High Birefringent Terahertz Photonic Crystal Fiber Based on Material-Filled Structure

Abstract

A novel kind of high birefringent terahertz (THz) photonic crystal fibers (PCFs) with material-filled structure is proposed in this paper. Based on the material-filled technology, which different materials are selectively filled into four air holes of the inner first circle near the central core in the designed THz PCFs, high birefringence are obtained from the structural and material-filled induced asymmetry in large frequency ranges near 1THz. Modal birefringence with different structural parameters and diverse refractive indices of the filled materials are investigated by plane wave expansion (PWE) method. The numerical results show that high birefringence up to 10-3can be obtained and its structure is simpler than that of the early proposed highly birefringent THz PCFs. It is helpful for PCFs design and real fabrication in the potential THz applications.