Holographic optical elements (HOEs) have a wide range of applications, including their emerging use in virtual and augmented reality displays, but their design and fabrication have remained largely limited to configurations using simple wavefronts. In this paper, we present a pipeline for the design, optimization, and fabrication of complex, customized HOEs that enhances their imaging performance and enables new applications. In particular, we propose an optimization method for grating vector fields that accounts for the unique selectivity properties of HOEs. We further show how our pipeline can be applied to two distinct HOE fabrication methods. The first uses a pair of freeform refractive elements to manufacture HOEs with high optical quality and precision. The second uses a holographic printer with two wavefront-modulating arms, enabling rapid prototyping. We propose a unified wavefront decomposition framework suitable for both fabrication approaches. To demonstrate the versatility of these methods, we fabricate and characterize a series of specialized HOEs, including an aspheric lens, a head-up display lens, a lens array, and, for the first time, a full-color caustic projection element.

中文翻译：

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自由形式全息光学元件的设计和制造

全息光学元件 (HOE) 具有广泛的应用，包括它们在虚拟和增强现实显示器中的新兴应用，但它们的设计和制造在很大程度上仍局限于使用简单波前的配置。在本文中，我们提出了一种复杂的定制 HOE 的设计、优化和制造流程，可增强其成像性能并实现新的应用。特别是，我们提出了一种光栅矢量场的优化方法，该方法考虑了 HOE 的独特选择性。我们进一步展示了我们的管道如何应用于两种不同的 HOE 制造方法。第一个使用一对自由曲面折射元件来制造具有高光学质量和精度的 HOE。第二种使用带有两个波前调制臂的全息打印机，实现快速原型制作。我们提出了一个适用于两种制造方法的统一波前分解框架。为了证明这些方法的多功能性，我们制造和表征了一系列专门的 HOE，包括非球面透镜、平视显示透镜、透镜阵列，以及首次全色焦散投影元件。