In the present paper, a novel ultrahigh birefringent index-guided triangular-arrayed photonic crystal fiber with two small elliptical air holes in the core is proposed, which guides light by total internal reflection (TIR). The birefringence of PCFs is investigated using full-vector finite-element method. The impacts of the geometrical parameters and position of the elliptical air holes on the properties of birefringence are discussed. Our suggested structures show that the birefringence can be as high as 1.5x10 -2 at 1.55μm wavelength.
