title: Guiding terahertz orbital angular momentum beams in multimode Kagome hollow-core fibers.
abstract: 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.
authors.forename: Haisu
authors.initials: H
authors.lastname: Li
authors.forename: Guobin
authors.initials: G
authors.lastname: Ren
authors.forename: Bofeng
authors.initials: B
authors.lastname: Zhu
authors.forename: Yixiao
authors.initials: Y
authors.lastname: Gao
authors.forename: Bin
authors.initials: B
authors.lastname: Yin
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Shuisheng
authors.initials: S
authors.lastname: Jian