Highly Birefringent Low-Loss Terahertz Waveguide: Elliptical Polymer Tube

Abstract

We propose an elliptical polymer tube (EPT) using as a highly birefringent low-loss Terahertz (THz) waveguide. High birefringence (up to the order of 0.01) is achieved due to the continuity of the electric displacement vector in the normal direction of the interfaces between the polymer materials and the air in the cross section of the EPT. Different properties of the effective index, mode area, power flow distribution and relative absorption loss for the x- and y-polarized fundamental modes of the proposed EPT are investigated. The relative absorption loss of the EPT is much lower than that of a solid elliptical polymer fiber. The birefringence property of the EPTs with different parameters is also calculated and discussed.