Microstructured fiber links for THz communications and their fabrication using infinity printing

TL;DR

This paper introduces a novel infinity 3D printing technique for fabricating low-loss, high-performance THz fibers with complex geometries, demonstrating their potential for advanced terahertz communication systems.

Contribution

It presents the development and experimental validation of infinity 3D printing for continuous, complex THz fibers with low loss and high signal integrity, a significant advancement in fiber fabrication.

Findings

Achieved low transmission losses of 4.79 dB/m at 128 GHz

Demonstrated error-free data transmission up to 5.2 Gbps

Successfully visualized modal distributions via THz near-field imaging

Abstract

In this work, a novel infinity 3D printing technique is explored to fabricate continuous multi-meter-long low-loss near-zero dispersion suspended-core polypropylene fibers for application in terahertz (THz) communications. Particular attention is paid to process parameter optimization for 3D printing with low-loss polypropylene plastic. Three microstructured THz fibers were 3D printed using the standard and infinity 3D printers, and an in-depth theoretical and experimental comparison between the fibers were carried out. Transmission losses (by power) of 4.79 dB/m, 17.34 dB/m and 11.13 dB/m are experimentally demonstrated for the three fibers operating at 128 GHz. Signal transmission with BER far below the forward error correction limit (10-3) for the corresponding three fiber types of lengths of 2 m, 0.75 m and 1.6 m are observed, and an error-free transmission is realized at the bit rates up to 5.2 Gbps. THz imaging of the fiber near-field is used to visualize modal distributions and study optimal fiber excitation conditions. The ability of shielding the fundamental mode from the environment, mechanical robustness and ease of handling of thus developed effectively single-mode high optical performance fibers make them excellent candidates for upcoming fiber-assisted THz communications. Additionally, novel fused deposition modeling (FDM)-based infinity printing technique allows continuous fabrication of unlimited in length fibers of complex transverse geometries using advanced thermoplastic composites, which, in our opinion, is poised to become a key fabrication technique for advanced terahertz fiber manufacturing.