for the high-efficiency reconstruction of the target image at the second-harmonic (SH) wave. One can easily switch the reconstructed SH images by changing the QPM condition. The multiplexing capacity is scalable with the period number of 3D NPC. Our work provides a promising strategy to achieve highly efficient nonlinear multiplexing holography for high-security and high-density storage of optical information.

非线性全息术最近作为一种以新波长重建编码信息的新工具而出现，在光学显示和光学加密中具有重要应用。然而，该方案仍然存在转换效率低和复用效率低的问题。在这项工作中，我们展示了三维 (3D) 非线性光子晶体 (NPC) 中的准相位匹配 (QPM) 分割复用全息术。3D NPC 作为非线性全息图工作，其中多个图像分布在互易空间中的不同 Ewald 球体中。位于给定 Ewald 球体中的倒易矢量能够满足在二次谐波 (SH) 波处高效重建目标图像的完整 QPM 条件。可以通过改变 QPM 条件轻松切换重建的 SH 图像。复用容量可随 3D NPC 的周期数而扩展。我们的工作提供了一种有前途的策略，可以实现高效的非线性多路复用全息技术，以实现光学信息的高安全性和高密度存储。