Advances in additive manufacturing have enabled the realisation of inexpensive, scalable, diffractive acoustic lenses that can be used to generate complex acoustic fields via phase and/or amplitude modulation. However, the design of these holograms relies on a thin-element approximation adapted from optics which can severely limit the fidelity of the realised acoustic field. Here, we introduce physics-based acoustic holograms with a complex internal structure. The structures are designed using a differentiable acoustic model with manufacturing constraints via optimisation of the acoustic property distribution within the hologram. The holograms can be fabricated simply and inexpensively using contemporary 3D printers. Experimental measurements demonstrate a significant improvement compared to conventional thin-element holograms.

翻译：增材制造技术的进步使得低成本、可扩展的衍射声学透镜得以实现，这些透镜可通过相位和/或振幅调制生成复杂声场。然而，此类全息图的设计依赖于从光学领域移植而来的薄元件近似模型，这种近似会严重限制所实现声场的保真度。本文提出了一种具有复杂内部结构的物理声全息图。这些结构通过可微声学模型进行设计，并在制造约束下优化全息图内部的声学属性分布。该全息图可通过现代3D打印机简单、低成本地制备。实验测量表明，相较于传统薄元件全息图，其性能得到了显著提升。