Integrated vortex beam emitter in the THz frequency range: Design and simulation
Integrated vortex beam emitter in the THz frequency range: Design and simulation
复制标题
DOI：
10.1063/5.0010546
复制
发表时间：
2020-07
期刊：
影响因子：
--
通讯作者：
Hailong Pi;Tasmiat Rahman;S. Boden;T. Ma;Jize Yan;X. Fang
中科院分区：
文献类型：
--
作者：
Hailong Pi;Tasmiat Rahman;S. Boden;T. Ma;Jize Yan;X. Fang
紧凑型涡旋光束发射器已经成为光谱学、粒子操纵和通信等领域新应用的新光源。报道的设备依赖于线性光学现象，并在近红外（IR）制度发光。在这里，我们提出了一个非线性涡旋光束发射器，在太赫兹制度的功能和数值评估。该设计利用铌酸锂微晶，硅微盘，和一个Au二阶顶部光栅转换成自由传播的太赫兹光束通过差频产生波导耦合的IR光。输出光束携带可随输入波长调谐的拓扑电荷。在9 THz至13.5 THz的测试频率范围内评估了三个器件，拓扑电荷可以从-2变为4。频率偏移伴随着拓扑电荷的变化，其幅度取决于发射体的平面尺寸。
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.