Dual-Porous Fiber-Based Low Loss Broadband Terahertz Polarization Splitter

A low loss broadband terahertz (THz) polarization splitter with a compact and simple structure has been proposed, which is based on the mode coupling between two porous fibers with orthogonally oriented cross section microstructures. The dispersion curves of the porous fibers are adjusted by the index converse matching coupling method. An interlacing stacking technique using polymer tubes and rods is presented for the fabrication of the proposed high-birefringence porous fiber. The characteristics of single porous fibers have been analyzed in detail. In addition, the dual-porous fiber-based polarization splitter has such desirable merits as ultrashort splitting length, low loss, and broad operation band. Compared with other dual-core PCF polarization splitters, this scheme possesses simpler structure, ease of fabrication, and better practical feasibility. This letter would be also of significance for the design of related broadband operation THz devices.