HIGHLY BIREFRINGENT PHOTONIC CRYSTAL FIBER WITH NEGATIVE DISPERSION AND ITS PROPAGATION

In this paper we show a comparison of two hexagonal geometries of Photonic Crystal Fiber (PCF). These geometries are different with respect to the area of circular air holes. The area of circular air holes is kept fixed for a structure and is kept increasing and decreasing alternatively with increase in number of rings for another structure. Both structure considered consists of seven rings. The structure with variation in area of air-holes shows negative dispersion for a wide range of wavelength. The birefringence of PCF structure with variation in area of circular air hole is high compare to that of other proposed PCF structure. The confinement Loss reported is of the order of 10(-5) for both the PCF structure. But one of the structures with variation in area of circular air holes shows comparatively low confinement loss. The confinement factor was reported to be uniform for all the structures in this paper. The mode field pattern for both the structures appears to be a flower like shape with entire field being concentrated in the core and without leakage to cladding. The far field pattern (FFP) is also observed for both the structures.