Polymer optical fibers for Terahertz: Low loss propagation and high evanescent field

In this paper, there are three different polymer optical fibers in THz range were investigated: a microwire, a tube and a porous fiber. The effective index of fundamental mode and the power fraction distribution in the material, the air cladding and within the air holes regions were detailed studied when the geometrical parameters were changed. The results show that all the structures have large power fraction being transmitted in air, around 60%, where absorption losses are greatly reduced, improving their application as evanescent field sensors.