Numerical analysis of a high-birefringent photonic quasi-crystal fiber with circular air holes

A high-birefringence(HB) photonic quasi-crystal fiber(PQF) with all-circular air holes is designed and ZrF₄-BaF₂-LaF₃-AlF₃-NaF(ZBLAN) is used to increase the birefringence and reduce confinement loss of the PQF in the infrared region. The structure of the PQF is analyzed and optimized numerically using the full-vector finite element method by adopting the perfectly matched layer boundary conditions. The PQF possesses higher birefringence in the wavelength range between 1.3 and 1.8μm and the maximum birefringence value of 4.1×10^-2 is achieved at 1.55μm. This is the highest birefringence value reported from all-circular-hole PQFs so far suggesting that the novel structure has great potential in high-performance optical devices.