Low-loss terahertz negative curvature suspended-core fiber

Abstract: Inspired by the design concept of negative curvature hollow-core fibers, this paper presents an innovative negative curvature suspended-core THz fiber. Compared to traditional suspended-core fibers, all structural units of this fiber are designed with circular boundaries, effectively avoiding the issues of insufficient mechanical strength and manufacturing difficulties associated with the wide and ultra-thin rectangular support arms in traditional structures. The numerical simulation using the full-vector finite element method shows that the optical fiber loss is as low as 0.0868dB/cm (0.02cm-1) in 0.4-0.9THz, and the low loss bandwidth is 0.43THz. In addition, by adjusting the structural parameters of the fiber, near zero flat dispersion of -0.15-0.05 ps/THz/cm can be achieved in the range of 0.4-0.9 THz. The fiber exhibits excellent characteristics of low loss, wide bandwidth, and low dispersion, theoretically opening a new research path for the design of low loss THz fibers. This will provide important component support for the application and development of THz technology in fields such as communication, sensing, and imaging.