Volumetric computer-generated diffractive optics offer advantages over planar 2D implementations, including the generation of space-variant functions and the multiplexing of information in space or frequency domains. Unfortunately, despite remarkable progress, fabrication of high volumetric space-bandwidth micro- and nano-structures is still in its infancy. Furthermore, existing 3D diffractive optics implementations are static while programmable volumetric spatial light modulators (SLMs) are still years or decades away. In order to address these shortcomings, we propose the implementation of volumetric diffractive optics equivalent functionality via cascaded planar elements. To illustrate the principle, we design 3D diffractive optics and implement a two-layer continuous phase-only design on a single SLM with a folded setup. The system provides dynamic and efficient multiplexing capability. Numerical and experimental results show this approach improves system performance such as diffraction efficiency, spatial/spectral selectivity, and number of multiplexing functions relative to 2D devices while providing dynamic large space-bandwidth relative to current static volume diffractive optics. The limitations and capabilities of dynamic 3D diffractive optics are discussed.

中文翻译：

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3D衍射光学的动态2D实现

体积计算机生成的衍射光学器件具有优于平面2D实现的优势，包括空间变量函数的生成以及空间或频域中信息的复用。不幸的是，尽管取得了显着进展，但高体积空间带宽的微米和纳米结构的制造仍处于起步阶段。此外，现有的3D衍射光学实现是静态的，而可编程体积空间光调制器（SLM）仍需要数年或数十年的路程。为了解决这些缺点，我们建议通过级联的平面元件实现体积衍射光学等效功能。为了说明该原理，我们设计了3D衍射光学器件，并在具有折叠设置的单个SLM上实施了两层仅连续相的设计。该系统提供了动态高效的多路复用功能。数值和实验结果表明，这种方法改善了系统性能，例如相对于2D器件的衍射效率，空间/光谱选择性和多路复用功能的数量，同时相对于当前的静态体积衍射光学器件提供了动态的大空间带宽。讨论了动态3D衍射光学的局限性和功能。