Anti-resonant fiber with nested U-shape tubes for low-loss terahertz waveguides

Authors：Sun, Guangrong; Liu, Qiang^*; Mu, Haiwei; Sun, Yudan; Wang, Shimiao; Han, Mingzhu; Wang, Jianxin; Lv, Jingwei; Chu, Paul K.; Liu, Chao^*

Source：Optics and Laser Technology, 2023, 163: 109424.

DOI：10.1016/j.optlastec.2023.109424

• Anti-resonant fiber
• Terahertz
• High-resistivity silicon
• Low-loss transmission

A novel terahertz anti-resonant fiber is designed and described. The high-resistivity silicon in the fiber mitigating the effective material loss and the nested double-layer U-shape tubes work together to reduce the transmission loss. The confinement loss and effective material loss are analyzed and optimized by the finite element method. The optimized fiber shows a total loss of 3.1 x 10-3 dB/m at 1 THz and the low-loss transmission bandwidth is 0.44 THz in the range of 0.5-1.5 THz. The influence of bending on the transmission loss is analyzed and the bending loss is less than 2.1 x 10-2 dB/m at 1 THz for bending radii bigger than 60 cm. The anti-resonant fiber delivers excellent performance and has high commercial potential in terahertz waveguides.