Compact vortex beam emitters have emerged as new light sources for novel applications in areas including spectroscopy, particle manipulation, and communications. Reported devices depend on linear optical phenomena and emit light in the near-infrared (IR) regime. Here, we propose and numerically evaluate a nonlinear vortex beam emitter that functions in the THz regime. The design utilizes a LiNbO₃ microring, a Si microdisk, and an Au second-order top grating to convert waveguide-coupled IR light into a freely propagating THz beam via a difference-frequency generation. The output beam carries a topological charge that is tunable with input wavelengths. Three devices are evaluated in a test frequency range from 9 THz to 13.5 THz, and the topological charge can change from −2 to 4. A frequency shift accompanies the change in the topological charge, and its magnitude depends on the planar dimensions of the emitter.

中文翻译：

---

太赫兹频率范围内的集成涡旋光束发射器：设计和仿真

紧凑型涡旋光束发射器已成为新的光源，可用于光谱，粒子处理和通信等领域的新型应用。报告的设备依赖于线性光学现象，并以近红外（IR）方式发光。在这里，我们提出并在数值上评估了在THz范围内起作用的非线性涡旋束发射器。该设计利用了LiNbO ₃微环，Si微盘和Au二阶顶部光栅，通过差频生成将波导耦合的IR光转换为自由传播​​的THz光束。输出光束带有可随输入波长调整的拓扑电荷。在9 THz至13.5 THz的测试频率范围内评估了三种器件，拓扑电荷可从-2变为4。拓扑电荷的变化伴随着频率偏移，其幅度取决于发射极的平面尺寸。