A new type of photonic crystal fiber (PCF) with pentagonal air-core is proposed, which consists of octagonal air holes in the cladding. In addition, five elliptical air holes are embedded in the inner layer to enhance the birefringence characteristic. Characteristics of this PCF are analyzed by using of Finite Element Method (FEM). Numerical results show that this kind of PCF exhibits high birefringence with the level of 0.001 after optimization, which will find application in optical sensing systems.
Dispersion and birefringence analysis of photonic crystal fiber with rhombus air-core structure