The evolution of computer-generated holography (CGH) algorithms has prompted significant improvements in the performances of holographic displays. Nonetheless, they start to encounter a limited degree of freedom in CGH optimization and physical constraints stemming from the coherent nature of holograms. To surpass the physical limitations, we consider polarization as a new degree of freedom by utilizing a novel optical platform called metasurface. Polarization-multiplexing metasurfaces enable incoherent-like behavior in holographic displays due to the mutual incoherence of orthogonal polarization states. We leverage this unique characteristic of a metasurface by integrating it into a holographic display and exploiting polarization diversity to bring an additional degree of freedom for CGH algorithms. To minimize the speckle noise while maximizing the image quality, we devise a fully differentiable optimization pipeline by taking into account the metasurface proxy model, thereby jointly optimizing spatial light modulator phase patterns and geometric parameters of metasurface nanostructures. We evaluate the metasurface-enabled depolarized holography through simulations and experiments, demonstrating its ability to reduce speckle noise and enhance image quality.

翻译：计算机生成全息（CGH）算法的演进显著提升了全息显示的性能。然而，它们开始面临CGH优化自由度受限以及全息图相干特性带来的物理约束。为突破物理限制，我们利用一种名为超表面的新型光学平台，将偏振视为新的自由度。偏振复用超表面因正交偏振态之间的相互非相干性，能够在全息显示中实现类非相干行为。我们通过将超表面集成到全息显示系统中，利用偏振多样性为CGH算法引入额外自由度，从而发挥其独特特性。为在最小化散斑噪声的同时最大化图像质量，我们设计了一个完全可微的优化流水线，该流水线通过引入超表面代理模型，联合优化空间光调制器相位模式与超表面纳米结构的几何参数。我们通过仿真与实验评估了基于超表面的去偏振全息技术，证明了其降低散斑噪声与提升图像质量的能力。