Low loss and near-zero dispersion suspended core polypropylene fibers printed with standard and infinite FDM-based 3D printers for THz communication

In this work, a novel infinite 3D printing technique is explored to fabricate continuous several-meter-long low-loss and near-zero dispersion suspended-core polypropylene fibers for application in terahertz communications. Furthermore, particular attention is paid to process parameter optimization for printing with low-loss polypropylene plastic, as well as an in-depth theoretical and experimental comparison between fibers printed using standard and infinite 3D printers. Fiber transmission losses as low as 2.42 dB/m and 8.86 dB/m are experimentally demonstrated for the two fibers respectively at 128 GHz. Signal transmission with BER far below forward error correction limit (10-3) are clearly observed, an error-free transmission is realized at the bit rate up to 5 Gbps. The optimal conditions for exciting fibers and the mode field distributions are present intuitively with the near-field imaging. The capabilities of shielding the fundamental mode from external interference granting unique superiorities of easy-handling and convenient-fixing to these effectively single-mode 3D printed fibers. The novel fused deposition modeling (FDM)- based infinite printing technique in our opinion is poised to become a key technique for advanced terahertz fiber manufacturing.