Li Haisu, Ren Guobin, Zhu Bofeng, Gao Yixiao, Yin Bin, Wang Jing, Jian Shuisheng
Opt Lett. 2017 Jan 15;42(2):179-182. doi: 10.1364/OL.42.000179.
We explore terahertz (THz) orbital angular momentum (OAM) modes supported in multimode Kagome hollow-core fibers. Numerical models are adopted to characterize the effective indices and confinement losses of vector modes over 0.2-0.9 THz, where two low-loss transmission windows are observed. Linearly combining the vector modes, THz OAM states can be generated. Covering a broad bandwidth of 0.25 THz, the purity values of OAM modes are beyond 0.9. Using numerical simulations, the hollow-core THz fibers with one and two rings of Kagome structures are also comparably investigated. We reveal that the OAM purity is dependent upon the confinement performance of THz fiber.
我们研究了多模Kagome空心光纤中支持的太赫兹（THz）轨道角动量（OAM）模式。采用数值模型来表征0.2 - 0.9太赫兹范围内矢量模式的有效折射率和限制损耗，在此范围内观察到两个低损耗传输窗口。通过线性组合矢量模式，可以生成太赫兹OAM态。覆盖0.25太赫兹的宽带宽，OAM模式的纯度值超过0.9。利用数值模拟，还对具有一圈和两圈Kagome结构的空心太赫兹光纤进行了比较研究。我们发现OAM纯度取决于太赫兹光纤的限制性能。
