Design and Characterization of Porous Core Polarization Maintaining Photonic Crystal Fiber for THz Guidance

An improved design of Teflon photonic crystal fiber with a porous air-core is presented for low-loss terahertz guidance. Optimization of total power confinement in the air-holes, together both in the cladding and core regions, is carried out for both quasi-TE and quasi-TM polarizations by using a full-vectorial finite element method. To achieve the polarization maintenance, modal birefringence is enhanced by destroying the circular symmetry with the introduction of unequal size air-holes in the first ring.