Computer-aided design software and additive manufacturing provide flexibility for the direct fabrication of multi-material devices. This design and fabrication versatility has been investigated for the manufacture of dielectric spiral phase plates (SPP) that generate electromagnetic waves with helical wavefronts. Three types of SPPs designed to produce an orbital angular momentum (OAM) mode number l = |1| were additively manufactured using material extrusion and polyjet fabrication methods. The OAM mode characteristics of the transformed helical microwaves as a function of the SPP geometrical features were investigated experimentally in the 12–18 GHz frequency range. The SPPs were further combined with an additively manufactured dielectric lens that provided a marked improvement in OAM mode purity. Finally, multiplexing and de-multiplexing of two OAM modes were demonstrated successfully using an optimum SPP geometry and arrangement.

计算机辅助设计软件和增材制造为直接制造多材料设备提供了灵活性。已经研究了这种设计和制造的多功能性，以制造介电螺旋相位板（SPP），该板会产生具有螺旋波前的电磁波。三种类型的SPP设计用于产生轨道角动量（OAM）模式编号l= | 1 | 使用材料挤出和多喷射制造方法相加制造。在12–18 GHz频率范围内，通过实验研究了转换后的螺旋微波的OAM模式特性与SPP几何特征的关系。SPP进一步与增材制造的介电透镜组合在一起，从而大大提高了OAM模式的纯度。最后，使用最佳的SPP几何结构和布置成功地演示了两种OAM模式的复用和解复用。