Abstract-Guiding terahertz orbital angular momentum beams in multimode Kagome hollow-core fibers

Haisu Li, Guobin Ren, Bofeng Zhu, Yixiao Gao, Bin Yin, Jing Wang, and Shuisheng Jian

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-42-2-179

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.

© 2017 Optical Society of America

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Abstract-3D Printed Hollow-Core Terahertz Optical Waveguides with Hyperuniform Disordered Dielectric Reflectors

http://onlinelibrary.wiley.com/doi/10.1002/adom.201600171/full

Novel hollow-core THz waveguides featuring hyperuniform disordered reflectors are proposed, fabricated, and characterized. The reflector comprises aperiodically positioned dielectric cylinders connected with dielectric bridges. The proposed waveguides are fabricated using a 3D MultiJet printer. Optical properties of the fabricated waveguides are investigated numerically using finite element method, as well as experimentally using terahertz time-domain spectroscopy. The results confirm that proposed waveguides exhibit sizable photonic bandgaps (21%) even with relatively low refractive index contrast (resin/air). Position of the bandgaps can be easily tuned by varying reflector geometrical parameters.