Bend losses in flexible polyurethane antiresonant terahertz waveguides
Abstract
The quest for practical waveguides operating in the terahertz range faces two major hurdles: large losses and high rigidity. While recent years have been marked by remarkable progress in lowering the impact of material losses using hollow-core guidance, such waveguides are typically not flexible. Here we experimentally and numerically investigate antiresonant dielectric waveguides made of polyurethane, a commonly used dielectric with a low Young's modulus. The hollow-core nature of antiresonant fibers leads to low transmission losses using simple structures, whereas the low Young's modulus of polyurethane makes them extremely flexible. The structures presented enable millimeter-wave manipulation in centimeter-thick waveguides in the same spirit as conventional (visible- and near-IR-) optical fibers, i.e. conveniently and reconfigurably. We investigate two canonical antiresonant geometries formed by one- and six-tubes, experimentally comparing their transmission, bend losses and mode profiles. The waveguides under investigation have loss below 1 dB/cm in their sub-THz transmission bands, increasing by 1 dB/cm for a bend radius of about 10 cm, which is analogous to bending standard diameter fiber to a 1.2 mm radius.
Keywords
Cite
@article{arxiv.2105.12896,
title = {Bend losses in flexible polyurethane antiresonant terahertz waveguides},
author = {Alessio Stefani and Jonathan Skelton and Alessandro Tuniz},
journal= {arXiv preprint arXiv:2105.12896},
year = {2021}
}